[R-390] VU Meter Issue...newbie on first 390a

[Jacques Fortin]

Hi Dave,

If you can disconnect the two wires going to the meter, measure the meter resistance.
It should be around 7500 ohms.
If it measures open, this is bad.... Maybe the internal rectifier have failed, or worse...
A good R-390A VU meter should indicate 0VU when connected to an audio signal generator delivering 1Volt Peak at 1kHz.

73, VE2JFE


-----Message d'origine-----
De : R-390 [mailto:r-390-bounces at mailman.qth.net] De la part de R. David Eagle via R-390
Envoyé : 6 avril 2016 22:23
À : 390 List <r-390 at mailman.qth.net>
Objet : [R-390] VU Meter Issue...newbie on first 390a

Hello all...Today was my first day of powering up my very first motorola 390a that I have been slowly working on over the last year.  I went through and checked all tubes with my tv7 and found a couple that needed to be replaced.  Today was the day that the speaker finally got hooked up and the rig warmed up.  Much to my surprise, I was copying cw on 40 after a few gleaming moments.
One thing I noticed though, was my VU meter was not working what so ever and I have searched around for common fixes/problems but haven't turned anything up.  Is there any common problems to look for outside of replacing the meter?
Also...I noticed that the carrier meter has a film on the inside of it that is almost brown.  I am somewhat reluctant to pull it apart due to the whole radioactive particle scare, but are these easy to disassemble and clean?


Thanks in advance,
DaveKB8NNU
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:R-390 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html