Ranger 1- VFO runs all the time

[K6ZA]

I am a glutton for Ranger 1's. Somebody stop me. I definitely need help. This is the 3rd.
That said, this newest one is the cleanest as I have seen. Traditional PTT mod was done by previous owner, beautiful looking audio, 6L6 modulators,  but the VFO is keyed all the time. Even in STANDBY mode (and tune position is full power out). The only way I can silence the vfo is going to crystal position. The relay looks out of closures, but the relay is not activated in cw anyway, so can someone point me to the best way to turn off the vfo for phone and cw.? The other 2 Johnson brothers seem to work fine in this regard.

Thanks,

Barry
K6ZA

[W3GMS]

Barry,
There were several version of the Ranger 1.  Does yours have the keyer tube?  If it does, that may be your problem.  Try adjusting the pot on the little shelf where the keyer tube sits.  If set incorrectly, it will key the VFO constantly. 

Good luck,
Joe, W3GMS 

[WQ9E]

I think Joe has found the solution to your problem but if you have the one with the keyer tube and the adjustment doesn't  work there are two other common faults with this circuit.  One is failure of the filter caps on the bias supply associated with the keyer tube so these may need replacement.  C89 in the keyer circuit is also prone to leakage if it is the original paper cap so it may need replacement.

Something else to watch for is it only takes a very small amount of heater to cathode leakage in the keyer tube to hum modulate the VFO so if hum shows up on the VFO signal  suspect it.  The crystal oscillator isn't as sensitive to this problem so just because the hum is only on the VFO doesn't necessarily mean it is the VFO itself and the keyer tube is much easier to substitute as a first test.

[K6ZA]

Thank you Joe and Roger !! Your responses are greatly appreciated.This Ranger does have the keyer/bias shelf. So when I get home I will try both your contributions. I replaced all the paper caps except the multi buried in the very corner. If that is c89 ?? I'll report out. Thanks again.

Barry
K6ZA

[W3GMS]

Hi Barry,

Let us all know how you make out.  Your solution is right around the corner! 

Regards,
Joe, W3GMS

[WQ9E]

If that is c89 ?? I'll report out. Thanks again.

Barry
K6ZA

Barry,
 
C89 is on the bottom of the added keyer chassis and is connected between socket X-36 and terminal strip X-37.

[K6ZA]

OK, The issue was finally indeed the pot on the bias shelf. But I know I tried that on first blush, and it did not cut off the vfo. Reviewing my actions, the last thing I did after testing that effort was to change out the C90A and C90B multi cap. Don't recall retesting subsequently.

Anyway, a couple of things. First, my schematic shows C89 as a .047mf to ground off R43. The parts page has it as a .05mf 200V, so I am confused. My schematic rev is 11/5/54. I set this ranger (#3) up on 80 tonight despite the solar flares. 50w into dummy load, 38+/- into the dipole. Also, the vfo function is a bit cranky. Drift is nominal after warm up but the frequency will pop around maybe 50 hz up or down an back without warning, then might be fine for a minute. Maybe the OA2 ?? Thoughts. Also, any reference pictorials showing the X36, X37 components, or things under the try ?

Can't tell you how great it is to get help here on the AMfone forum.

Barry
K6ZA

[WQ9E]

Barry,

For C89 use either a .047 or .05, it doesn't matter.   Both are "standard values" for that narrow capacitance range although today .05 is more commonly found than .047.  Given the typical tolerance range for capacitors the actual value of either could easily be equal to the marked value of the  other.

I don't have any photos of the underside of the keyer shelf and I don't believe any of the manuals (or the separate keyer modification sheets) have one either.

Have you changed R3 yet?  It is the 18K dropping resistor to the VR tube and the original is undersized (in terms of wattage).  Replace it with a modern 5 watt (or larger) resistor and I have found the VFO does stabilize more rapidly with the resistor mounted inside the VFO (some articles call for moving it outside of the VFO enclosure).  You can access this resistor through the left side of the VFO enclosure (your left looking from the front).  Replace the oscillator and VR tubes while you have the VFO open.  If this doesn't cure your jump it could be the wiper on the tuning capacitor but some have run into problems with some of the fixed capacitors in the VFO.  Hopefully your VFO instability is just the tubes.

[K6ZA]

Thanks Roger,

I'll replace the vr and oscil tubes next and see what happens. oK about the cap info. I did some shelf info in the construction pages. No pictorials, but good pieces related to the X-36,37 wiring. The vfo is remarkably stable other then the tiny jumps, which are no problem on AM, but I'm sure would not make for great CW contacts.
I was on the 3.870 West Coast Sat morning AM group with 7 other AMers, and got great audio reports on this little low power Ranger. So getting there. Again, many thanks.

Barry
K6ZA

[w5gw]

Frequency jump sounds definitly like a bad wiper connection in the VFO tuning cap or possibly in the trimmer caps in the VFO.  I had a Swan VFO that did the same thing as well as a VF-122.  Even tho the variable trimmer caps don't change values with operation, thermal expansion and bad conduction in the trimmer cap rotors were causing jumps.  Clean and reclean and reclean again with deOxit, just don't get carried away - a drop or two on a toothpick or a cotton swab is enough.  It will likely take more than one cleaning.  In the case of the Swan it took three cleanings before the corrossion broke down completely.  The plus side of all of this is you will then have an opportunity to do a VFO calibration.

[K6ZA]

Appears you are right about the trimmer caps. I cleaned them lightly and no more jumping. Just worked a local on 40 CW and the vfo was good as can be. So at lest the 40m trimmers are ok. Will bang on it on other bands. But, thanks for the comments. Greatly appreciated !!

Barry
K6ZA

[w5gw]

Appears you are right about the trimmer caps. I cleaned them lightly and no more jumping. Just worked a local on 40 CW and the vfo was good as can be. So at lest the 40m trimmers are ok. Will bang on it on other bands. But, thanks for the comments. Greatly appreciated !!

Barry
K6ZA

Barry,

You are welcome.  These old rigs are fun to work on, but sometimes a challenge.  The jump may come back, mine did in the Swan, but the VF-122 cleaned up nicely first time around.  Eventiually it can be made stable.

73

Gary