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Western Historic Radio Museum

E.F. Johnson Co. - Viking Transmitters

Viking 1 - The "W7TC" Viking 1 - Rebuilding for a Second or Third or Fourth Time Around

Viking Ranger - The KK7EI Transmitter and the Exciter for the Desk KW

Viking Desk KW - Found Disassembled at the University of Nevada - Reno

Viking KW Matchbox - The Ultimate Balanced Antenna Matching Device

Viking Navigator - The Navigator DeLuxe - or - How to Get Rid of that Worthless
Iron Vane Meter and Install an Accurate Viking Ranger Meter making the transmitter a "Navigator DeLuxe"

The Viking 1 Transmitter  ca: 1950

The Viking 1 was first rebuilt in 2008 for W7TC, a longtime ham-friend of mine. Sixteen years later, after "TC" went SK, I then owned that same Viking 1. I went through it in 2024 and again for the end of 2025. Lots of details on the Viking 1 (it's approaching OCD) but some interesting finds on the Johnson Mod "B" along with info on the transmitter bias voltages and the adjustable B+ divider-resistor and how those can seriously affect the transmitted signal quality these voltages are not adjusted carefully. The manual instructions makes use of the Mod current meter to adjust the Screen B+ but that assumes that the meter shunt is accurate. Much more accurate methods and equipment are easily available nowadays to adjust all of the voltages in the Viking 1 for excellent performance. Shunt soldering problems can seriously affect the meter accuracy because of the very low resistance values.

The Viking Ranger was Sharon's Novice transmitter in 1975. She was WN7AZE then, she's now KK7EI. The Ranger has been rebuilt a time-or-two and had a near-catastrophic disaster while helping out Ham & Hi Fi test out a Desk KW they had. A Ranger "parts set" was required for that repair (which was provided at no charge by Ham & Hi Fi.)

The Viking Desk KW was disassembled on the second floor of the Electronic Bldg. at UNR. I got a "'phone tip" from my old friend N7PSA (now W4YBS) and I was able to make a purchase just before it was to be parted-out.

The Viking KW Matchbox shows how a true balanced antenna matching device should work. It's such a good design, I have two of them. Three, if you count the little 275W version.

If, like me, you absolutely HATE the original Navigator iron-vane meter, this section shows how I eliminated that cheap-o, piece-of-junk, iron-vane meter and replaced it with a genuine E.F. Johnson Viking Ranger. It's a real D'Arsonval meter movement that's a lot more accurate, it has an illuminated scale and the scale even has the "Viking's Head" logo on it. It's what Johnson wanted to install but that would have made the Navigator even more expensive than it already was. I've included the "how to" instructions for changing the plain-old Navigator into the "Navigator DeLuxe," something that E. F. Johnson would certainly approve of. 

E. F. Johnson Co. - Viking 1 Transmitter Kit

The E. F. Johnson Viking 1 Transmitter Kit

The Viking 1 History - Introduced in late-1949, E. F. Johnson Co. entered into the ham transmitter market with the Viking 1 Transmitter Kit priced at $209. Edgar Johnson had been in business since the early-1920s building components for transmitters and ceramic insulators for their "Q" antenna systems. In 1947, they purchased Speed-X from Les Logan and started to provide both straight keys and speed keys. Starting with the Viking 1, Johnson went into the ham transmitter market and quickly expanded their equipment line, becoming one of the top ham transmitter producers in the late-1950s up through the late-1960s. Unfortunately, rather than developing modern, improved ham transmitters in the late-1960s, Johnson decided to dive into the new Citizen's Band market place. They sold their Speed-X line to William Nye and ended all ham equipment production in the early-1970s. The CB market didn't last and Johnson couldn't compete with the imported Japanese ham gear, so the company went back to just producing small components which are still their main products today.

The Viking 1 Circuit - The transmitter used a Raytheon 4D32 as the PA modulated by a pair of 807 tubes. There were instructions included to change the final to an easier to obtain surplus 829B tube that produced about the same power output. The Crystal Oscillator was a 6AU6 tube and the Buffer/Doubler was a 6AQ5 tube. The speech amp was a 6AU6 and the audio driver tube was another 6AU6. Negative feedback was included in the speech amplifier to improve audio quality although the actual gain in the speech amplifier and audio driver stage wasn't sufficient to fully modulate the transmitter. The rectifiers consisted of a parallel set of 5R4 tubes for the +HV, a single 5Z4 tube for the +LV and a 6AL5 bias voltage rectifier. Ten crystals could be installed on the chassis and then front panel switch-selected for convenient QSYing but most users opt'd for the Johnson Model 122 VFO when it became available. The input power at the 4D32 PA was 150 watts on phone or CW. Output power was guaranteed to be at least 100 watts into a 50Z load. The output matching used a Pi-network. All parts were included with the Viking 1 kit including a pre-assembled harness that eased the wiring, an already punched aluminum chassis, a silk-screened steel front panel and a table cabinet (early cabinets were aluminum, later cabinets were steel that added quite a bit of weight.)

Obtuse Assembly Instructions - The assembly instructions were difficult to use. Very few photos of the assembly process were included and absolutely NO drawings showing details for the more difficult assemblies. Step-by-step written instructions had to be followed and each step was numbered with the intention that the assembler would "check off" the steps as they were completed. Of the numerous radio kits that I've rebuilt, by far, the Viking 1 assembly instructions are the most difficult to follow. Additionally, even the tube layout isn't provided in the manual. One has to use the chassis assembly layout that provided "X" socket numbers and then correlate that to the "V" tube ID number on the schematic - unbelievable! Of course, it's not at all difficult to actually know which tubes go where since the circuit is pretty basic, but still,...most kit instructions assume you're not very experienced and need all the help you can get. But,...not at Johnson. Due to the obtuse assembly instructions, most Viking 1 transmitters seem to have a lot of evidence of rework here and there. Probably from assembly mistakes. Apparently all of the Johnson kit assembly instructions were difficult to follow. I had a Johnson 500 around 1991 that had originally been a kit. The harness had several wires inside that had burned up due to wiring mistakes. There were 42(!) wiring errors in that "500" and at least half of them were probably due to poor assembly instructions with NO drawings and only a few photos (I'm sure the builder's inexperience was the major factor.)   

160M IN-OUT Switch - Fortunately, the Viking 1 circuit is basic and the chassis doesn't really have anything that is difficult to access,...except the "160M IN-OUT" pulley-driven switch. I know it was a "last minute design thought" to include 160M on the transmitter but this switch really is "Rube Goldberg." The problem is that the pulley-drive set up has to be fully assembled before the Pi-network is mounted to the chassis and before the front panel installed.

The "TC" Viking 1 (shown in the photos) never had the dial string installed to make the 160M IN-OUT switch pulley-drive system work. The initial assembler must have thought "I'll never work 160M. Who cares." Well, 160M capability is one of the great features on the Viking 1 and that meant the 160M IN-OUT switch had to function. Installing the dial cord onto the two pulleys, one on top of the chassis and one underneath, can't be accomplished after the Pi-network assembly is completed. To install the dial cord required that the Pi-network be partially disassembled and removed in order to "string the pulleys" and get the 160M IN-OUT switch to function. Since the Viking 1 was designed to be built by hams, the disassembly of the Pi-network is really pretty easy.

