[Johnson] Re: [Boatanchors] Johnson-Viking 122 VFO Freq. Jump

[Ed Swynar]

Hi Bill,

Good point you make there!

I've had similar experiences with the old 1929-style rigs I use for the
different AWA events here, & my Vibroplex...when I get "jumpiness" in the
signal, sure enough, the contacts on the bug are BLACK!

I guess there remains some residual sparking/arcing there, despite
precautions taken by yours truly...

Again, your point is very well taken, and well worth remembering...!

~73!~ Eddy VE3CUI - VE3XZ





----- Original Message -----
From: "Bill Stewart" <bstewart at ipass.net>
To: <johnson at mailman.qth.net>
Cc: <boatanchors at mailman.qth.net>
Sent: Thursday, February 24, 2005 2:08 PM
Subject: [Boatanchors] Johnson-Viking 122 VFO Freq. Jump


> For the past month or so I have been using the Viking 2/122 VFO quite a
bit on 40 & 80 mtr. CW. For a key, I primarily use a J-44 (also by EFJ).
Several weeks ago I noticed in my monitoring rx. that there was an
occasional freq. jump of anywhere from a few cycles to a hundred or so. It
only occurred on key closure....no jump while the carrier was on. I opened
up the VFO and sprayed the band switch, cked tubes, tightened hardware,
etc....it still had the jump. I did find the dropping res. at the vr tube to
be out of tol. and replaced it...still had the jump. One night while
listening to the jumping osc. in the rx., in a very small fit of frustration
I mashed the key down sort of hard and moved it from side to
side....noticing that the jump was occurring as I put pressure on the key
and moved it around. Long story short, I found that there was anywhere from
1.6 ohms to over 700 ohms ( that's right, 700 ) across the key plug. This
type of key uses a piece of flat spring steel for tension instead of the
coiled spring like the J-38. This flat spring steel also acts as a
connection between the top contact (part with the knob) and a terminal. The
tension screw makes the connection between the top contact and the spring
steel tensioner. I cleaned and polished the point of contact between the
tension screw and spring but still had some occasional jump so I jumped
around the the tension screw. So far, the problem has cleared up.
>
> I thought this was an oddity that you guys might be interested in...it
sure stumped me for a while...
> 73 de Bill K4JYS
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