Have a look at the circuit board in your radio. You should see the number 481902C. Lots of these Maxon built AM radios were based around just a couple of PCBs.
Ticking an old box (Commtron box~)
- Otter
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Re: Ticking an old box (Commtron box~)
"To this day the words Stirling bridge conjour pride in every Scotsman's heart, while to an Englishman those same words conjour literally no feelings at all." - Cunk on Britain S1 E1
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Re: Ticking an old box (Commtron box~)
Fantastic Claude
thanks
Exactly the same and resistor present too - so I am right mine has broken off the signal meter black cable terminal
Great info there Cheers
thanks
Exactly the same and resistor present too - so I am right mine has broken off the signal meter black cable terminal
Great info there Cheers
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Re: Ticking an old box (Commtron box~)
See attached photo
with CB turned on I get 13,8v on the the middle leg of this transistor - nothing on the outer legs
is this normal?
with CB turned on I get 13,8v on the the middle leg of this transistor - nothing on the outer legs
is this normal?
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- Mitch
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Re: Ticking an old box (Commtron box~)
Yes, perfectly normal, one side is earth, middle is power and output, other is signal in.un-realistic wrote: ↑14 Feb 2022, 10:36 See attached photo
with CB turned on I get 13,8v on the the middle leg of this transistor - nothing on the outer legs
is this normal?
The perfect face for radio.
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Re: Ticking an old box (Commtron box~)
Great thanks
Just looking at trying to solve the low TX power - well I should say low TX power according to the units signal meter just over 1W
Hoping with the use of a SWR and watt meter I can confirm this output, am I to connect my dummy load to the SWR meter and then SWR to CB?
Thanks
Just looking at trying to solve the low TX power - well I should say low TX power according to the units signal meter just over 1W
Hoping with the use of a SWR and watt meter I can confirm this output, am I to connect my dummy load to the SWR meter and then SWR to CB?
Thanks
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Re: Ticking an old box (Commtron box~)
You don't need a swr meter if you have a dummy load.
Just put the dummy load in the ant socket on the power meter and radio to the other one.
Just put the dummy load in the ant socket on the power meter and radio to the other one.
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Re: Ticking an old box (Commtron box~)
But how then would I prove the true TX power output i.e. that the meters own signal indicator is correctly displaying power and doesn't need calibrated.
If in fact I am only producing 1+ W TX - where do I start diagnosing the cause?
If in fact I am only producing 1+ W TX - where do I start diagnosing the cause?
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Re: Ticking an old box (Commtron box~)
You need an accurate power meter.
Don't believe the built in signal meter.
Don't believe the built in signal meter.
- Buick Mackane
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Re: Ticking an old box (Commtron box~)
Dummy load & a decent quality power meter, The radio might just need the TX Stages aligned, But keep in mind that not every 27/81 radio is capable of producing the full 4 watt legal limit.
I Am the great cornholio are you threatening me ?
- Otter
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Re: Ticking an old box (Commtron box~)
I'd look at the output transistor and see whether it's the correct one for the radio. If it looks like it may have been replaced, try to work out whether the transistor is a genuine one.
"To this day the words Stirling bridge conjour pride in every Scotsman's heart, while to an Englishman those same words conjour literally no feelings at all." - Cunk on Britain S1 E1