My First Viking 1,...ca. 1990 - I've owned two different Viking 1 transmitters. The first one was purchased around 1990. It had come out of the National Guard Armory in Carson City, Nevada. This transmitter was in fantastic cosmetic condition but, despite what the seller told me about how nice of a transmitter it was, it really didn't function very well at all. All of the electrolytic filter capacitors were bad and had to be replaced. I replaced the electrolytics and also the paper dielectric capacitors. That got the Viking 1 working okay. It seemed that 100% negative modulation was impossible to achieve, even with the Audio Gain at maximum. Then I found out about "Johnson Mod B" - a product of the engineers at Johnson responding to that exact "stock" modulation problem.

That first Viking 1 did get used quite a bit and I even wrote up an article for the Carson Valley (Minden, NV) Ham Club Newsletter about that Viking 1 used in combination with a National HRO-5TA1 receiver I had (still have.) I even used the first Viking 1 on 160M CW a few times. I had many high-speed CW practice QSOs with W7TC using my first Viking 1. I didn't use the Viking 1 after moving to Virginia City in 1993 and ended up selling it around 1999. 

The "TC" Viking 1

My Second Viking 1 - THE "TC" VIKING 1 - I first encountered my second Viking 1 shown here in these photos in 2008. My old friend, Tom Corditch W7TC (now SK) became interested in having a Viking 1 for some reason. He had found or had purchased three of them. One had a very nice front panel but the chassis was virtually destroyed by hacked-in modifications. The second transmitter had a very nice chassis but the front panel was really beat-up and so was the cabinet. The last transmitter was just a chassis that was used for a parts source. "TC" wanted me to "build" a nice, working Viking 1 for him using these three examples he had found.

The rebuild used the good condition chassis to start. This chassis was the earlier type without any TVI modifications. The best parts from the other two chassis were transplanted as needed. I had to entirely rebuild the Pi-network using parts from both of the "parts sets." The nice front panel was further cleaned and given a very gentle rubdown using Wenol's polish. I didn't want the panel to be glossy but to just have a slight sheen. The front panel was the later version (a TVI kit that could be purchased to install on the Viking 1) that had holes along the upper edges. This was for TVI shielding that had been taken off in the past. The holes were filled with a dozen screws and nuts. The meter shield was also something found on later TVI'd Viking 1 transmitters. A good set of knobs were cleaned and polished. I found that the chassis had just a portion of Mod B installed, so I completed the installation of Mod B. All paper dielectric caps were changed to new polyfilm types. New electrolytic capacitors throughout. A "zip cord" line was brought out to drive a Dow Key relay that would operate in parallel with the Plate switch. "TC" also had acquired a Johnson Model 122 VFO that had a few problems with unsoldered connections that created some unstable output. Fortunately, I kept a list of all of the problems to give to "TC" and now, 16 years later, I have that very same list. It shows that 30 steps of assembly or operational problems were found in completing the job. I was surprised in rereading this list at how many problems were related to poor soldering. But, after rebuilding several ham radio kits now,...maybe I'm not that surprised. I ended up delivering the complete and functional Viking 1 and the Model 122 VFO to "TC" in March of 2008.

"TC" used the Viking 1 quite a bit. He even used it through an attenuator to drive a Johnson Thunderbolt amplifier. In 2015, "TC" went SK. I handled the deposition of his ham gear for his XYL. The Model 122 VFO was gone, I never did find it. The Thunderbolt had gone to W6AQU Bob in Montegue, California. The Viking 1 was sold to KØDWC here in Dayton. "DWC" had to buy a Model 122 VFO off of eBay but eventually did get the Viking 1 on the air a few times. He also "touched up" the cabinet with official Johnson brown paint although it wasn't wrinkle finish paint. With other distracting interests, "DWC" had packed the Viking 1 away in storage. In 2023, "DWC" had expressed an interest in acquiring a BC-224 receiver. I knew he still had the "TC" Viking 1 stored away, so I proposed a trade,...a really nice, working BC-224 with dynamotor and shock mount for the "TC" Viking 1 and a Model 122 VFO. The trade happened on Jan 2, 2024. To me, this wasn't just any old Viking 1. This was the one that I personally had built for "TC" so I really had a special interest in preserving this transmitter.

Viking 1 top of the chassis

I found that the chassis had a light-grease film on it that cleaned off with WD-40. I thoroughly cleaned the ceramic sockets of dirt and grease. I removed the 1meg grid load on the speech amplifier and replaced it with a 4.7meg resistor (as a test - not very good results. Ended up with a 1.3meg.) The resistor has to be entirely shielded and that requires insulating the grid lead from the shield. I used heat shrink tubing for insulation on the grid lead.   >>>

Viking 1 under the chassis
The two insulated wire "coils" in the center of the chassis are the shunts for PA and MOD current

There isn't any "push-to-talk" circuitry in the Viking 1. Also, there wasn't a socket to provide power for a T-R relay. Most Viking 1 transmitters will have wiring from the Plate switch that turns on the Plate transformer primary with 115vac and parallel wires in the form of a "zip cord" routed out through the AC power cord hole in the chassis in order to have 115vac available for a Dow Key relay when the Plate switch is ON.

There isn't any voltage regulation in the Viking 1. The Model 122 VFO does have a 0A2 voltage regulator.

The Viking 1 is cathode keyed in the CW mode. Blocked-grid keying was used in later Johnson transmitters.

I moved the Viking 1 to the shack and connected it to the Collinear Array antenna via the Johnson Matchbox. I was able to get slightly over 100 watts output when loaded to about 270mA of plate current with a 1:1 match on the antenna. I used a D-104 crystal mike on an Atlas stand, so no preamp, just the crystal element directly to the transmitter. No PTT on the Viking 1, so a grip stand wasn't needed. I thought the 4D32 is a little flat so I pulled a pretty new one out of the 32V-1 transmitter. The tube hadn't been in operation for about a year, so I let it warm up for ten minutes before trying it. I could get just over 100 watts. I tried a 4D32 that was in a 32V-2 I had in storage and it tested exactly the same. The test showed the all three good 4D32s worked exactly the same way. But, I don't know about the accuracy of the Drake W-4 wattmeter. I only use it for adjusting the Matchbox for a null in reflected power. I do know that the 32V-3 shows 110 watts output using the same W-4 wattmeter and the same antenna set up. So the Viking 1 does have slightly less output power than a Collins 32V-3. Probably because I run the 32V-3 at +700vdc Plate voltage and the Viking 1 runs about +600vdc Plate voltage.

Jan 7, 2024 - On the Air - I operated the Viking 1 on the Nevada Vintage Mil-Rad Net on 75 meters. No problems, all good compliments although one "bassy sounding audio" comment (I don't know if it was a compliment or a critique.) I haven't listened to myself on a monitor receiver yet. I didn't use a T-R relay but went directly to the Collinear Array through the Matchbox. The Meissner Traffic Scout receiver operated off of the Pixel Loop. I did this for a quick and simple set up for testing.

Feb 4, 2024 - Audio Testing - After the "bassy sounding audio" remark, I had to listen to the Viking 1 myself. By far the easiest way to listen to my audio is to go to N9AMI's Wavelength Radio youtube channel. John N9AMI records the Nevada Vintage Mil-Rad net and has the recordings available on his youtube channel. These recordings are of actual signals that are received "over the air" at John's QTH (about 25 miles east of my QTH in Dayton,) so I can get a pretty good idea of how a particular transmitter sounds. The Viking 1 sounds nice. Nothing really stands out. The audio bandwidth seems normal with no excessive bass. The sound is natural. There's enough bass response so that the signal doesn't sound thin like so many early Johnson-Viking transmitters do. I think the 4.7meg grid load (that I had installed then) in combination with the D-104 element directly connected to the first audio amplifier grid provides just the right amount of naturalness for the Viking 1 with Mod B installed. So, thanks to John N9AMI and his Wavelength Radio youtube channel, I actually got to listen to how the Viking 1 sounded myself.  

