From: "Gerry" 
Subject: Re: [drakelist] AC-4 power supply diodes


"Gerry"  made an utterence to the
drakelist gang
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The life of an electrolytic capacitor is directly related to applied =
voltage, ripple voltage, and temperature. It used to be that =
electrolytics were rated for at least 1,000 hours of operation at =
maximum specified voltage and temperature. The only way to find this out =
is to look up the data sheet or catalog information both of which are =
probably unavailable due to the passing of time. Since the Drake power =
supply has fuse protection, I say don't fix what isn't broke. Assuming =
of course that the proper fuse is in place. As long as the measured =
voltages concur with the specifications in the manual, don't lose sleep =
over it.
  ----- Original Message -----=20
  From: Eric Webner=20
  To: Drakelist=20
  Sent: Sunday, December 26, 2004 1:58 PM
  Subject: [drakelist] AC-4 power supply diodes


  I am working on my T-4XC (again!). I thought I would check out the =
power supply first, to make sure all voltages are good. They all =
measured (with DVM) good DC voltage, with very little AC (except for the =
filament supply, of course). Will such a measurement be accurate, or do =
I need a scope to check for AC?

  There have been some discussions about replacing the electrolytic =
filter caps and possibly the rectifier diodes. I see no leakage around =
any of the caps, and would hope to not have to hassle with it. The =
diodes would be much easier to replace, and I would like to know if it =
is practical to replace them while the unit is open, or should I "not =
fix what ain't broke?" If replacement is warranted, is there a suitable =
replacement or cross-reference for the B5G5 diodes? I'd like to use my =
1N400x rectifiers that I have in my junk box, if that is appropriate.

  Thanks for all your help!

  73,

  Eric
  KA8FAN



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The life of an electrolytic capacitor =
is directly=20
related to applied voltage, ripple voltage, and temperature. It used to =
be that=20
electrolytics were rated for at least 1,000 hours of operation at =
maximum=20
specified voltage and temperature. The only way to find this out is to =
look up=20
the data sheet or catalog information both of which are probably =
unavailable due=20
to the passing of time. Since the Drake power supply has fuse =
protection, I say=20
don't fix what isn't broke. Assuming of course that the proper fuse is =
in place.=20
As long as the measured voltages concur with the specifications in the =
manual,=20
don't lose sleep over it.

  ----- Original Message
----- 
  From:=20
  Eric =
Webner=20

  To: Drakelist">mailto:drakelist{at}zerobeat.net">Drakelist

  Sent:
Sunday, December 26, 2004 =

---