• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Wawasee style JB12 " no bias components"

That is the one I tried Nomadradio and all it wanted to do was chatter, didn't work well unless I cranked up the deadkey View attachment 70684
If I had to make that relay work, I might try spinning some more magnet wire on the solenoid to bring up its DC resistance or, stretching the spring a tiny bit to reduce its mechanical resistance. In one case, I've even swapped the solenoid from the original relay to the replacement, in order to keep it compatible with the circuit. I wouldn't expect changing the polarity to make any difference here.
 
If I had to make that relay work, I might try spinning some more magnet wire on the solenoid to bring up its DC resistance or, stretching the spring a tiny bit to reduce its mechanical resistance. In one case, I've even swapped the solenoid from the original relay to the replacement, in order to keep it compatible with the circuit. I wouldn't expect changing the polarity to make any difference here.
Yeah, I actually think it is the stronger spring causing it I believe, maybe I will mess with it later if need be
 
This is why we won't repair a tube-type keying circuit. Feeding the 6.3-Volt AC heater voltage into two diodes and two filter caps gets you just over 12 Volts DC to power a 12-Volt relay and transistor keying circuit. I can make those sensitive down to a couple of tenths of a Watt without chatter.

Tube-type keying circuits are tricky to make sensitive and stable. Changing the return-spring tension runs the risk that it won't unkey reliably. The 6AQ5 never really shuts off the relay coil's current. Just drops it low enough to unkey. A weaker spring may cause it to stay keyed. Nothing ventured, nothing gained.

When they work okay, nothing is broke that needs fixing, but when they break I just go with a low-voltage relay and a keying circuit I can trust.

If you have spare 6AQ5 tubes you may find that a different tube behaves better.

Only one way to find out.

73
 
This is why we won't repair a tube-type keying circuit. Feeding the 6.3-Volt AC heater voltage into two diodes and two filter caps gets you just over 12 Volts DC to power a 12-Volt relay and transistor keying circuit. I can make those sensitive down to a couple of tenths of a Watt without chatter.

Tube-type keying circuits are tricky to make sensitive and stable. Changing the return-spring tension runs the risk that it won't unkey reliably. The 6AQ5 never really shuts off the relay coil's current. Just drops it low enough to unkey. A weaker spring may cause it to stay keyed. Nothing ventured, nothing gained.

When they work okay, nothing is broke that needs fixing, but when they break I just go with a low-voltage relay and a keying circuit I can trust.

If you have spare 6AQ5 tubes you may find that a different tube behaves better.

Only one way to find out.

73
Thank you Nomad, you explained that very well ! Actually the original relay was acting up after I cleaned it and it didn't want to unkey, I ended up putting just a little bit more tension on the spring and now it works fine, however this is the original 2 prong or contact I am talking about
 
This is why we won't repair a tube-type keying circuit. Feeding the 6.3-Volt AC heater voltage into two diodes and two filter caps gets you just over 12 Volts DC to power a 12-Volt relay and transistor keying circuit.

73
How do you do that when the standard transformer has its 6 volt filament winding internally wired in series with its 37 volt bias winding? I don't see how there is the isolation available to use a voltage doubler, when that winding is already referenced to a positive ground power supply. Maybe they've used different transformers over the years however, I couldn't get any of mine to isolate the filament winding from the bias winding.
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Mark Malcomb:
    Hello BJ. Been a long time since I've been on. You doing well? Mark Malcomb
  • @ Naysayer:
    I’m
  • @ kingmudduck:
    Hello to all I have a cobra 138xlr, Looking for the number display for it. try a 4233 and it did not work