President George ASC deaf
- 13EL121
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President George ASC deaf
Hi friends, got a President George ASC which was screwdrivered. Fixed all issues with help of service manual. But the radio is still stone deaf.
Replaced Q8 which is a 2SC1674 but didn't help.
You can hear strong signals round about S9 but S-Meter shows nothing. At very strong signals the meter is working.
So I think there is a problem in the RX amp stage.
Any help is welcome. Thank you.
73s Ralf
Replaced Q8 which is a 2SC1674 but didn't help.
You can hear strong signals round about S9 but S-Meter shows nothing. At very strong signals the meter is working.
So I think there is a problem in the RX amp stage.
Any help is welcome. Thank you.
73s Ralf
- ch25
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Re: President George ASC deaf
Is it the same on AM and FM?
Than disable AGC and check.
Chris
Than disable AGC and check.
Chris
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
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- 13EL121
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Re: President George ASC deaf
Hi Chris, yes all modes the same.
- ch25
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Re: President George ASC deaf
SSB the same?
When you touch FL3 legs with a finger can you hear BC radio stations?
Do you have RF probe? You could put strong signal and with RF probe trace where signal disappear starting from antenna.
Is it transmitting OK?
Isn't it just tuned wrong? Did you try to readjust L2, L6, L8?
Is C201 ok?
Remove D3 and D4 and test if sensitivity improved.
Also I would check for continuity L2, L6, L8 and FL401. Happens to me a few times, that when radio had a problems, someone tried to fix cold solder joints. When too much heat applied winding inside tuning cans is de-soldering from filter leg inside.
Chris
When you touch FL3 legs with a finger can you hear BC radio stations?
Do you have RF probe? You could put strong signal and with RF probe trace where signal disappear starting from antenna.
Is it transmitting OK?
Isn't it just tuned wrong? Did you try to readjust L2, L6, L8?
Is C201 ok?
Remove D3 and D4 and test if sensitivity improved.
Also I would check for continuity L2, L6, L8 and FL401. Happens to me a few times, that when radio had a problems, someone tried to fix cold solder joints. When too much heat applied winding inside tuning cans is de-soldering from filter leg inside.
Chris
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...
- 13EL121
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Re: President George ASC deaf
Hi Chris.
No RF Probe here. TX is fine. All cans are tuned to maximum. Will check filter and C201 and D3 and D4 again. Thanks mate!
No RF Probe here. TX is fine. All cans are tuned to maximum. Will check filter and C201 and D3 and D4 again. Thanks mate!
- ch25
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Re: President George ASC deaf
Build rf-probe
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
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- cb4ever104
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- Location: España
Re: President George ASC deaf
That was one of our first projects in college in 1983 . We built them inside plastic syringes I've still got mine , and it still works
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
- 13EL121
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Re: President George ASC deaf
Yes would be better to build one.
- cb4ever104
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Re: President George ASC deaf
Best to use them with an analogue voltmeter , instead of digital .
Sammy
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
- 13EL121
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Re: President George ASC deaf
Fixed!!! Radio is back again. Thanks Chris for the input. C201 was dead. Was recognized as a 16meg ohm resistor. I put in a standard 56pf ceramic cap which works without any problems.
Thanks for your help!!
Thanks for your help!!
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- ch25
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Re: President George ASC deaf
Glad I could help.
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...