The "TC" Viking 1 with the Model 122 VFO
Steel Cabinet and TVI Shielding Front Panel

More Problems with the Viking 1

As it turns out,...there were several more problems with the Viking 1 involving incorrect voltage levels, incorrect bias levels, burned resistors, resistors that had drifted in value and much more. I don't know whether I missed that on the first rebuild or, the more likely explanation, is that these problems developed over the next sixteen ensuing years between 2008 and 2024. I'm not really sure how "TC" operated this Viking 1, especially when he was using it to drive the Johnson Thunderbolt. At any rate, I had operated the Viking 1 three times "on the air" before I actually got a definitive report that described the problems with the signal. So, even listening to an "over-the -air" recording doesn't tell you everything about your signal. I should have paid more attention to the modulation oscilloscope pattern. The 'scope showed there was a problem but obviously I just ignored it.

As long as I had the chassis out of the cabinet I thought I should probably take care of some other minor issues.

1. First, when selecting the meter function, it seemed that the Plate current would read differently each time the switch was operated so I thoroughly cleaned the switch with DeOxit and a small brush. I also cleaned the Oscillator band switch although there wasn't really any problem there. Seems a little more consistent in the PA I reading now. Next time I have the Viking 1 out of the cabinet I'm going to resolder the shunt connections and the wire connections to the Meter switch. UPDATE: The refurb in Dec. 2025 found that these erratic meter reads were caused by very poor soldering of the two shunts for Plate and Mod measurements and the common chassis connection for the two shunts didn't have the solder lug tightened so the chassis-ground was not a solid connection.
2. Then there was the FIL pilot lamp that could hardly be seen and was erratic in operation. The bulb was loose and that caused the erratic operation but the lamp was a #40 (.155A) so I replaced it with a #46 (.250A) for greater brightness. Works great.
3. Then there were the twelve screws and nuts that were "hole fillers" in the panel. Although I'd like to just fill the holes and match the touch-up paint, with twelve holes,...any slight mismatch would be obvious. So, I decided to paint the screw heads gray and that way any mismatch wouldn't be a problem and the gray screw heads would blend with the panel. Looks better, not great but okay. UPDATE: Dec 2025 refurb got rid of this front panel. Details further down.
4. Then there was the misalignment of the FINAL dial to the index plate. That just required some more adjustment of the bezel and index plate to have it be a close fit. Looks and works fine.
5. Finally, I hadn't noticed how stiff, cracked and aged the power cord was. It's nothing special as far as appearance, so I replaced it with a similar-looking length of new 16 gauge brown "zip cord." I also replaced the heavy gauge zip cord and AC socket for the Dow-Key power to now using a very small zip cord and small AC socket. This was to allow both AC zip cords to easily fit through the chassis grommet.

It Seems That Other Problems were the Actual Cause of the Weak Audio - Since I really couldn't find anything that was blatantly wrong in the audio section, I started to carefully examine ALL of the transmitter circuitry and components. I noticed that the negative bias voltages are derived from a divider made up of several 1W CC resistors. Those have to be checked because incorrect negative bias voltage could cause problems in the modulator. Also, there is a larger 20K WW resistor R13 acting as a voltage divider that determines the level of the +300vdc plate voltage for the Speech Amp, Oscillator, Buffer and the Modulator Screen sections and that has to be checked. The plate load for the Buffer R26 is discolored and swollen that needs to be checked. I suppose my first assumption was that I had gone over this Viking 1 in 2008, so everything should be fine,...but that's certainly not true today. I don't know if I missed these potential problems 16 years ago but that's certainly possible,...I do remember that when "TC" was operating this Viking 1 his audio always seemed a little on the "light side" and he was only six miles away. At any rate, I need to thoroughly inspect ALL of the Viking 1 for the condition that it is in now.

ON THE AIR Results - Apr 28, 2024 - I have the Viking 1 set up with the National NC-183 receiver. They are contemporary with each other and comprise a believable circa 1950 ham station. As usual, it's very difficult to get detailed audio reports "on the air" so it's lucky that Wavelength Radio records most of the NV Mil-Rad Nets. I listened to Wavelength Radio's recording of the net and the Viking 1 has never sounded as good as it does now. And, looking at the recording's panadaptor, the spectrum is now filled with audio and it looks like the bandwidth is minimum 6kc and maybe even a bit more. It's a very helpful resource that John N9AMI provides in the Wavelength Radio recordings of many nets and other interesting ham video and audio recordings on his youtube channel. 

The Viking 1 with the National NC-183
 

Refurb #4 - Getting Rid of the Steel Cabinet and the TVI Front Panel

I never liked the looks of the dozen TVI screws on the front panel of this Viking 1. Then there was the steel cabinet. I just couldn't believe how much weight it added to the Viking 1. I kept remembering how my first Viking 1 was so easy to move around with its aluminum cabinet and how nice and clean its front panel looked without a dozen extra screws. In 2025, the exact parts were given to me that allowed returning the "TC" Viking 1 chassis back to having its original aluminum cabinet and its original front panel.

The Front Panel - I'm going to use Testor's model paint. I'll have to mix and match for the missing gray paint and the missing dark brown paint. The white nomenclature is all in good shape except "METER" which is 99% gone. I have some white dry rub-on transfers that are about the correct size and font,...not exact, but close. But, if the dry-transfers are just not close enough of a match, I'll just repaint the missing brown and leave the nomenclature off completely.

The Meter that's Installed - As long as the Viking 1 is going to have its front panel exchanged, I'm going to check the meter that's currently in the transmitter versus this "parts meter." The meter now in the transmitter will not indicate a consistent level of PA current with the readings sometimes differing as much as 25mA or about a 10% error. Each time the transmitter is keyed, it shows a different level of PA current. Usually, this type of meter problem is due to wear in the suspension bearings. I'll use the meter that tests the best. Also, since the original early Viking 1 didn't have the meter shield, that will not be used in this rebuild.

PARTS METER TEST: I tested the "parts" meter and found that it is a 5mA FS movement. Since the plate current scale is 500mA FS, the linearity is very easy to check. 100mA error is 1%, 250mA error is 1.5% and FS 500mA is 3% error. This is actually normal for an analog meter. I pulsed the DC test voltage for 300mA reading and it repeatedly showed 300mA. This meter movement is going to be used but I'll have to install it into the other meter's case since this meter's case has a severe crack in the bakelite housing.

Once I finished with the rubber mallet, I looked over the cabinet and it really wasn't fitting together very well. Luckily, the cabinet can easily be taken apart and that results in several flat (more or less) pieces that can easily be accurately straightened. Using blocks of hardwood and a body hammer, I was able to straighten all of various bends, crinkles and other defects in the aluminum. I also thoroughly cleaned all of the cabinet panels with Glass Plus. Then I reassembled the cabinet. It now set on the bench nice and flat and it looked square. I tried the old style front panel for fit with no problems. The "before" condition of the front panel and the condition of the "straightened cabinet" can be seen in the photo to the right. Painting is next.

Cabinet Paint - Artist's Acrylic paint allows color-matching exactly. I used the inside of the top lid since that paint was in perfect condition. The base color is Burnt Umber, which is a dark brown,...but not dark enough for the Viking 1. I had to add Mars Black to get a match to the correct Viking 1 brown color. Burnt Umber does have a slight reddish-orange tint, so only black was needed to get a good match.

