Author Topic: Realistic TRC-457 restore  (Read 4123 times)

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Offline The Radio Shop

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Realistic TRC-457 restore
« on: December 14, 2014, 04:46:48 PM »
Here I have a un hacked unmolested TRC-457. This radio is as original as I have seen.  I did replace the filter cap on the power supply board to get it to turn on. There is not TX or RX but I have not fully tested the radio yet.  All I have done was cleaned the front panel due to heavy nicotine deposits.

I checked the 10.240 on IC7 pin 9 and 10 and it is present. I also checked for frequency on TP-6 and it is there. This leads me to think the PLL is ok but will need further testing.
Buddy kc4umo

Offline The Radio Shop

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Re: Realistic TRC-457 restore
« Reply #1 on: December 14, 2014, 04:47:32 PM »
Couple more pics
Buddy kc4umo

Offline sonoma

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Re: Realistic TRC-457 restore
« Reply #2 on: December 14, 2014, 07:57:21 PM »
you may have some 10 volt caps going down on you. right by the relay is a diode and cap 10 volt I believe. they can go bad and kill rx and tx. at least they did on 2 of my old washingtons I refurbed a couple years ago. believe the diode was a zenor  if memory serves me right. I think they both are in the same circuit together.

Offline The Radio Shop

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Re: Realistic TRC-457 restore
« Reply #3 on: December 14, 2014, 08:01:58 PM »
you may have some 10 volt caps going down on you. right by the relay is a diode and cap 10 volt I believe. they can go bad and kill rx and tx. at least they did on 2 of my old washingtons I refurbed a couple years ago. believe the diode was a zenor  if memory serves me right. I think they both are in the same circuit together.

That's a very good diagnosis Sonoma. Those caps can cause lots of issues. Plan is to replace all electrolytic  caps and tantalums.
Next step is to check all psu voltages and ripple.
Buddy kc4umo