QRX-9001 startup suggestions

[Scotteboy]

Hi all, after a long pause in activity, I have recently recapped a QRX-9001. I have recapped and/or repaired quite a few receivers with your kind help over the years and am at a point I would like some input or direction to a thread on this particular receiver. I have fully recapped it and did all the work for a good restoration including all the side to side work on the dual sided board to restore this beast. I have attempted to bring it up on DBT and get power and lights but then I hear a low growl. No fuses blown ,light gets bright and dims but then brightens a bit and the growl comes in. I unplugged the amp boards and it is still there. I believe the power relay is trying to engage but is struggling for voltage/current as the source of the growl but I would like to know if there is a better way to bring this up, I am jumpy after all this work and want to be very conservative. I have double checked all work and verified output transistors for gain and leakage along with proper placement so all that should be good. I may just be going too conservative and need to plug it in directly but thought It would be best to ask first. I also already talked to QRX restore and they were most helpful in verifying the output transistors placement as the SM was incorrect on the layout.

 

[CrSens]

What size bulb are you using? 60W is probably not enough.

 

[Skywatcher]

Hi all, after a long pause in activity, I have recently recapped a QRX-9001. I have recapped and/or repaired quite a few receivers with your kind help over the years and am at a point I would like some input or direction to a thread on this particular receiver. I have fully recapped it and did all the work for a good restoration including all the side to side work on the dual sided board to restore this beast. I have attempted to bring it up on DBT and get power and lights but then I hear a low growl. No fuses blown ,light gets bright and dims but then brightens a bit and the growl comes in. I unplugged the amp boards and it is still there. I believe the power relay is trying to engage but is struggling for voltage/current as the source of the growl but I would like to know if there is a better way to bring this up, I am jumpy after all this work and want to be very conservative. I have double checked all work and verified output transistors for gain and leakage along with proper placement so all that should be good. I may just be going too conservative and need to plug it in directly but thought It would be best to ask first. I also already talked to QRX restore and they were most helpful in verifying the output transistors placement as the SM was incorrect on the layout.

With the driver boards out, use a 100w Incandescent bulb. If it still gets bright, you have a problem somewhere and need to recheck your work.

 

[Scotteboy]

Thank you all , I had some trouble finding a bulb , I was using a 72 watt halogen and found a 150 watt incandescent rough service bulb and will try this weekend !

 

[Scotteboy]

So put 150 watt incandescent in dbt. light goes bright then fades to almost nothing but now stays dim. So far so good but Power relay chatters whole time with or without amp boards installed . Going to check driver transistor to relay and power to relay next.