The Johnson Viking Ranger
by Greg Latta, AA8V


Rear View Of The Ranger

Johnson Viking Ranger Pages:
 Johnson Viking Ranger - Main Page and Exterior Photos  Alignment
 Interior Photos of the Transmitter  Modifications
 Restoration  Schematic Diagrams and Circuit Descriptions
 Typical Operating Conditions  Manuals and Advertisements

Important Safety Note: Working on or testing equipment such as the Viking Ranger is extremely dangerous since very high voltages are present when the equipment is turned on, and may even be present when the equipment is turned off and unplugged. If at all possible, do all work with the equipment off and unplugged and be sure that the capacitors are properly discharged before working on the equipment. The operator assumes all risk and liability in such matters! Do not work on this type of equipment unless you are experienced with working around very high voltages!


Scroll Down or Select A Link Below:
 Line Cord and Fuse Holder Replacement
 Push To Talk Jack
 Replacement Of Vacuum Tube Rectifiers With Silicon Rectifiers
 Modulator Tube Replacement
 External VFO Input
 Speech Amplifier Capacitor C52 Replacement
 Ordering Replacement Parts
 Links To Some Currently Available Parts For The Johnson Ranger
 Modifications Not Recommended

The internet is full of modifications to "improve" the Johnson Viking Ranger. Many of these are pure bunk. It amazes me when someone claims to "restore" a Ranger by tearing out the original modulator circuit and putting in a completely different circuit. This isn't rebuilding the Ranger, it is perverting the Ranger!

The original engineers did a great job in designing the Ranger. As a result, very few modifications are needed or recommended. Remember, the Ranger is now an antique. Modifying the Ranger to "improve" it can seriously ruin the resale value of the transmitter. You are only the temporary steward of your Ranger. It will someday pass on to someone else. Please leave something to pass on. Whatever changes are made, they should be reversible to the extent possible.

Line Cord And Fuse Holder Replacement:
Though I recommend against many modifications, this is one that should be done. Operator safety demands that the original line cord and fuse holder be replaced by a modern 3-wire grounded cord and a chassis mounted fuse holder. Aside from operator safety, the line filter on the Ranger is such that if the chassis is not grounded through the antenna connection or a separate ground connection, as much as 60V AC can be present on the chassis relative to ground. This can give you a slight shock when connecting the antenna, but worse yet it can blow out a solid state component, such as an external VFO, when it is connected to the Ranger!

The Ranger draws less than 5A when in operation, so an 18/3 or larger line cord is fine. The only disadvantage to larger line cords is that they can be very stiff and may require enlargement of the original line cord hole on the Ranger. If you must enlarge the line cord hole, be extremely careful when drilling it out! It very easy to lose control of the drill and damage components. You will also need a strain relief that can fit into the line cord hole on the Ranger. Many times you can get the line cord and strain relief from a discarded piece of equipment.

Mouser Electronics carries line cords, fuse holders, and strain reliefs. The line cord and fuse holder that I used are as follows:

3 Conductor Line Cord:
Mouser Part Number: 562-311007-01

Single fuse holder:
Mouser Part Number: 534-3536

I selected a strain relief from a big assortment that I had in stock. You will have to find one on your own. A photo of the Ranger with the new line cord installed is shown below:

Rear View Showing New Line Cord
Ranger With New Grounded Line Cord Installed
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Finding a location for a fuse holder was difficult because anything mounted on the rear panel must be located in the two rectangular regions that are not covered by the cabinet. No location on the outside of back panel for a hole mounted fuse holder could be found, but it turns out that there is just enough room on the inside of the back panel near the auxiliary connector to squeeze in a molded base fuse holder (with a 5A fuse). Mounting the fuse inside meant that replacing the fuse would require removal of the Ranger from its cabinet, but there was really no other way to mount a fuse.

Very carefully drill a hole for the fuse holder and mount the fuse as shown at top center in the photos below. Code requires that the fuse is wired in series with the hot AC wire, which is the one connected to the narrower blade on the AC line plug. For the cord I purchased, the hot AC lead (narrow plug blade) was brown, the neutral lead (wide plug blade) was blue, and the ground lead was green/yellow. (Your cord may be different). I mounted a solder lug under one foot of the terminal strip holding the four "firecracker" RF chokes, and I soldered the ground lead to that. You can see the connections clearly in the photos below:

Power Entry and Exit
A molded base fuse holder with a 5A fuse can be squeezed in
on the back panel as seen at top center in this photo.
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Push-To-Talk Jack:
Though the Ranger is a great CW rig, the mode where it really shines is on AM. When operating phone, I prefer to operate in push-to-talk (PTT) mode. My D-104 mic was equipped with a PTT switch, and J1, the Ranger mic jack, has a connection for the PTT line from the mic, but it not connected to anything. There are instructions in the Ranger manual for wiring the transmitter internally for PTT, but these extensively modify the Ranger itself, and I recommend against such a modification.

