Hi Allan,
I suggest you use the best RCA phono cables you can find, or build you
own using RG-58, so that you know what kind of shield they have. I had
some trouble with my 253, which seemed to be RF getting into the keying
loop. The loop passes through a relay in the 253. Unfortunately the
relay is mounted on the same board as the SWR bridge in the 253, and
very close to the bridge. Even with the best cables, there is likely to
be some coupling of TX RF into the keying loop, because of the proximity
on that board. I thought about adding a shield of some sort between the
keying loop and the SWR bridge. Still have not tried it and still have
not fixed that problem in my 253.
Check out :
http://lists.contesting.com/archives//html/TenTec/2003-09/msg00429.html
DE N6KB
Allan Taylor wrote:
A question for 253 tuner users. I recently acquired two (2) 253 tuners
to assist in automating my station. The
instructions say to use interconnecting cables of RG174 for the QSK
loop. These cables will need to have RCA phono
plugs on them. Is there an obvious source of high quality (read that
well-shielded) cables with phono plugs? Will R/S
cables do? Would it be necessary to use UHF to RCA phono adapters and
RG58 equivalent? One of the tuners came with
two such adapters...
The setup is with an OmniVI and Hercules II amp. I will be doing the
same on occasion but with a Titan instead of the
Herc II.
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