[AMPS] SB220 problems

Sat, 26 Dec 1998 19:50:02 +0800

Hi All,
          A friend of mine in Virginia is having the following nightmare
with his SB220. Can anybody help?

I have copied and pasted his e-mail and deleted all the expletives. I
think. If there's still one in there, please forgive me and him. It's
Christmas.

[207.172.209.183])
	by smtp4.erols.com (8.8.8/smtp-v1) with SMTP id GAA24996;
	Sat, 26 Dec 1998 06:29:05 -0500 (EST)
Message-ID: <3684C91C.6B92@erols.com>
Date: Sat, 26 Dec 1998 06:31:40 -0500
From: Bellford Kellem <belkel@erols.com>
Reply-To: belkel@erols.com
X-Mailer: Mozilla 3.01C-KC032698  (Win95; I)
MIME-Version: 1.0
To: vk6apk@eon.net.au
CC: w4ubc@visi.net
Subject: Help
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Alek,
For 40 ------------ years of my ------- life I was a practicing electronic
engineer. I have designed and built every kind of power supply you can
imagine  from little 5 volt units to 30kv radar power supplies. Half
wave, full wave , bridge, 3 phase, etc. I have installed 1000s of filter
capacitors with never a ------- problem.

My SB220 contains a small transformer with two windings. One winding
supplies the filament voltage for the 3-500zs and the other supplies
bias and relay voltage at 120volts. One side of the relay coil is
connected to this little half wave supply. The other side of the relay
coil goes a jack on the back of the linear. When this jack is grounded
it closes the relay and the linear goes into the transmit. From the
banded end of the diode rectifier, a 20ufd, 160 volt electrolytic
capacitor is connected from this point to ground. Without this
capacitor  the relay will not close. It just chatters from the pulsating
dc voltage. Just what you'd expect.

I have gone through at least 10 capacitors, and each one explodes after
a short time. Six of them were supposedly new stock. Last week I took
one of these "new caspacitors" and preconditioned it by putting it
across a dc supply which I increased from 20volts to 125 volts 20 volts
at a step, leaving it for 2hours at each step. I installed this
capacitor yesterday morning and spent most of the day dxing on twenty
meters. I gave that ------- linear a workout like it ain't had in 25
years. Got reports from all over the world from S9 to "loudest signal on
the band". I thought I had it made when at 3:45 local time that
capacitor let go like a shot gun blast. Blew pieces all over the -------
living room.

I am at my wits end. You mentioned you were "dropping a couple in the
mail" If you have done so, bless you. If you have not get your ------- ---
--- to the sodding post office and do so. I'll pay, whatever it
cost. I'm ------!
73, de KC4DWI

Any Ideas?

73 de Alek, VK6APK.

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm