With my 238 tuner I too experienced issues with observed SWR drifting at
higher power values, but only under certain antenna configurations.
Conclusion, the 220pf capacitors wired parallel and associated with the Hi Z
and Lo Z switch were getting hot, thus changing values. I replaced each
pair with a Russian made 470 pf 2KV doorknob style capacitor. These can
be found on E-Bay for a nominal price.
Mounting was accomplished by drilling holes through the bottom plate in the
area of the original capacitors. It is a tight place to work but with a
little planning the result is a very nice professional job.
Problem solved.
73
Bob, K4TAX
----- Original Message -----
From: "David Cuttler" <davidcuttler@yahoo.com>
To: <tentec@contesting.com>
Sent: Monday, July 02, 2012 11:30 PM
Subject: Re: [TenTec] 229 swr circuit
I own a 229 tuner, and I have never used the meter. If it ever died, I
wouldn't care because it is of limited use. I would recommend finding a
good external meter that will read CW & PEP like the Ameritron AWM-30 which
is what I use, and forget about the 229 meter.
Of more importance are the crummy disc capacitors in the tuning circuit.
My tuner would not hold a setting, and the swr would drift all over when
used on the lower bands until I replaced all of the the disc caps with
Russian door knob caps that I purchased off Ebay. Now my 229 tuner is rock
steady, and I have not had any issues with it after the modification.
If your antenna does not need a tuner, then you will be happy with the 229
as it is built, but if you are using antennas that are far from 50 ohms
like my doublet that is fed with 450 ohm window line, the 229 in the
factory configuration is a lousy piece of equipment.
The meter is more bother than it is worth, unless you are like me, and
need to have everything working correctly just because it's there!
Sorry for the rant.
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