I first had to "touch-up" all of the areas that were missing paint. As can be seen in the photo to the right, there was A LOT of missing paint. Once all of the bare metal was painted and left to dry overnight, then I could proceed with the "color wash." This process thins the paint mix to the consistency of thin oil. This is then "sponged" on to the cabinet paint. The sponge is used to "dab" the thinned paint onto the cabinet to add some texture and to reduce the "stripes" that could happen. The first coat has to dry several hours, overnight is better. A second coat is usually necessary and does produce a better end result. While this type of "touch-up" paint job isn't any type of substitute for a correct-color, actual wrinkle-finish paint restoration, it's pretty easy to do and the end-result is the correct color that looks good from a distance (about 4 feet or more away.) Close-up examination will show all of the "touch-ups" and minor cabinet defects. But, with other equipment beside the Viking 1 and the VFO set-up on top, the "touch-ups" look great. 

The Viking 1's Original Aluminum Cabinet and Original Early Style Panel
 after cabinet bodywork was completed but before painting. Front panel hasn't been "touched-up."

With all of the knobs, the meter and the bezel mounted, the touch-up job is pretty good. Certainly apparent if you know about the work that was done but probably not noticeable unless pointed out.

Meter Problems - Dec 29, 2025- I thought I was going to be using the same meter that had been in the Viking 1 before. I tested it thoroughly and there's nothing wrong with the suspension and the meter is fairly accurate. I suspect the problem is probably in the meter switch soldering or the shunts. The wires are just pushed through the terminals and soldered. With solid wire, there might be a cracked solder joint or maybe one of the solid wires is cracked. Eventually, I ended up replacing this meter with the one that I had tested (that had the cracked case) because the latter meter was more linear over all. 

Plate Tuning Bezel, Index and Rotating Scale Problems - Probably because the transmitter Pi-network was built using two different sets of parts, nothing really fits together exactly. I actually find that the bezel fits better and mates with the scales better if it's mounted upside down. Not really noticeable unless it's pointed out.

Since the meter actually measures a very low current across a low resistance shunt, if that shunt has a higher resistance than expected, more current flows through the meter resulting in a higher reading on the meter scale. It might be poor soldering, it could be the shunts are too long (they are made of short lengths of coiled wire) or maybe the chassis ground isn't very conductive.

The problem ended up being poor soldering of the shunts for both the Plate I and the Modulator I. Also, the ground soldering on the shunts was very poor and the solder lug for the shunt chassis ground wasn't tighten. I ended up removing the shunts and moving the chassis-ground connection closer to the shunts location that only required about a 1" wire to chassis. The shunt connections were cleaned and then the shunts soldered back in place. I now had 110 watts RF Carrier output power with 275mA of Plate I and the Drive was at 12mA grid current with the Drive control set on about 4. This all looked correct. I switched to MOD to measure the idling modulator Plate I and it was measuring about 30mA,...it should be between 60mA and 80mA. I readjusted the divider resistor to slightly increase the screen voltage and that got the modulator Plate I up to 70mA with +350vdc screen voltage, which is correct. I had to redo the solder on the divider resistor terminals also. In fact, the entire transmitter looks like it was assembled poorly with wire leads just pushed through terminals and then soldered. No wire wraps at all. The soldering looks like really cheap solder was used. Certainly not Kester 60/40 SnPb,...maybe just a soldering iron that was too cold. Fortunately, by now, with all of the rework that's happened over the past 17 years, most of the solder joints have been corrected,...hopefully.

Another Dilemma - So, what's correct,...the Johnson schematic, the Johnson manual or the RCA tube manual? None of these documents agree on expected voltages or currents. I had to slightly change the resistor values in the bias network to have -74vdc which is the bias rectifier output and can't be easily changed. Then I set the modulator grid bias for -30vdc which is the tube manual spec if the plate voltage is +600vdc and the screen voltage is +290vdc. I had to set the 20K divider quite different from where it had been set since the screen voltage had been running about +380vdc and +300vdc is maximum spec for the 807s. The bias voltage for the buffer tube is -17vdc which seems to be fine. The Viking 1 manual says to adjust the 20K divider for 70mA to 90mA of modulator idle current but that would require the screen voltage set to about +400vdc! With ALL of the 807 voltages very close to the RCA tube manual specs, I get 40mA of idle current. That is, with +290vdc screen voltage, +610vdc plate voltage and -30vdc grid bias voltage. I double-checked the idle current by pulling one end of the shunt and inserting a Triplett 630 to measure the current,...it measured 35mA, so the Viking 1 panel meter is fairly close. Running into the Collinear Array at a 1:1 match, I have 275mA of plate current with 12mA of grid drive. The power output is 110 watts on 3.974mc. The audio has never sounded better. My thought is that Johnson was providing a kit and had to make sure assembly didn't require in-depth measurements or hand-selecting certain parts,...even though the expected builders would have been hams. 

Viking 1 and National HRO-7S - 2026 Station

I just got this station set up on Jan 1, 2026. The photo to the right shows the set up. The Viking 1 looks nice, not perfect, but certainly the front panel turned out a lot better than I expected. The "touch-up" paint I color-matched is virtually undetectable. The gray mix actually has to be a shade lighter than the match because the paint dries slightly darker. This mix turned out excellent. The brown mix was much easier to match because it's a dark color. The "METER" dry-transfer nomenclature is difficult to notice at the distance this photo was taken. The size is just slightly larger but the font isn't too close. Still the "METER" difference is hardly noticeable. The cabinet is an excellent match for the brown color but the acrylic paint wash texture is only fair. The body work got the cabinet shape better than it had been but aluminum is pretty unforgiving for knocking-out dents, as can be seen in the photo. But, the difference in weight is the important factor in favor of the aluminum cabinets. The Viking 1 installed in the aluminum cabinet only weighs about 55 pounds and that made it easy to install on the desk riser where it now sets.

The receiver is the 1947 National HRO-7S. The "S" suffix is for Special which designates the black wrinkle finish paint with the smooth finish nomenclature panels. These versions were made to go with the HRO-7R receivers that came stock with a black wrinkle finish panel. Typically, the "R" rack-mount version was used commercially and was typically for use at Airports. The table HRO-7S in black wrinkle was for Airport use where a table version of the receiver was required. The matching coil sets are in the wooden holder setting on the Viking 1. The loudspeaker is a black wrinkle finish version of the standard 8" HRO speaker from National. The HRO-7S is very rare with only a few examples having been discovered. The stock HRO-7T is a silvery-gray color.

National HRO-7S Receiver with the Johnson Viking 1 Transmitter

Johnson-Viking Ranger

The Viking Ranger was a 75 watt CW or 65 watt AM exciter-transmitter that covered 160M to 10M and had a built-in VFO that was very stable. The audio section featured a special modulation transformer with a winding that was used for negative feedback resulting in excellent quality audio. The PA tube is a single 6146 and the modulator tubes are a pair of 1614 tubes (like a 20W plate dissipation 6L6.) The Ranger had all of the outputs accessible to interface with the Desk KW for sufficient drive for full output from the Desk KW. Better performance between the Ranger output and the Desk KW input requirements would require using a small -3db attenuator (about 30W dissipation) to allow better adjustment of the Ranger's drive and output circuits. Rangers were very popular as a stand-alone transmitter also, especially for Novices since the power limit then was 75W on CW only, crystal control (you got to use the VFO after you up-graded your license.) Still today, the Ranger is a popular transmitter for vintage AM because of its excellent audio and "bullet-proof" construction. Over 14,000 Rangers were built. They were available as either a kit or fully assembled. Prices were $293 assembled or $214.50 as a kit. The later version was designated as the Ranger II and featured different modulator tubes, a two-tone gray paint job and dropping the 11M coverage in favor of 6M coverage.

