i have a johnson messanger viking II tube radio
i made a power coard and it trans mits but it dont trans mit all the time?
and one of the tubes lights up blue.....is this bad?
also is it ok to put a coolins fan on the top or will that mess things up?
tube radio
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juniorsamples
- Skipshooter
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tube radio
Last edited by juniorsamples on October 4th, 2008, 8:27 pm, edited 1 time in total.
73's junior
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juniorsamples
- Skipshooter
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juniorsamples
- Skipshooter
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drdx
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Hey, long time no see Junya, good to see you out there. I'm bumping too, but this small bit: Tubes of that type do need to be warm, and a fan isn't going to fix anything if it is broken. As old as it is, could be a tube or maybe a dried out capacitor? Just guessing. cya, -drdx
Yes it's me, Dollar-98, drdx, the original all maul, shot cawla on workin this no-fade technology.
-drdx
-drdx
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kg95
A lot of the people who really know tubes are dead or senile so they're no help because they forgot!
I think tubes that glow blue are no problem. I think there are others that will tell you there is a problem
with gassing but I don't think so.
I have one guitar amp that the 2 output tubes glow blue with output of 100 watts or more.
Lower output they just light up regular.
I think the blue tint means a lot of power in there, I'm not sure If you should see that all the time
in a cb or not. I know for the guitar amp there is a thing called bias which could cause the tubes
to draw too much (or too little) power when they shouldn't.
If they get very blue, I'm noticing a lot of distortion. It's fine for guitar, not as good for electric piano.
Don't know what to think about that with cb.
I think after blue comes white and then melting and possibly exploding so be careful if you start to see that.
If you have an intermittent problem, 2 good things to check is the pushbutton in the mic
and the relay contacts if there is one.
I think tubes that glow blue are no problem. I think there are others that will tell you there is a problem
with gassing but I don't think so.
I have one guitar amp that the 2 output tubes glow blue with output of 100 watts or more.
Lower output they just light up regular.
I think the blue tint means a lot of power in there, I'm not sure If you should see that all the time
in a cb or not. I know for the guitar amp there is a thing called bias which could cause the tubes
to draw too much (or too little) power when they shouldn't.
If they get very blue, I'm noticing a lot of distortion. It's fine for guitar, not as good for electric piano.
Don't know what to think about that with cb.
I think after blue comes white and then melting and possibly exploding so be careful if you start to see that.
If you have an intermittent problem, 2 good things to check is the pushbutton in the mic
and the relay contacts if there is one.
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Magnetron
- Mud-Duck Sr.
- Posts: 6
- Joined: October 2nd, 2008, 2:21 pm
Well, first you need to determine which circuit the blue glowing tube is in. Obtain a service manual for your radio.
A tube which glows such as you say usually indicates a bias voltage problem in that circuit, or a problem in the tube itself. First, try substitution with another tube of the same type. If that doesn't work then measure voltages at the tube socket and see if they are within specification per the service manual. Be careful when doing this - these voltages are quite high by today's standards and can injure you!
The Johnson messengers are fine radios and are easy to work on. But for any of this older stuff you really need to have the manuals.
As to your intermittent transmit, it is likely caused by dirty relay contacts as someone else suggested. Be careful not to damage the relay contacts when cleaning, as these relays can be hard to find. Use a small piece of Scotch Brite restaurant grille cleaning paper and rub lightly until clean, and then wipe with rubbing alcohol.
Another possible cause for the intermittent transmit is the mic PTT switch itself. Clean with rubbing alcohol or residue-free contact cleaner such as CRC brand QD® Electronic cleaner. Also check the microphone cord between the mic and the radio. They are often brittle and prone to breakage after so many years.
Hope this helps.....
Peace.
- Darrell
A tube which glows such as you say usually indicates a bias voltage problem in that circuit, or a problem in the tube itself. First, try substitution with another tube of the same type. If that doesn't work then measure voltages at the tube socket and see if they are within specification per the service manual. Be careful when doing this - these voltages are quite high by today's standards and can injure you!
The Johnson messengers are fine radios and are easy to work on. But for any of this older stuff you really need to have the manuals.
As to your intermittent transmit, it is likely caused by dirty relay contacts as someone else suggested. Be careful not to damage the relay contacts when cleaning, as these relays can be hard to find. Use a small piece of Scotch Brite restaurant grille cleaning paper and rub lightly until clean, and then wipe with rubbing alcohol.
Another possible cause for the intermittent transmit is the mic PTT switch itself. Clean with rubbing alcohol or residue-free contact cleaner such as CRC brand QD® Electronic cleaner. Also check the microphone cord between the mic and the radio. They are often brittle and prone to breakage after so many years.
Hope this helps.....
Peace.
- Darrell
