From: "Jim Shorney" 
Subject: [Drakelist] TR7 50 Kc spurs


-----BEGIN PGP SIGNED MESSAGE-----



A while back I posted a query about the cause of some nasty 50 Kc spurs
in my TR7 that allowed me to work stations on three discrete
frequencies at the same time if strong enough.

It looks like the major culprit is a bad 220 uF/16v capacitor on the
power supply board.  All outputs have measurable 23 Kc ripple.  On the
cap itself, it's around 5v P-P.  There's enough noise coming out of
that board that an open scope probe across the bottom of the chassis
picks it up quite well.  Keeping this radio off the air was a good
decision...  I'll be securing a replacement this week.

Also noted: the +10v output was running at 11.something.  Root cause:
dirty adjustment pot.  It looks like a full alignment is in order.

- --
Jim Shorney      -->.<--Put complaints in this box
jshorney{at}inebraska.com
nu0c{at}amsat.org
Ham Radio NU0C
Lincoln, NE, USA
EN10PT
http://incolor.inetnebr.com/jshorney/
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQCVAwUBPp4y00CBN4ScxcExAQGrCwQAmvZRTy8iFNo6/ADXaJcsWcg4uTawcYNb
vk9wVEwU8WYfaNf9r4eKrGcBIdjdYZa5YtVClj+VqUbgBOWgxHOJ+Ex9wwNSMiv5
zeudkT5czSGgrWz7E6PyVsIVI2oWDDNPBR/VKDkeRS995Prf2t99pV9JLls8Ts9W
41SqX90Opfg=
=3B2V
-----END PGP SIGNATURE-----


----------------------------------------------------------------------
Submissions:        drakelist{at}zerobeat.net
Subscribe:          majordomo{at}zerobeat.net - subscribe drakelist in body
Unsubscribe:        majordomo{at}zerobeat.net - unsubscribe drakelist in body
Hopelessly Lost:    majordomo{at}zerobeat.net - help in body of message
Brought to you courtesy of TLCHost.net  http://www.tlchost.net
----------------------------------------------------------------------

---