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Johnson Ranger 1 - CW Tone During Phone Mode Transmission




 
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Author Topic: Johnson Ranger 1 - CW Tone During Phone Mode Transmission  (Read 455 times)
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W1TTL
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« on: June 30, 2020, 08:13:07 PM »

Hi everyone,

New to the forum here.  I've been wanting to get a Johnson Ranger 1 for some time now and I finally found one.  

I went through it and did all the regular things: replaced all the electrolytics, all the wax capacitors, as well as R3 in the VFO with a higher wattage resistor.  I also cleaned and lubed the planetary drive and cleaned all switch contacts and potentiometers.  After following the tune-up procedure in the manual, I had about 20W output.  After replacing the 6146 driver tube, I can get out about 45W on CW.  FB.

My Ranger has the add-on keying circuit (http://bama.edebris.com/download/johnson/ranger/keyer_modification/keyer_modification.pdf) and instead of the voltage dividing circuit, a transformer mounted on the keyer plate is used for the 6AL5 voltage supply.  It also has the PTT relay modification.  Other than that, it looks pretty stock and is a factory built unit, judging by the riveted tube sockets.

Operating in CW sounds and appears fine except for a slight hum.  The strange thing is when I switch to Phone and key the mic, i hear only the CW tone in my receiver!  It happens whether I am using the VFO or a crystal.  I thought, hmm... maybe the key line is getting grounded when it should be going to the multiplier cathode?  When in phone, I can close the key and hear the CW tone transmitted, too... I'm not sure if that is normal.  Looking at the schematic, I see that when the operate switch (SW4A) is in phone, the key line and multiplier cathode are supposed to be connected together and grounded.  So, it's supposed to be doing that.

Any thoughts as to where I could check to see why the CW tone is getting keyed in phone?  I put the operate switch in phone and bypassed the relay for the "SW4A Tab 8" relay side and that connection is definitely causing the CW tone to happen.

Thanks and 73,
Tony W1TTL

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WA1MNQ
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« Reply #1 on: July 01, 2020, 11:38:14 AM »

Hello Tony,
                     Try pulling the modulator driver tube, its a 12AU7. That transmitter has feedback
between the two modulators and that driver tube. If the phase is wrong on the plates of the modulator tubes to the feedback winding and driver tube you could get oscillations.
Pulling the driver tube will open up that path and if it stops then you can try reversing the two plate connections at the tubes.

Mike
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WA1MNQ
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« Reply #2 on: July 01, 2020, 09:07:18 PM »

Tony,
             There is NO CW tone in that transmitter. If you want that listen to the on air signal when on CW from the RX.

Mike
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W1TTL
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« Reply #3 on: July 01, 2020, 09:38:21 PM »

Mike,

Thank you for your replies.

Sorry, I forgot to mention that I am listening to the Ranger on a solid state Hallicrafters receiver tuned to the same frequency.

I did pull the 12AU7 audio driver (V8) and I still hear the CW note in the receiver when I engage the PTT relay while in phone.  I disconnected the mic to take that out of the system, however, I still hear the CW tone transmitted (on the receiver) when I manually engage the PTT relay. 

Any other thoughts?

Thanks for the help!

Tony W1TTL
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WA1MNQ
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« Reply #4 on: July 01, 2020, 09:51:18 PM »

Hello Tony,
                   Well if the BFO is switched OFF on that receiver, there should be no tone. Maybe a tiny hum from the caps in the transmitter, but no tone. I did assume that you would have checked that BFO off option.
Be certain that there is no modulator current, except the idle current and if so then you can't get audio on that carrier so it could be a receiver overload issue.
Not there, can't help in that way.

Mike
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Pete, WA2CWA
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« Reply #5 on: July 01, 2020, 10:59:39 PM »

Did you try pulling the keyer tube (12AU7)?
C89 0.47 Mfd, if it's leaking, it will cause the VFO to remain on. C89 is part of the keyer circuitry.
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Pete, WA2CWA - "A Cluttered Desk is a Sign of Genius"
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« Reply #6 on: July 02, 2020, 10:03:58 AM »

Tony,

So you’re saying when you key the PTT in AM mode you’re hearing the carrier in your receiver, but no modulation, correct?  First, check your mic plug for bad or broken leads, mic element/leads, then speech amp and modulation sections. Check for bad tube or open transformer in the speech circuits. Then start checking the ancillary components in those stages. Does your mic work with other radios?

Brad
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W1TTL
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« Reply #7 on: July 02, 2020, 07:04:20 PM »

Gentlemen,

Thank you for the replies!  I am used to fixing hybrid transceivers, so this is new territory for me.

Mike: I think you hit the nail on the head.  I didn't realize it but my Hallicrafters S-120A had the BFO turned on!  Of course, once I turned off the BFO on the receiver the tone went away when keying up in phone.  Thank you for suggesting that!

I am not getting any modulation (the meter in "mod" doesn't move from a resting current of 51mA even when I turn up the audio knob).  I guess I need to start from the first audio amplifier section and move my way up.  After I confirm the mic is working, of course (thanks, Brad)! (It was the last time I used it on my Kenwood TS-520S, but you know how that goes...)

Pete: I had replaced C89 because I had a chirp in my CW signal.  (It is .05uF for me since I have the added keyer circuit.)

Thanks all,
Tony W1TTL

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