A far better option is the bring the PTT line outside the transmitter and connect it to an external PTT circuit. That way you can change the PTT circuit easily without going into the transmitter, and without making extensive modifications to the transmitter itself. Carefully drill a hole for the RCA jack just to the right of the antenna connector on the back panel. (Don't drill it too far away, or it won't fit through the rectangular cutout in the cabinet). Run a wire from the center of this jack to pin-2 of the mic connector. Keep the wire against the chassis, away from antenna connector and coupling capacitors, and as short as possible. There is a gap under the metal shield around the mic jack that you will be able to fit it through. (You may have to remove the shield to solder the wire to the mic connector). See the photos below:


RCA PTT Connector On Back Panel
A wire (green) is run from pin-2 of the mic connector
(inside shield) to an RCA phono jack mounted on the
back panel, just to the right of the antenna connector.
Click on the image for a larger view.
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Rear View Showing New Line Cord
An external PTT jack (RCA phono jack) is mounted on the
back panel just to the right of the antenna connector.
Click on the image for a larger view.
Click here for a super detailed view.

After the modification, you can connect your external PTT circuit to the PTT jack. The jack in normally open, but shorted to ground when the PTT switch on the mic is pressed.

The easiest way to use the PTT jack is to use it to switch a 12V DC relay off and on. The relay can then key the transmitter, mute the receiver, activate an antenna changeover relay, light an "On The Air" sign, etc. The possibilities are endless.

Replacement Of Vacuum Tube Rectifiers With Silicon Rectifiers:
One of the first things I noticed after restoring my Ranger and putting it on the air was how hot it ran, even in CW mode, when the modulator tubes were disabled. A lot of the heat seemed to becoming from the area of the 5R4 and 6AX5A rectifier tubes. At the time the Ranger was designed, solid state diodes had not yet been perfected, and none were used in the Ranger. I thought it might be a good idea to try replacing the vacuum tube rectifiers with modern solid state silicon diodes. This isn't to reduce the heating of the power transformer, as some people might think, but rather to eliminate the heat produced by the rectifier tubes. The heat from the filaments in the rectifier tubes alone amounts to 10W for the 5R4 and 7.6W for the 6AX5A. That is almost 18W just for the filaments alone, let alone the heat produced by the voltage drop across the tubes. With solid state diodes the heating in the rectifiers would drop to less the approximately 3W.

Replacing the rectifier tubes with solid state diodes would eliminate the heating in the rectifier tubes, but increase heating elsewhere throughout the transmitter due to increased high and low B+ voltages. The only way ultimately tell whether tube or diode rectifiers would work better would be to actually make the change. Fortunately, it is possible to make the change in a completely reversible form, with no permanent modifications to the Ranger. The secret is to mount the diodes in octal tube bases, which can be obtained from Antique Electronic Supply. I found that when the vacuum tube rectifiers were replaced with solid state diodes, the overall heating in the transmitter was noticeably reduced, so I recommend this modification.

To make the modification you will need two octal tube bases and eight 1N4007 diodes. These can both be obtained from Antique Electronic Supply and other suppliers as well. The part numbers from Antique Electronic Supply are:

Octal Tube Base:
Antique Electronic Supply Part Number: P-SP8-476

1N4007 1000V Diode:
Antique Electronic Supply Part Number: P-Q1N4007

For the 6AX5A replacement, use two single diodes and an octal tube socket. Wire one diode from pin 3 to pin 8, with the cathode connected to pin 8. Wire the other diode from pin 5 to pin 8, also with the cathode connected to pin 8. Don't solder pin 8 until both diode leads have been connected to it, and make sure that both are soldered. (The pins are numbered from 1 to 8 clockwise from the key when viewing the socket from the bottom). Label this octal base clearly "6AX5". The octal bases are not interchangeable! Place this into the 6AX5A socket.

For the 5R4 you will need one octal tube base and six diodes. First make two three-diode strings, connected in series from anode to cathode. Keep the connections between the diodes relatively short. I made my strings so the middle diode was horizontal and the outside diodes were vertical. Wire one string from pin 4 to pin 8, again with the cathode end connected to pin 8. Wire the other string from pin 6 to pin 8, also with the cathode end connected to pin 8. Don't solder pin 8 until both diode leads have been connected to it, and make sure that both are soldered. Label this octal base clearly "5R4". The octal bases are not interchangeable! Place this into the 5R4 socket.

Keep the original rectifier tubes in a safe place in case you ever want to go back to them instead of the diodes. You will notice that your Ranger is noticeably cooler after you have replaced the tubes with the solid state rectifiers.

