I recently won a Johnson Ranger 1 transmitter on Ebay. It looked very nice.
It puts out 40-50 watts but the VFO didn't seem to vary the frequency very much.
On turning the tuning knob the pointer stopped right where it should have.
After many hours deciided to pull the front cover and VFO cage, a very laborious project.
I discovered the flex tuning coupling made of a very thin phenolic was broken clean off.

Are there any replacements available???
I see this is a common problem wth these rigs, what is the typical fix?

73
Al
K2DYH

When I destroyed the phenolic flex in my Ranger, I made a new one with a thin piece of plastic from, I think, a temporary NRA membership card - not as thick as a credit card. I used the smallest hardware I could find to reassemble the coupling but still had to drill the holes out a bit. It's still holding after several years.

Harry, KT4AE
Watkinsville, Georgia

This is a common failure item, particularly in the heavy Valiant where resting the transmitter upside down with its weight on the front panel will cause the coupler to break. Because it uses different size input and output shafts finding a replacement is difficult except out of a parts Johnson unit (Ranger 1 and 2, Valiant 1 and 2, Pacemaker, Navigator, and Viking 500 all use the same coupler).

Like Harry I have repaired a few using plastic. In normal use there is very little stress on the coupling because the capacitor moves freely and the ball reduction drive cannot transmit much torque without slippage anyway. So once repaired it is likely to last a lifetime. Your repair is likely to be sturdier than the original but to protect it consider loosening the coupler screws to allow it to slide on the shaft when you are going to be doing significant work requiring the transmitter to be turned upside down. This is most important when working on the Valiant transmitters because these are by far the heaviest of the group, the 500 RF deck and Pacemaker are the size of the Valiant but not nearly as heavy.

While you are in there it will probably be worthwhile to remove the reduction drive for cleaning and lubrication. The old lube is certain to have dried by now and pick up debris. This causes a stiff and "crunchy" feel and over time will result in permanent damage to the ball bearings and shaft, the bearings are standard items but unless you have a friendly machinist in the neighborhood a worn shaft is a problem.

Rodger WQ9E

Thanks Harry and Rodger. I came across the same type of material from a bin divider so will use that as a replacement. I also had the same VFO condition like pebbles were inside the drive just as Rodger described. So took the drive apart cleaned and lubed it and now works much better. Don't know how Johnson sold these transmitters as kits to novices. This is a very complex and compact rig, definitely not like a Heathkit build with many hand drawn pictures to guide the process.

Thanks again,
Al
K2DYH

Al,

You are welcome and I forgot to mention that you should check to see whether R-3, the 18K dropping resistor for the VFO VR tube, has been replaced. The original wattage rating is too low so it should be replaced with an 18K 5 watt (or 7-10 watt) unit.

The resistor can be replaced by removing only the left side of the VFO housing (your left looking from the front). The VFO will stabilize more quickly if the new resistor is mounted inside the VFO enclosure as was done originally. Some advise you to move it outside but in my experience the VFO will take far longer to stabilize.

If you Ranger has the keyer circuit note that even a very slight amount of heater to cathode leakage in the 12AU7 will hum modulate the VFO. So if you notice a rough sounding VFO note suspect this tube.

In addition to being a complex kit to build as you noted earlier there is a lot of heat generation crammed inside a small space so let the Ranger have plenty of ventilation room and don't stack anything on top. The higher power Valiant runs considerably cooler than the low power Ranger-mostly because of the much larger case.

Rodger WQ9E

You're welcome.

Let me add from my sample of one:

- R8 or R6 depending on schematic, but at any rate the V3 screen grid resistor had migrated to about three times its nominal value. This was, in large part, the cause of low drive on 80 meters.

- R9 (attached to the bandswitch under the chassis concealed by the bandswitch shield) This, in the end was the final cure for my low drive on 80 meters and a godawful chirp. This resistor was cracked, possibly from the R8 problem.

Harry, KT4AE