[Swan] 700CX HUM!!!

[Karl Heimbach]

David,

If you have another Swan power supply, try it.  If there is improvement, you
have the answer.

If not, take the cover off the supply and check the filter caps and diodes.
I suspect you'll find one or more perforated electrolytics that will need
replacement.  Also, check all the diodes as often you'll find one that has
given up the ghost.

I've recapped the power supplies on my 350, 500, 500CX and 700.  All had the
original caps and each had one or more electrolytics that were bad.

With any old piece of tube gear, you're better off bringing the voltage up
very slowly by using a variable transformer between the supply and the 120
VAC service outlet.

Hope this helps and good luck.

Happy 4th,

Karl - W5QJ



-----Original Message-----
From: swan-bounces at mailman.qth.net [mailto:swan-bounces at mailman.qth.net] On
Behalf Of David Shipley
Sent: Tuesday, July 04, 2006 12:56 PM
To: Swan at mailman.qth.net
Subject: [Swan] 700CX HUM!!!

I recently bought a 700CX SS-16B off ebay! When I connected it and turned it

on it had a loud hum from the speaker. I took the cover off the rig and 
turned it on again and I can see that the tube filaments do NOT light and 
that the bulb for the dial light BARELY glows! I guess there's something 
wrong in the power supply because the tubes and the bulb light if I connect 
12VDC to the right pin on the connection! Am I correct??? Can you give me a 
little help???
David Shipley....kf8ii 

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