With the diodes in place, the low and high B+ voltages will be higher. This will require that you readjust R35 for proper modulator resting current. You will also be able to get more RF output from the Ranger than before, but I do NOT recommend tuning the Ranger for more output. That isn't the point of replacing the rectifier tubes with diodes. Tuning for more output defeats the point of using the diodes, which is to lower the transmitter temperature. Increasing the output overloads the 6146 final, the modulator section, and the power supplies which are NOT designed for the extra output.

I recommend that you tune and load the Ranger for the following outputs:
In CW Mode - 45W output
In AM Mode - 40W output (160W PEP with maximum modulation)

These outputs correspond very closely with the 75W/CW and 65W/AM inputs recommended by the Johnson Company. Tuning for more output will only give you 1.0dB or 1.5dB more output, which cannot be heard on the air. Don't tune for maximum output. Tune for rated output!

Modulator Tube Replacement:
The Ranger was designed to be used with 1614 vacuum tubes. These are an RF rated version of the 6L6, primarily designed for RF amplifier service. They are electrically identical to the 6L6. Why the designers used them is a mystery to me, since they are being used at audio, not radio, frequencies. If you have 1614 tubes and they seem to be OK, then continue to use them. If however, your 1614 tubes seem to be weak, and need replacement, then there is no need to use actual 1614 tubes which are now very expensive, at about $42 per tube.

A much better choice if you need to replace your 1614 tubes is to replace them with 6L6GC tubes. These are very common in guitar amplifiers, and can be obtained at a local music store. You can get a matched pair of Tung-Sol 6L6GC tubes from Sweetwater Sound. See the link below.

Pair of 6L6GC Modulator Tubes:
Sweetwater Sound Part Number: Tung6L6STRMD

Personally, I am using a pair of Svetlana 6L6GC tubes with great success.

After installing a new set of modulator tubes you will need to readjust R35 for the proper modulator resting current. You may also need to make adjustments to R35 as the new tubes break in.

Glass tubes can cool themselves better than metal tubes, but this by itself isn't a valid reason to replace the 1614 metal tubes with 6L6GC glass tubes. The total heat that comes out will be the same, whether it is a metal or glass tube. It is just that it will be convected away from the metal tubes and radiated away from the glass tubes. Either way the same amount of heat is released into the Ranger cabinet. In other words, don't put in new tubes just because someone told you they will make your Ranger run cooler. That isn't true!

Another falsehood is that certain modulator tubes will make your signal louder. If you keep the input to the 6146 final at the rated 65W, which corresponds to a carrier output of about 40W, then the modulator has more than enough output with any properly operating 1614 or 6L6GC tube. Additional modulator power cannot be utilized and can in fact result in overmodulation. Keep carrier power to the rated value of 40W output and the modulator will always have plenty of output for full modulation.

External VFO Input:
The Ranger transmitter has a built in VFO, but like many transmitters of its time the VFO doesn't meet modern stability requirements. Even after I thoroughly checked and resoldered every component and capacitor in my Ranger's VFO it did not meet my stability requirements. The problem is that trying to stabilize a VFO in the middle of a high temperature environment like that inside the Ranger is very difficult, even with brand new components, and after nearly 60 years of aging the capacitors will cause what was once a stable VFO to drift or jump around in frequency. The best solution is to use an external VFO, and feed the signal in through the crystal socket. The VFO must operate from 1750kHz to 2000kHz for the 160m and 80m bands, and 7000kHz to 7425kHz for all of the other bands. I use a digital keyed VFO that I designed (January 2014 QST Magazine) with an output of 10V peak-to-peak (3.5V RMS), and it has no trouble driving the Ranger on all bands.

The VFO is connected to the XT1 input of the transmitter. This is pins 3 and 5 of the crystal socket. Pin 3 is the ground lead and pin 5 is the hot lead. You must make the connection to pin 5 through a coupling capacitor! The value of the coupling capacitor is not critical. Any value between 0.001uf and 0.01uf at 200VDC will be fine. You can use an old FT-243 crystal holder to make the connection, but a better way is to make an adaptor using a 1" CPVC coupling and 8-pin octal plug. Your local hardware store will have the coupling, and the plug can be purchased from Antique Electronic Supply:

8-Pin Octal Plug:
Antique Electronic Supply Part Number: P-SP8-500

The CPVC coupling has an outer diameter of 1 3/8" and is ideal for this purpose. Sand the 8-pin plug down until it fits very tightly into the coupling as shown in the photos below:

