[ARC5] BC-455 not working

[Kenneth G. Gordon]

On 13 Jan 2018 at 16:43, kg4kgl at gmail.com wrote:

> I need help. This modified receiver was converted to 12v filament
> operation.

That shouldn't matter....IFF it has been done correctly. Connect filament voltage to it then 
feel the tubes after, say, 5 minutes. If one is cold, then it is either not getting filament 
voltage, or the tube is dead. If you find a cold tube, I'll bet the filament string wasn't re-wired 
correctly. Find the bad connection and fix it.

> The BFO can had a screw missing, so I assume someone was in
> there. I removed it it, but it looks stock. 

If the BFO wasn't working, that would have ZERO effect on signals through the receiver. 
Ignore that for now.

> I am getting pretty much nothing on the headphones. I can adjust the
> trimmers on the IF cans and get a higher background noise. 

ACK!! The "Golden Screwdriver". I have yet to find ANY of my hacked up receivers with 
totally out of adjustment IF cans. Now you will have to realign them.

> Where should I be looking next?

First, find the cold tube and fix it.

Then, as someone else here mentioned, download the manual, and go through the entire 
alignment procedure.

For the BC-455 you will need a signal generator which will output 2830 kHz for the IF 
alignment, and anything between 6 and 9 MHz (to begin with) for the RF alignment.

Feed a WEAK 2830 kHz signal into the connection on the top of the 12K8, then connect a 
DMM, or (better yet) an analog VOM, to the audio output set for AC volts, and align the IF 
trimmers for maximum AF output. You will have to keep reducing the level from the 2830 
kHz signal generator so as to not overload the audio stages.

Ken W7EKB

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