The very first transmitter I owned was a $75 Viking Ranger. I bought it when I got my Novice license in March 1970. At the time, Novices were limited to 75 watts input power, Crystal Control and CW only on 80M, 40M and 15M. Voice was allowed on 2M. I used the Ranger for six months, the length of time I had my Novice license until I upgraded to General Class. I traded the Ranger in on a Hallicrafters HT-37 that had a very oxidized chassis and certainly didn't work all that well. By December 1970, I had purchased a used Collins KWS-1 transmitter (that I still have.)

The Ranger shown belongs to Sharon KK7EI. When she became a Novice in 1975, I bought the Ranger for her from Bob Meckley (I don't remember his callsign,) who was the photographer at Bentley Nevada Corporation in Minden, Nevada (where I worked then.) I paid Bob $50 for the Ranger and it was operational and in good physical condition. Sharon's call then was WN7AZE. Novice Class at that time was still 75 watts maximum power input but the license was good for two years (non-renewable) and you could use a VFO, CW only on 80M, 40M and 15M. Sharon let that license lapse but got another Novice when we had the radio museum (in the 1990s.) She did the 13WPM CW test at the Novice exam (just to show-off, I guess) and then upgraded a month later to General doing the written exam then. She upgraded to Advanced with that written test the next month. The call KK7EI was the FCC-issued call she was given at that time and which she still holds.

The Ranger was a factory assembled one. You can tell because the tube sockets are riveted to the chassis while the kit versions will have tube sockets that are mounted with screws and nuts. The Ranger worked very well except for an intermittent problem. The trouble was with the 6AX5GT rectifier tube socket. It seemed someone had glued the loose base on the 6AX5GT tube and that glue had run down into the chassis-mounted tube socket. I cleaned the socket several times but it was always getting glue that was somehow caught inside the socket somewhere to cause intermittent problems. I finally had to replace the socket which was unfortunate since now that tube socket is mounted with screws and nuts instead of rivets. Of course, I had replaced the glued 6AX5GT long before. Other upgrades were replacing the capacitors, not with different values, just new capacitors. The regulator load resistor was changed to a 10 watt resistor but remained located in the VFO compartment. 

I used the Ranger for several years as the exciter for the Johnson Desk KW. That combo was on the Saturday morning 3870 AM net running 275 watts in the "Tune Mode." The Ranger's excellent audio is a result of its special modulation transformer that has a specific winding for negative feedback. I didn't have an attenuator between the Ranger's 50 watt RF output and the Johnson Desk KW that only requires about 30 watts of drive. Instead, I reduced the drive level on the Ranger until I had about 12mA of grid current for the Desk KW amplifier tubes. This really isn't the best way to drive the Desk KW. A -3db attenuator between the Ranger and the Desk KW would allow the Ranger to operate closer to specifications.  >>>

>>>   With the closing of the Western Historic Radio Museum in 2012 and the subsequent move to Dayton, Nevada, I disassembled the station in Virginia City. Since the move, the Ranger was used one time and that was with a different Viking Desk KW to help out Ham and Hi Fi try to get a Desk KW operational and ready to sell. The Desk KW had belonged to NU6AM who had used it for years. It was functioning fine until it was disassembled to allow it to be moved from Los Altos, CA up to Sparks, NV. H&HF reassembled the Desk KW but didn't have any way to drive it. I brought over my Ranger and the interconnecting cables to drive their Desk KW into their dummy load. Although it would power up the filaments any attempt at "Tune Mode" transmit (+1250vdc plate voltage) would blow fuses. In the last attempt more than just the fuse blew,...my Ranger's function switch arced-over. I suspect there was a "compatibility problem" with the H&HF Desk KW having something different in the wiring of the interface cable. I didn't really have the time or even the opportunity to investigate that possibility. I know my Ranger and cables and my Desk KW were wired exactly per the manual but I don't know about the H&HF desk (and they didn't get the NU6AM Ranger or the interconnect cable in their purchase, just the Desk KW.) H&HF gave me a "junker" Ranger chassis that was stripped but still had the Function switch, so I could repair my Ranger, which I did. I've used it a couple of times since then, whenever I needed about a 50 watt RF source for testing, but it hasn't really been "on the air" since 2012.

E. F. Johnson Company -  Viking Desk Kilowatt found at the University of Nevada-Reno

The Desk KW and the Ranger
with the KW Matchbox

The set-up was in the Western Historic Radio Museum located in
Virginia City, Nevada. ca: 2009

The Viking Desk KW was introduced in 1955 and was available up to around 1964. The "Desk" is a high power RF amplifier with a high power audio modulator, power supplies and all of the control equipment built into a fairly compact "pedestal." The Desk KW features continuous tuning from 3.5 to 30mc. The PA operates Class C and has two output levels, low power for tuning up or operation at 250 watts carrier output or high power for 1KW input power. Plate voltage is either 1300vdc or 2600vdc depending on the output power selection. Originally, 872 MV rectifiers were used for the Plate supply but many amateurs have replaced these with 4B32 Xenon rectifiers or with Solid State rectifiers. An external relay (operated by the exciter) must be used with the Desk KW for linear operation for SSB to allow switching between "Blocking Bias" and "Operating Bias." The PA requires 30 watts of drive for full output and the modulator requires 15W for full audio drive on AM. The PA tubes are a pair of 4-250A tubes (4-400 on later Desks) modulated by a pair of 810 tubes. The entire unit is on guides and rollers and is easily accessed for testing or adjustments. The desk itself was a $123.50 option that could be bolted to the side of the pedestal for complete operating station desk with room for the exciter and the station receiver. The Desk KW sold $1595 without the desk. The Desk KW shown is number 280 of the 402 built.

The Tip and Acquisition - The Viking Desk KW shown was partially disassembled and was going to be "parted out" by the University of Nevada-Reno (in 1997.) A friend of mine, N7PSA Craig Hundley (now W4YBS out of Alabama,...I guess Craig liked my call) worked at UNR's Seismology Lab back then and happened to see the Desk KW (disassembled) in the hall on the second floor of the Electronics Building. His phone call to me was something like,...

"Are you interested in a Johnson Desk KW? Well you better get over here, they're throwing one away!"

I left for Reno immediately. When I got to the UNR Electronics Building, I found the Desk KW on the second floor. It had been taken apart and looking like it was destined for destruction. I asked around and finally found that the UNR Wolf Pack Ham Club had gotten the Desk KW as a donation and they weren't sure what to do with it since they couldn't move it to the third floor where their ham club station was. They had disassembled it to see if they could move it up the narrow stairway to the third floor "in pieces" but, they really didn't know what they would do with it, even if they managed to get all of the pieces to the third floor. Since moving it seemed futile, they were actually considering "parting it out." In talking with the president of the UNR Ham Club, I found out the ham club actually wanted other more modern equipment that they actually needed so I made a deal with them of $250 cash for the Desk KW pieces, which was the cost of the equipment they wanted to buy. Luckily, there was an elevator from the second floor of the Electronics Building down to the loading dock. It took three of us (Craig had joined us by then) to load the main chassis into the pick-up (a '66 El Camino) that I brought. The desk and the rest of the parts also fit into the back of the pickup bed. Then the Desk KW was on its way up to Virginia City. The KW Matchbox was with the Desk KW and was included in the deal.

