[Boatanchors] Two questions

[manualman at juno.com]

HRO-500: For starters, you might try rocking the bandswitch back and
forth between the various positions. Not an uncommon problem if the
receiver is left in one bandswitch position for a long time.
You also should review the boatanchor archives. Lots of HRO-500
discussions over the years. Go to  http://www.w9wze.net/ At the bottom 
under HOT LINKS, Click, Search the QTH.net Lists.

Pete, wa2cwa

On Wed, 22 Apr 2015 22:56:50 -0400 Howard Ritter <hlritter at bex.net>
writes:
> I have two problem BAs that I’m trying to rehabilitate for eventual 
> sale as I’m downsizing my life and home. Any suggestions?
> 
> 1. A National HRO-500. This was working properly the last time I 
> used it several years ago. Firing it up now, I get no audio and the 
> Phase Lock light stays on at most frequencies.  Where to start?
> 
> 2. A TMC GPR-90. This was also working properly when last used 
> several years ago. Now I get a very loud 60 Hz hum in the phones as 
> soon as power is applied. The volume does not vary with adjusting 
> the volume knob and is so loud that I can’t tell whether there’s 
> any audio underneath. Is this a recognized failure mode for 
> hollow-state receivers? Something shorted in the audio output 
> circuit? Tube? Capacitor?
> 
> Thanks for your suggestions. I’ll report back.
> 
> —howard n7exn