Dare I ask about the "SEM TRANZMATCH " I am only
using 1900 watts
On Fri, Feb 18, 2011 at 10:16 AM, Steve Hunt <steve@karinya.net> wrote:
> What Rick said, plus: there was a higher power version produced - the
> KW109.
>
> This quote from G3RZP on another forum:
>
> "The KW109 design is not well suited for really high power - say above
> 500 or 600 watts. All the Z match type tuners have the problem that the
> working Q is totally uncontrolled, so some antennas can lead to very
> high voltages and circulating currents. This is why the KW109 was
> produced - an uprated KW107/ KW E-ZEE match. These couldn't the handle
> the KW1000 linear amplifier output into many loads - the KW1000 has a
> pair of 572B with 2400 or so on the anodes. Even the KW109 had problems
> when paired with a KW1000 and some antennas.
>
> I was development engineer at KW back in the 1970s, so I learnt some of
> the weaknesses in the products."
>
> But, if you don't exceed its capabilities and you can live with swapping
> the ladderline between the two sets of terminals, it's OK.
>
> Steve G3TXQ
>
>
> On 18/02/2011 17:51, Rick - NJ0IP / DJ0IP wrote:
> > Tom,
> >
> > First of all, if I say "yes", Gerry will jump in my case! ;-)
> >
> > This is a clasical Z-Match - the 2-coil version.
> > It is the high power version built about 30 years ago (or more).
> > It was designed for openwire from the get go and is pretty good for
> matching
> > typical open wire antennas.
> > Like the Viking, it adds selectivity, which is useful for the receiver
> and
> > for suppressing harmonics.
> > However with today's good receivers (the good ones), you don't need it
> for
> > that reason.
> >
> > It has no bandswitch, so that is one less source of trouble.
> > Instead it has two sets of connections for the openwire.
> > You have to move the feedline back and forth to change from 80/40 and
> > 20/15/10.
> > However, if you have some wild impedances, it can happen that you need to
> > use the other input - generally only true when working 40m or 20m.
> >
> > It also tunes the WARC bands, matches them quite well.
> > Which input 30m uses depends on the antenna. Can go either way.
> >
> > Sounds good up to this point.
> >
> > However, when you get impedance extremes, this box has an awful lot of
> loss.
> > They were condemned by many people because of this.
> > As long as you know that and make sure your antennas are never more than
> > about 1000 Ohms, they work OK.
> > You do that by changing feedline lengths.
> >
> > The answer to your question depends on the price.
> >
> > A better box in my opinion is the big MFJ Symmetrical matchbox.
> > If the auction price comes anywhere close to that, go with the MFJ.
> >
> > Maybe Gerry has some other reasons why not to use a Z-match.
> > I'm sure Steve is quite familiar with it; probably more than the rest of
> us.
> >
> > At the end of the day, there is theory and practice.
> > I have the low power version, the KW EZEE Match, and I'm not parting with
> > it.
> > I haven't used it for 20 years, but I'm keeping it as a backup
> symmetrical
> > matchbox.
> >
> > When I was using it regularly, I used it with:
> > - 2x 13m doublet
> > - 2x 17m doublet
> > - 2x 20m doublet
> > - 84m Horizontal Loop
> > - 42m Horizontal Loop
> > - Vertical Dipole (2x 5m)
> >
> > Our club(s) turned in lots of good field day results with these antennas
> > (especially the loop), using that Z-match.
> > I had lots of successful mini-expeditions with these combinations.
> >
> > There are better matchboxes.
> > Some are expensive, others are not to be found (because nobody parts with
> > them [think "Annecke"]).
> >
> > 73
> > Rick
> >
> > -----Original Message-----
> > From: tentec-bounces@contesting.com [mailto:
> tentec-bounces@contesting.com]
> > On Behalf Of tom stewart
> > Sent: Friday, February 18, 2011 11:48 AM
> > To: TenTec@contesting.com
> > Subject: [TenTec] KW 107 Supermatch
> >
> > Is this a good tuner for balanced lines? Is it worth pursuing?
> >
> > Thanks- Tom N7ESE
> >
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--
"No matter how fast you miss, you still lose."
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