When I got back to Virginia City, I had to remove the plate transformer, the modulation transformer and the filter reactor to get the chassis light-weight enough that I could move it by myself. After a little inventory of parts I found the wooden frame trim piece was missing and so was the metal cover for the amplifier. I went back to UNR the next day to search around the third floor ham shack and there I found the wooden frame and the metal cover plus a few other little parts that went with the Desk KW. During UNR's disassembly I guess they moved a few things to the third floor but left the heavy pieces in the hall on the second floor.

The Rebuild - The former owner of this Desk KW had used it on SSB. He was driving it with a Hallicrafters HT-37 (I know,...unbelievable) and the bias set up was highly modified. Even different regulator tubes were installed in the regulator chassis. Also, there were changes in the insulated potentiometer board. Luckily, the manual provided all of the information I needed to return this part of the Desk KW back to original. Johnson liked to use solid TC hook-up wire in their harnesses. With the regulator chassis removal (a couple of times, at least) and other movement of the harness, two of the TC wires broke and had to be repaired. This seems to be a common occurrence when doing much under-chassis work on any Viking transmitter. The chassis is a "double-decker" with both bed plates being nickel-plated. These had a slight coating of oxidation from where the Desk KW had spent most of its existence (off the west coast probably.) This was easily removed with WD-40 and 0000SW. The former owner had punched several holes on the right side panel of the pedestal to have access to the bias pots. These holes were left since there wasn't much that could be done and they weren't really obvious. I pulled everything apart to check all components. I found the finals were RCA 6156 tubes, an equivalent of the 4-250A. The small fan inside the amplifier was okay but the large "push-pull" fans were worn-out. New open frame motors exactly like the originals were available. These fans are not balanced very well and to compensate for the rotor imbalance, the original metal fan blades have to be statically balanced and slightly tweaked until the fan runs smoothly. These fan motors have felts that should be saturated with light-weight machine oil every couple of years. The lower fan pushes air into the pedestal and the upper fan pulls the warm air out of the pedestal. There are three Potter-Brumfield relays at the lower front area of the Desk KW chassis that control all of the operation functions. The contacts on these relays were in poor condition but were easily cleaned up with 400grit AlOx paper. These contacts take a beating and need to be cleaned at least once a year for reliable operation.   

Since I had set-up the ham shack as part of the Western Historic Radio Museum, this area had been part of the basement of the Parish House. Sometime in the past, 240vac was installed in the basement for a washer-dryer combo. I rewired the entire ham shack to have all AC wiring in conduit and to have an actual switchbox and fuses on the 240vac line in. The 240vac outlet was a dryer type 50A outlet. I used a dryer AC power cable for the connection to the Desk KW. The orientation of the AC plug from the Viking Ranger as plugged into the AC outlet on the Desk KW is very important. In one orientation all relays operate from the Ranger's function switch but if plugged in with the opposite orientation, none of the relays function. I painted the top of the Ranger's AC plug red so I would always know the proper orientation.

The RF output of the Desk KW ran to a commercial Harrison Dummy Load that was rated at 5KW. The first test was low voltages only and no problems were encountered. Next was high voltage in the "Tune mode" which actually runs the high voltage at about +1250vdc rather than the full +2500vdc. The Ranger should provide about 12mA of grid drive. This test had the Desk KW running at about 275 watts output power. I switched to "Operate" and fine tuned everything, the power output was around 700 watts. That was the only time that I operated the Desk KW at full power but it seemed to handle it just fine.

The desk option generally is mounted to the right side of the pedestal. There are several bolts that provide the attachment. There's also a "modesty shield" in the footwell area. The pedestal has four leveling type metal feet and the desk attachment has two metal leveling feet. The Desk KW would be a lot easier to move if casters were installed but the museum shack has a linoleum floor so "sliding" is fairly easy (not now, the Dayton shop floor is concrete.)

I have the KW Matchbox on the pedestal and then the Ranger on top of the Matchbox. The metal cover for the KW panel stows in a pocket on the right side of the amp. There's also a cover that slides up and down for the lower panel with the plate voltmeter, mode switch, pilot lamps and fuses. When operating the Desk KW, the T-R relay has to have a slightly delay added using a RC network to allow about a half of a second hold when going to receive. This assures that the antenna load remains on the PA output until it has discharged.

I use 6156 tubes in the final PA because these RCA versions of the Eimac 4-250A are usually cheaper but have the same specs. The only difference is the 6156 doesn't have the metal base shroud to direct air flow around the tube. Since I only run the Desk KW in the "Tune Mode" it is never really running more than at just "an idle" and therefore the 6156s work fine. I also don't use the original 872 MV rectifier tubes but use 4B32 Xenon rectifier tubes.

photo above: Output Network with over-sized roller inductor and large air variable capacitor. Photo right: The finals - a pair of 6156 tubes which are the RCA equivalents of Eimac 4-250A tubes - they look a little darkened but worked fine in the "Tune Mode."

photo above: The modulator section showing the pair of 810 tubes and the huge modulation transformer. The lower deck can be seen and the Potter-Brumfield relays and the VR tube regulator chassis are visible. Also, note the replacement open frame motor for the fan. It's the original fan blade through.

Tune Mode versus Full Power - Of course, the Desk KW is really capable of about double what the T-368 can do, if it's operated at its full power of 1KW input. I did that into a dummy load years ago and I got about 700 watts output. But, due to the FCC 1991 rule change regarding AM operation, 1KW input power isn't the legal limit anymore. Now it's 1500 watts PEP output power into a 50Z load as measured with a Bird Watt Meter (didn't you ever wonder why there are so many Bird Watt Meters are around? With its multitude of tuning slugs and difficult to read meter, it's nice to have Federal legislation help sell your over-priced product and increase your business that way.) Although it sounds like more power (and it was for SSB) it's really less AM power because double sideband AM also adds the audio power as it modulates the carrier wave and the carrier power is usually measured in RMS, not peak-to-peak. Rule of thumb is PEP W ÷ 4 = Carrier power for AM with no modulation. So, 1500/4 = 375W of carrier power. But, the varying nature of the human voice only achieves 100% modulation once in a while. Most voice modulation levels are far less than 100% and, therefore, most of the time even with 700 watts RMS output, the actual PEP output rarely approaches 1500 watts PEP.

When I get started resurrecting the Desk KW, I'm probably going to replace the 6156 tubes with 4-250A Eimac tubes. I was never very confident in the 6156 tubes and if they were running at full power, I don't think they would last very long.

Using a Proper -3db Attenuator - Another thing, when the Desk KW is back together, I now have a very nice 50Ω -3db attenuator that would result in about 25W of drive power from the Ranger to the Desk KW. That would have the Ranger and the Desk KW operating exactly as the manual indicates. Something I didn't do when I used to operate the Ranger and the Desk KW. By reducing just the Drive on the Ranger, the 6146 wasn't operating correctly and I seemed to go thorough 6146 tubes rather quickly. I think the Ranger's PA will appreciate the use of the -3db attenuator.

Other Full Power Thoughts - I know of a couple of hams that run their Desk KWs at full power these days. With the advent of HDTV moving TV-BC up to the microwaves, harmonic TVI is a thing of the past. Also, I don't have any nearby neighbors here in Dayton Valley that could experience fundamental overloading. And, as to running 700 watts carrier output on AM,...I remember 20 years ago that W6HDU (SK) in Alameda, CA would run a 5KW Western Electric BC-AM transmitter at full power output on 3870kc but he would tell everyone he was running a Collins 32V-3! And, when one thinks about it,...going from 365W carrier output to 700W carrier output is slightly less than a +3db increase. Would that sound like an increase of one half of a S-unit at the reception end? Or, from S9+10db to S9+13db? Hmmmm. 

