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Date: Wed, 29 Aug 2001 16:04:58 -0400
From: Cameron Bailey <kt3a at juno.com>
Subject: [Elecraft] Fw: KT3A: RE: Dead Band K1 syndrome

- --------- Forwarded message ----------
From: "Gary Surrency" <gary at elecraft.com>
To: "Cameron Bailey" <kt3a at juno.com>
Cc: "CSinfo" <csinfo at elecraft.com>
Date: Wed, 29 Aug 2001 10:13:43 -0700
Subject: KT3A: RE: Dead Band K1 syndrome
Message-ID: <LPBBLHIBMDDJEAFAKDDOAEKMFMAA.gary at elecraft.com>

Could be a weak 22MHz Premix crystal. Listen for its signal on another
rig,
or use a scope or good quality RF probe at pin 6 of J6 or P1. This is the
Premixer output, and it should be stable and at least 200-300mVpp.  If
you
suspect this is the problem, we'll be happy to send you a new 22MHz
crystal.

Also see if the Premixer band-pass filters are well-peaked. Peak all of
the
Toko inductor slugs for each band, watching for maximum level in TX with
about 1-2w of RF output.

It would also be an excellent idea to inspect all of the connections
associated with the 20m band, the connectors, caps, etc. Resolder any of
them that look suspect or possible a cold solder joint.

Also check for excessive solder on the 22MHz Premix crystal, since it can
wick up under the crystal can and cause an intermittent short. Heat its
pins
and lift the crystal off of the PCB slightly if this seems likely.

- --
73, Gary AB7MY
=========
gary at elecraft.com
Elecraft Technical Support
========================================

- -----Original Message-----
From: Cameron Bailey [mailto:kt3a at juno.com]
Sent: Tuesday, August 28, 2001 7:19 PM
To: elecraft at qth.net
Cc: support at elecraft.com
Subject: Dead Band K1 syndrome


I went to fire up #595 K1 and found that band 2 was dead.
This is a 40/20m set with 20m being band 2.

I noticed that the signals leak through upon initial turn on until all
the relays complete their clicking and settle to their correct settings.
This is about a half a second.

I checked all three latching relays on the filter board and they have
continuity to the board pin outs.
So, I am assuming that they are okay.  They switch back to band 1 too.

I would love to spend more time troubleshooting, but I have a basement to
finish off and I like to take breaks and work 20m when I get the time.

So, if you have some ideas, let me know.

Cameron, KT3A

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