 Coupling and Plug
1" CPVC Coupling And 8-Pin Plug
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 Completed Coil Form
Plug Tightly Fitted Into Coupling
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After installing the 8-pin plug, fit a round plastic or metal cap to the other end of the coupling to hold the RCA phono jack.Wire the center of the jack through the coupling capacitor to pin 5 of the octal plug. Wire the ground lead from the phono jack to pin 3 of the octal plug. Keep the connections as short as possible. I made a small aluminum cap on my lathe and held it in place with set screws. I also added set screws to the octal plug for extra strength. I am sure you can come up with something less fancy on your own. I also shortened the coupling so the jack wouldn't stick too far out of the front panel when plugged into the transmitter. I then wrapped the outer exposed end with black electrical tape for a more attactive look. See the photos below:

VFO Adaptor Without Tape
VFO Input Adaptor Without Black Decorative Tape
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VFO Adaptor With Decorative Tape
VFO Input Adaptor With Black Decorative Tape
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Plug the assembly into the octal crystal socket and set the Crystal/VFO switch to "XT1" to use your external VFO. Remember, your output frequency is either your VFO frequency or an integer multiple thereof, depending on the band. You can see my finished VFO adaptor installed in the photos below:

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Ranger With VFO Adaptor Installed In Crystal Socket
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Speech Amplifier Capacitor C52 Replacement
There are many modifications of the audio system that can be found on the internet and elsewhere. Most of these are wishful thinking, do not do as claimed, or cause instability in the audio system.

Charles Rauch, W8JI, is one ham who really knows his stuff. He has an excellent and extensive web site at On his web site he also has an excellent page covering the various audio modifications to Ranger:

W8JI Ranger/Valiant Audio Modifications Page

One conclusion that comes through loud and clear is that increasing the value of C52, the coupling capacitor between V7A and V7B, the mic preamplifier stages, from 500pf to 0.01uf is about the only change in the audio system of any value. This will bring the low frequencies up by several dB.

If you decide to do this, do not remove the original C52! Remember, you are the steward of an antique, and want to keep changes reversible if possible. Instead of removing C52, solder a new 0.01uf capacitor in parallel with it, making sure that it can be easily removed in the future. This gives an effective capacitance of 0.0105uf, which for all intents and purposes is the same as 0.01uf.. The capacitor should be rated for at least 400V. Below is a capacitor from Mouser Electronics that will work fine:

0.01uf/400V film capacitor:
Mouser Part Number: 75-MKT1813310404

Personally, I have kept my audio section stock, with no modifications. I am getting great audio reports with the original audio system and my D-104 mic, and plan to use external equalization to fine tune my overall sound, if I do anything at all.

Ordering Replacement Parts:
In spite of what many people think, parts and tubes for vintage equipment are still readily available. One obvious source is hamfests, but there are two other companies that I regularly deal with. They have always served me well.

The first company is Mouser Electronics. Mouser is a huge parts supplier. Besides electronic parts they carry tools and hardware, such as #4 to #10 screws, nuts, and lockwashers. They accept small orders and they are happy to deal with a little guy like me. Shipping charges are reasonable, and they have virtually every modern part you could want, including high voltage electrolytic capacitors, big power resistors, etc. They have a good search engine, but they carry so many components that it can take a while to find what you want.

The other supplier is Antique Electronic Supply. They are a much smaller company but specialize in parts for vintage gear and guitar amplifiers, which are usually tube based. They carry tubes, octal plugs, tube bases, tube sockets, and other vintage items.

Remember when replacing electrolytic capacitors in power supplies that capacitors with reasonably higher higher voltage ratings and capacitances are perfectly fine. For other capacitors, such as those in audio and RF circuits, you should use the same value, but a higher voltage rating is fine. For power resistors and pots, a larger power rating is also OK. Keep in mind that modern components are much smaller than they were 50 years ago, which is a big advantage. A 2W resistor today looks like a 1/2W resistor from 50 years ago, so it is perfectly fine, for example, to use a 3W resistor to replace a 1W resistor.

When ordering parts, try to consolidate your order and anticipate parts you might need in the future. If in doubt, get the part anyway, because most parts are relatively inexpensive, and it is the shipping/handling costs that tend to increase the cost of a project. If you wind up not using the part it just goes into your stock. I always make it a point to look around my shop and order some extra parts to keep around, such as 0.001uf or 0.01uf capacitors, screws, nuts, lockwashers, pilot lamps, etc.

A list of links to the parts mentioned above along with others
currently available for the Johnson Ranger can be found here.

Modifications Not Recommended:
The modifications that I recommend against are those that pervert the Ranger into a different piece of equipment (such as total rebuilds of the audio section), ruin the esthetic value or appearance of the transmitter, or otherwise ruin the transmitter's value as an antique. I also recommend against the internal PTT modification in the Ranger manual, because it extensively modifies the Ranger, and it is easier to do the PTT circuit externally. Remember, you are a temporary steward, and some day the transmitter will be passed on to someone else. Make sure you leave something worthy to pass on.

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