More to come if this project can ever get started,...

Johnson-Viking KW Matchbox

The Viking Match Box was a heavy duty, balanced antenna coupler that was link coupled, used bandswitching and had two split-stator variable capacitors that allowed matching various kinds of antenna loads to a transmitter. The Match Box was specifically designed for balanced antennas but could also match coax fed loads or end fed wires. The SWR bridge required an external Directional Coupler to function but the Match Box was available without the SWR bridge option in which case there is no meter installed. A built-in antenna relay is included inside the box with access via an external terminal strip mounted on the rear of the unit. Additionally, there was a terminal provided so the end-user could install a small air-dux type coil inside the unit to act as the RF monitor pick-up.

This KW Matchbox came with the Desk KW that I got from UNR. I suppose that the two were together since they were new. The KW Matchbox worked okay but I suspected that something wasn't exactly correct inside because it seemed to have trouble with matching some transmitters to a standard 135' CF open feedline dipole. When taken out of the cabinet, I noticed that the inductor showed signs of multiple soldering and unsoldering of the link taps. One link tap is for the 300Z ohm to the "Receiver" connection through the internal T-R relay. The other link should have been set for around 50Z for the transmitter. I could see evidence of where the 50Z link had originally been connected, so I moved that non-original connection back to the original position on the link. There were a few other minor things that needed to be put back to original and then the Matchbox was put back into the cabinet. After the changes, now the Matchbox loaded every transmitter I tried, matching the transmitter output network to the 135' CF dipole antenna.

One slight change I've made is to move the input wire to the relay terminal to the adjacent terminal. This bypasses the antenna relay. If it isn't done, the antenna relay will be in the "receive" position (there is a separate set of terminals for the receiver's antenna connection to the tuner) unless the relay coil is energized with 115vac. I didn't plan on using the internal relay so this easy and easily reversible change keeps the tuner always in the "transmit" mode without the necessity of providing 115vac to the relay. I've been using this Viking Matchbox almost continuously ever since I got it. It has been very useful and matches almost any balanced antenna to almost any transmitter. I also have the smaller version Matchbox that's rated for 275W. This is a pretty good version that works most of the time. I find that the KW Matchbox seems to be easier to adjust and it has a wider impedance range than the 275W version.

I'm currently using the Viking KW Matchbox with the 2 Element Collinear Array antenna in the upstairs ham shack.

NOTE: Dec 26, 2024 - Another Viking KW Matchbox was obtained in a trade. This one was very dirty and had been very slightly modified. Unfortunately the mod added another ceramic insulator that paralleled the coax input (probably to run an end-fed wire antenna.) This insulator was removed and the hole covered with a Cinch plug. Lots of cleaning and adjusting with the end result that this new KW Matchbox is operating almost exactly like my old one. I've removed the Nye-Viking MBV-A tuner from the shop antenna and now have Viking KW Matchboxes for both the upstairs ham stations (working the 2-Element Collinear Array) and the ham stations in the shop (working the 130' tuned dipole.)

NOTE: On the Nye-Viking MBV-A tuner,...these tuners are merely "high power rated" Pi-Networks that have a trifilar-wound balun that enables an unbalanced network to work with balanced loads. The losses in the Nye-Viking balun are legend. It might be a good tuner to work with an unbalanced to unbalanced load but it's not good for anything that goes through the balun. The losses can even be noticed in the receive mode. At any rate, the chance to replace the Nye-Viking came and I "went for it."

Photo above shows the Navigator with the stock iron vane meter and stock "Grid-Plate" slide-switch.    a 2004 photo

E. F. Johnson Company - Viking Navigator
 

The E. F. Johnson Company has been in business since the 1920s and is still active in the component business. During the post-WWII period up to about 1974, Johnson was a major builder of ham transmitters, ham accessories and other communications equipment. The Viking Navigator was introduced in 1957 and was available for about four years. It could be purchased as either a kit or fully assembled. The transmitter-exciter is only 40 watts input power with a little over 25 watts of output power on CW only. Coverage is 160 meters through 10 meters. The PA tube is a 6146 with about 400vdc on the plate.

The Navigator featured a fairly standard Johnson VFO, although regulation is somewhat different than their standard VFO as found on the Ranger, for example. Also, a keyer tube is used which provides adjustability of the CW keyed waveform shape. The keyer circuit is also quite different from the Ranger. The "Iron Vane" meter is a source of many problems and its accuracy is always in question. The slide switch that selects Grid or Plate current is also somewhat problematic. Many times, Navigators are found with these two parts replaced. A great QRP CW transmitter that is very small and light weight. Original selling price was $199.50 factory-wired and $149.50 as a kit. Only 840 Navigator transmitters were produced. The Navigator was donated to the museum by my old friend, Gerald Morris K6QY (SK) in 2004. Gerald's QTH was in Oakland, CA. His two-story, 1910 Craftsman-style house was in fabulous condition with loads of period woodwork inside. The house was located on a side street directly across from Kaiser Hospital in downtown Oakland.

The Navigator was non-functional when it was given to me. Gerald had purchased it at a Foothill College Ham Swap Meet (in Los Altos, California) from someone cleaning out a load of gear who wasn't the least bit interested in what they were selling, which was lucky for Gerald. The purchase price for the Navigator,...$20. As can be seen in the photo to the left, it was in excellent original condition. Gerald used it for quite a while until it quit working. I'm sure Gerald knew that the filter choke had burned up but he just didn't want to work on the Navigator, so it was given to me. I went though all of my filter chokes and I found one that was exactly the same type as the original. That was installed and the Navigator came to life again. As I used it, I began to notice that the iron vane meter was constantly "banging" against the needle stops. This couldn't be the way Johnson designed it,...or could it?

I can't stress the point strongly enough that the original Johnson Navigator "iron vane" meter is a real "piece of junk" and is not really repairable if a problem develops in an original unit (who'd want to fix it anyway.) The plastic cover is glued all around the perimeter of the meter scale backing plate and any attempt to cut away the glue cracks or breaks the plastic cover. Apparently, if a problem developed in the meter, Johnson wanted you to replace the entire meter instead of repairing it. That might have been okay in the late-1950s but now, 65+ years later, I don't think Johnson still stocks Navigator meters. Johnson's decision to install a $2 meter into a $200 (factory-wired price) transmitter was certainly profit-motivated. However, it is possible to fit a Johnson Ranger meter into the Navigator and with some minor adjustments to the shunt(s) it becomes an accurate and useable instrument (which the original Navigator meter never was.) Plus the Ranger meter is illuminated, it has the "Viking Head" logo and it even has "E. F. Johnson Co." on the meter scale. Johnson certainly would have wanted to install the Ranger meter but the price of the already expensive Navigator would have been even more. So, if you want the never-produced "Deluxe" version of the Navigator, here's how it's accomplished (after you've found a Viking Ranger meter, of course.)
 

E. F. Johnson's  Viking Navigator "DeLuxe"

I really had to think about this modification for a long time. It went against everything I advocated about restorations. The Navigator was a fun little transmitter but the iron-vane meter literally ruined the pleasure of operating. I knew that a Viking Ranger meter was really what Johnson had "wanted" to put into the Navigators but economics had forced them to install a totally useless "piece of junk" iron-vane meter instead. Every Navigator owner I've talked to feels the same way about the original "Navi-meter" - it's pure junk! Worthless and inaccurate,...an embarrassment to an otherwise nice little transmitter. Although I wasn't actively looking for a Ranger meter, one did show up at Ham and Hi Fi in Sparks, Nevada, making it an easy purchase. Now, a Ranger meter doesn't just drop-into a Navigator and work. It's a moderately complicated modification. Here's the process, with photos, of how to change your plain-old Navigator into a "Navigator DeLuxe." Of course, these aren't "step-by-step" instructions. I'm assuming that if you want to install a Ranger meter into a Navigator, you have the moderate electronic restoration skills and knowledge necessary for the task.

