[AMRadio] Legal-Limit tuner advice....?


John Lawson jpl15 at panix.com
Fri Aug 18 00:52:16 EDT 2006



On Fri, 18 Aug 2006, W7QHO at aol.com wrote:

>
> In a message dated 1/12/06 8:31:16 AM, jpl15 at panix.com writes:
>
>> On Wed, 11 Jan 2006, W7QHO at aol.com wrote:
>>
>>>>
>>> Quick and dirty, just try grounding one side of your ladder-line at the
>> input
>>> end and feeding the other side off the single ended output of your ATU and
>>> see what happens.   SWR figures might be better (but could also be worse).
>>
> John,
>
> Did you ever try this?   If so, what were the results?


   Yes, I did - results not good at all, antenna would not tune and the 
Transmitter complained at me bitterly...  ;}   I also built in a DPDT 
knife switch in the feedline after the tuner - it's mainly for grounding 
during t-storms, but I played around with various (semi-calculated) values 
of capacitors and coils...  on 10 meters the use of various paralelled 
caps made improvements, but tuning became very critical, and there's 
nothing much that interests me up there - I *do* like to work 20M RTTY , 
and have yet to try PSK32 into the Valiant.

   I'm still gathering facts, and the Listmembers have been quite helpful - 
everyone likes the Palstars, but the big Ten-Tec also has impressive 
specs....  I intend on converting a broadcast transmitter for use in the 
shack, so the Tuner needs to be able to withstand 100% duty-cycle at 
Legal Limit.  Ultimately I'll tune the feedpoint of the antenna itself, 
and just run 50-ohm line from the transmitter out to the "doghouse" if you 
will.


   Cheers

John  KB6SCO

Who just shut the rigs off after a nice AM QSO on 80....



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