Re: St. Louis Tuner Kit


From: NONE (
Date: Sun Dec 31 1995 - 21:36:33 EST

On Sat, 30 Dec 1995 16:58:45 EST (chuck adams)
>NorCal is now taking orders for the St. Louis Tuner which will
>be delivered in the Spring of 1996

On Sat, 30 Dec 1995 23:54:14 EST wrote:
> the article clearly
>shows, the other designs (with the exception of the inductive Tee, which is
>challenging to construct and tune) are lower efficiency designs.

>...harmonics and parasitics above the operating frequency are not suppressed.
>...parasitics and harmonics that are "received" by VCRs, televisions, and
>stereos. The Pi-Net, however, acts as a true bandpass filter, and
>attenuates spurs above and below the operating frequency.
> High quality #16 or larger wire should be used for
>wiring and the inductor.
> ...the Pi design is much more
>efficient over a wide variety of loads.
>Frankly, it scares the hell out of me when new tuner designs are introduced
>as the panacea for matching balanced and unbalanced loads under a wide range

On Sun, 31 Dec 1995 06:48:40 EST wrote:
>I can only reaffirm your remarks ...
> In any ATU
>network, a variable inductor is as important as a variable capacitor for
>hitting the most desirable matching values. Switched inductor values, in
>this regard, are always compromises,...

   I was about to set pen to paper and order one of the new St. Louis
Tuners Kits based on Chuck's post. Then I saw Paul and Cebik's post
and now am somewhat concerned. Thanks to them for giving the QRP-L
list some hard criteria by which to evaluate tuners. I do not expect
to get my QQ or QRPp until later in January. Perhaps those who have the
subject QQ and QRPp's can help with these questions.

1. Does the St. Louis tuner design have a plexiglas case or wide
   spacing from metal?
2. Does the St. Louis tuner use #16 or larger silver plated wire?
3. Does the St. Louis tuner have a variable inductor?
4. Does the St. Louis tuner design use a Pi-Net config.?
5. Does the St. Louis design sustain component Q througout?
6. Will the St. Louis design stop unattenuated harmonics that otherwise
   are "received" by VCR's, televisions and stereos from many QRPers?
7. How does the "delta" compare on the St. Louis Tuner design?

Maybe Chuck, Paul, or cebik can enlighten us.

happy holidays,

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