Something Interesting with the Original Meter - I hadn't operated the Viking Navigator since I had moved from Virginia City in 2012. The Navigator had been in storage in the upstairs lab which is a stable environment with no extremes of any sort. In my research before actually performing the Ranger meter installation, I thought I'd test the original iron-vane meter. A measurement of the coil showed no continuity at the terminals. I had run into this problem once before when I first got the Navigator. At that time, loosening the terminal nuts and retightening them got the meter functional. This time, no amount of loosening and tightening helped. The meter coil was somehow disconnected from the terminals. There is no repairing the original meter. It can't be taken apart since the plastic cover is glued to the back and any stress on the plastic results in cracks. Better to leave the original meter in good cosmetic condition albeit non-functional since I was planning on installing the Ranger meter anyway.  >>>

Additionally, the Ranger meter isn't exactly a perfect replacement fit. The original Navigator meter requires a 2" diameter hole while the Ranger meter requires a 2.187" hole. The original Navigator meter was mounted using a bracket that attached to the back of the meter and pushed against the back of the front panel to hold the meter secure. The Ranger meter mounts conventionally using four studs that use 4-40 nuts and washers to secure the meter to the panel. This means some modification to the front panel is necessary. Fortunately, if for some reason the original Navigator meter was to be re-installed, the modified larger clearance hole and the four mounting holes are covered up by the overall size of the original meter.

Originality versus Cool Functionality - Anyone who reads any of my articles knows I'm a serious advocate for strict originality. How could I actually want to modify a rarely encountered transmitter to the point where I'd actually be "cutting and hacking?" It seemed unthinkable! However, that's just how BAD the original Navigator meter is. I would think that the E. F. Johnson decision to use the iron-vane meter was based on keeping costs low so the Navigator would be reasonably priced (it really wasn't.) If Johnson could have put another $15 to $20 into the cost, they would have used the Ranger meter. The Ranger meter is a genuine, contemporary to the Navigator, "Johnson" part and it even has the Viking head on the scale. Additionally, it is an illuminated meter (the original iron vane meter isn't.) So, my argument for performing this modification is "Johnson would have liked to have built the Navigator this way but it would have cost a lot more and sales would have been even less than they already were!"  Maybe Johnson should have offered this version as the "Navigator DeLuxe."  

I did a quick test for the grid current using 10mA FS with R shunt=20/4 or ~ 5 ohms. I installed a 5.1 ohm resistor for the grid current shunt. Although the original meter didn't require a shunt, the Meter switch has an extra unused pin (pin 9) that can be used for a grid current shunt resistor connection into the circuit.

During testing I wanted to double-check the accuracy of the Ranger meter and the shunts. I did this by using an accurate current meter installed directly into the grid circuit. I adjusted the Navigator to show 4mA of grid current. I then connected the Ranger meter which showed 2.5mA. A slightly higher shunt resistance was needed so I installed a 6.8 ohm resistor and this then allowed the Ranger meter to show 4mA. I did the same with the plate current shunt and ended up with 1.0 ohm, 1.2 ohm and 1.5 ohm resistors in parallel, or about 0.27 ohms, for an accurately reading plate current meter.

As to why the actual shunt values were slightly different from the calculated values was probably due to the meter I used to measure the Ranger meter coil resistance. I really needed a digital meter that was capable of measuring "very low ohms" accurately which I didn't have. Also, the actual measured FS current for the meter was 4.5mA and for some reason I used 5.0mA in the calculations. With these two changes my calculations would have been accurate. As it was, I got close and then "trimmed" the values to have the Ranger meter read accurately by comparison with a known accurate current meter.  >>>

Meter Cover Shield Modification - To install the rear meter cover in the Navigator requires a clearance hole be cut in the bottom of the cover. This is necessary because of the proximity of the Grid-Plate slide switch (directly below the meter.) The opening width has to be 1.75" and the depth is 1.125" and this is easily cut using a hack saw and then dressing the edges with a file. If carefully executed, the opening looks stock. Mounting the cover requires an insulating washer on the inside and on the outside of each stud. I used the type of insulating washer that has a molded shoulder that provides insulation of the stud through the hole in the cover. See photo to the right.

Connecting the Meter - Each meter connection is filtered with a choke and bypass capacitor. The 6.3vac to the meter lamp is also through a choke and bypass capacitor. The meter studs have terminal solder lugs and the wires from these connect directly to the Grid-Plate slide switch. The meter lamp choke filter is connected to the 6.3vac dial lamp buss connection. The finished Johnson Ranger meter installation is shown in the photo to the right.

Is this cool or what? The Viking Navigator DeLuxe     a 2016 photo

Panel Mounting Screws - Since the cabinet for the Navigator is made out of aluminum it's pretty easy to strip the threaded holes when mounting the Navigator chassis and panel into the cabinet. But, since the cabinet is aluminum is fairly easy to recondition the threaded holes to have enough material to allow gentle tightening of the panel screws. The holes can be deformed using a tool to compress the hole edge material  The compression will slightly reduce the size of the hole. A small vise grip type of tool can usually deform the aluminum enough. Then a 6-32 tap can "chase" the threads or self-tapping screws can be installed. In either case, don't over-torque the screws, just barely tight will work fine. I'm going to replace those Philips head screws with slotted screw heads. They were installed when I got the Navigator from K6QY. UPDATE: Apr 27, 2024,...I dug the Navigator Deluxe out of storage and, to my surprise, I had already replaced the Philips head screws with slotted screws. Don't know when I did that but I guess that means another photograph will be required. New photo below,...

Photo above-left shows the Johnson Viking Ranger meter installed. The top scale is 0 to 200mA and used for plate current. The 0-5-10 middle scale is used for 0 to 10mA grid current. The Viking Ranger meter has the perfect proportions, the correct matching shape and color, it's illuminated so the Viking's head shows up really well, even "E. F. Johnson Co." is on the meter scale. I'm sure ol' Edgar Johnson would have approved of upgrading the original Johnson Viking Navigator to the Navigator Deluxe.

UPDATE: Apr 27, 2024 - I took a new photo of the Viking Navigator Deluxe showing that the Philips head screws are gone and proper slotted pan head screws have been installed. I don't know when I did this,...I just discovered it today when I got the Nav-D-Lux out of storage.

It's been several years since I've operated the Nav-D-Lux. I'm going to return this little transmitter to the bench for a check-out. I know that I checked the general operation after replacing the burned up choke. The grid drive was always running too high when the Exciter was adjusted to resonance or peak. I used to reduce the drive by detuning the Exciter. I want to check the value of the resistors which I know I didn't do back in 2004 or in 2016. Also, the voltage levels need to be confirmed. Initially, the repair of the Nav-D-Lux was accomplished up in Virginia City where the AC line voltage was 115vac. Here in Dayton the AC line is usually about 122vac. So I'll have to run an AC line bucking transformer with the Nav-D-Lux for 115vac. Although, even in Virginia City, the grid drive was too high, so there certainly is something slightly off in the Nav-D-Lux circuitry. 

The Viking Navigator Deluxe - a 2024 photo

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