Looking for Auto-Balanced Tuner

[jmeade]

I thought of feeding the coax inputs of two small tuners (like the MFJ16010)
from the output of a 1:1 balun (like the BL1). Use banana plugs to connect
the balun output to the center pin of the input coax connector. Connect the
tuner grounds together and - presto - a balanced tuner!  This may work with
two auto tuners also - assuming that each tuner is set to the same L/C
settings to maintain balance.

I am still wishing for a truly balanced auto tuner with one set of
capacitors and two sets of inductors.

72,

John W2XS
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[Richard Thorne-2]

A little pricey but exactly what your looking for.

http://www.hamware.de/

Rich - N5ZC

---- [hidden email] wrote:

> I thought of feeding the coax inputs of two small tuners (like the MFJ16010)
> from the output of a 1:1 balun (like the BL1). Use banana plugs to connect
> the balun output to the center pin of the input coax connector. Connect the
> tuner grounds together and - presto - a balanced tuner!  This may work with
> two auto tuners also - assuming that each tuner is set to the same L/C
> settings to maintain balance.
>
> I am still wishing for a truly balanced auto tuner with one set of
> capacitors and two sets of inductors.
>
> 72,
>
> John W2XS
> _______________________________________________
> Elecraft mailing list
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> You must be a subscriber to post to the list.
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[Don Ehrlich-2]

I built my own.  You can see a 'brassboard' of it on my web page
http://www.qsl.net/k7fj/

The tuner now uses a BasicX PIC which has far more memory available than the
Basic Stamp PIC.  The tuner works great at 500 watts when driving my 600
foot horizontal loop through ladderline.

I plan to order a K2 case next week and will be building the tuner into the
new case this winter.

There have been changes in software.  I no longer use it as an autotuner
because I ran out of memory for that function but it could still be
implemented with a little programming effort.  I found that autotuning is
just not necessary.  The tuner is designed for manual tuning using
inductance and capacitance up and down buttons and, once a good match is
achieved manually, L and C are stored in memory for that particular
frequency.  This can be done for either of two antennas (selectable from a
menu).  The C is connected either to the output (antenna) or input sides of
the inductors by a menu sellection and this is remembered (and retrieved
automatically) for each frequency and each antenna.

The tuner is connected to the com port of the K2 and its settings (L, C, and
input/output C connection) are automatically changed whenever the frequency
of the K2 is changed.  It is a completely 'hands off' tuner.

Don K7FJ

>
> I am still wishing for a truly balanced auto tuner with one set of
> capacitors and two sets of inductors.
>
> 72,
>
> John W2XS
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com 

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[Ian Stirling, G4ICV, AB2GR]

On Friday 08 December 2006 13:32, [hidden email] wrote:

> I am still wishing for a truly balanced auto tuner with one set of
> capacitors and two sets of inductors.

  I have an SG-231:  its manual states that it can be used
in a loop, one end to the 'hot' terminal and the other
to the 'ground' terminal.
  Would there be a significant difference using a balanced tuner?

Ian, G4ICV, AB2GR, K2 #4962
--
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[Thomas Beltran]

 



  I have an SG-231:  its manual states that it can be used in a loop, one
end to the 'hot' terminal and the other to the 'ground' terminal.
  Would there be a significant difference using a balanced tuner?

Ian, I also have the 231 and it is an unbalanced tuner.  I tried it with the
Cobra Extra light Jr. on 80 meters and had RF all over the place.  I bought
the MFJ manual balanced tuner, and problem solved.  The 231 is actually
designed for long-wires or verticals.  It will work on loops and all, but
with mixed results.  

Now, the 231 is in my trunk with a very short lead to a 102" whip and it
works very very well.  I think Palstar has some type of auto balanced tuner.
Tom W6EIJ

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