[TenTec] 238 Tuner Mod

Ron Castro ronc at sonic.net
Tue Mar 4 12:19:18 EST 2008


It has been a while since I did the mod, but as I recall, I had to unsolder 
the variable cap and coil to get closer to the solder tabs on the main 
switch.  I used long, thin needle-nose pliers to hook the tinned ends of the 
wires to the switch tabs.  It does take some manual dexterity to fit 
everything in.  It's a good idea to take some digital photos of the insides 
before you start unsoldering anything so you can remember where everything 
went.

         Ron  N6IE
      www.N6IE.com


----- Original Message ----- 
From: "Jack Mandelman" <modeler at bellsouth.net>
To: <tentec at contesting.com>
Sent: Tuesday, March 04, 2008 6:55 AM
Subject: Re: [TenTec] 238 Tuner Mod


>I made a similar mod to my 229B tuner.  However, instead of using
> doorknob caps I replaced the originals with 6KV 470pF Y5P ceramics.
> These capacitors are physically larger than the originals, having a
> thicker dielectric for increased breakdown voltage and larger plate
> surface area for increased current carrying capacity.  The drift problem
> was nearly completely, but not entirely, mitigated.  Complete
> disassembly of the tuner was unnecessary, since I was able to work in
> the tight space around the switch with small forceps.
>
> Now, I'm considering using the doorknob caps.  Would appreciate any
> suggestions about disassembly of the tuner for easier installation of
> the doorknob caps.
>
> 73,
>
> Jack K1VT
>
>
>> I few months back, I modified my TT 238 tuner by changing out the disc
>> ceramic
>> caps with surplus Soviet military doorknob caps, which dramatically
>> improves
>> the power handling capability on 160 and 80 meters.  Heating used to
>> cause the
>> SWR to 'drift', even at 100 Watts in some situations on 160.  The mod
>> worked
>> well, and if anyone is interested, I have all the details and pictures
>> on my
>> website at www.n6ie.com.
>>
>> 73,
>>         Ron N6IE
>>      www.N6IE.com
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
> 



More information about the TenTec mailing list