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I sure enjoyed the review of the Palstar tuner, sounds like a nice one.
Personally though,. I have never liked tuners with air-variable capacitors.
They are prone to arcing over as John has noted, they collect dust in-between
the plates and for an adequate voltage rating they just take up too much
room. To do it right I recommend using vacuum-variable capacitors in a tuner.
They are sealed, they stay in like-new condition inside, and you can find
them at 10KV voltage ratings at reasonable prices on eBay, in the $100-$150
price range. When you consider the new cost of a vacuum variable capacitor
today in the $1000-$2000 price range and up, the ones on eBay are a
tremendous bargain. 73 Todd Roberts WD4NGG .
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To: <amps@contesting.com>
Date: Tue, 19 Jun 2001 07:33:47 -0500
Subject: [AMPS] Review of Antenna Tuner from Dayton
From: Jon Ogden <na9d@speakeasy.net>
To: Amps Reflector <amps@contesting.com>
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Hi all,
Well, it might not be specifically amplifier related, but I thought I'd let
you guys now a little about the new antenna tuner I picked up at Dayton.
Yeah, yeah, I know - some of you don't like to use tuners and load the amp
directly into the antenna. Personally, I don't like that approach as I'm
not able to accurately measure power under high SWR and I also like the
added harmonic suppression of the tuner.
Previously, I had an old Heathkit roller inductor tuner. It worked fined
for the most part with full legal limit, but would sometimes have arcing
problems on the load cap. The biggest problem was with my 80m dipole. It
is cut for 50 Ohms around 3.6 MHz and there it gives a great match.
However, as I move up in frequency, the match is very narrow. I start
getting about a 3:1 SWR around 3.75 MHz and it gets worse from there.
The Heathkit would arc even at power levels under 1000 Watts. I even tried
removing one of the offending plates from the capacitor in the hopes that
the larger air spacing would help. It didn't and in fact, made other things
a little worse. So given this background I decided to look at antenna
tuners at Dayton.
My first stop was to look at the Ameritron/MFJ/Vectronics units. After all,
they are the most prolific tuners out there right now. Upon looking at all
these units, I found that the plate spacing on their caps were no better
than what my Heathkit had. Even their highest power units had caps with the
same spacing. It is interesting to note that later I noticed that the
Ameritron tuner rated for 1200 Watts has larger cap spacing than the ones
that are more expensive and rated for higher power!
So I figured, buying one of these, probably wouldn't help at all.
After this, I began working my way over to the booth of another company that
I knew sold tuners - Palstar.
I got to the Palstar booth and to my delight their tuners looked absolutely
awesome. Plate spacing was at least twice and possibly three times larger
than anyone else's. Construction looked to be of an excellent quality and
the units were rated at 3KW or greater (if memory serves me).
They weren't cheap. The AT4K with a built in antenna switch, LED bargraph
and so forth was over $900. However, they were selling the AT4K-BAL which
has a single input and a single output (either balanced or coax) and none of
the electronic metering. This unit sold for around $700. Since this
configuration was similar to the Heathkit I had, I decided that this was the
tuner for me. First I wasn't going to buy it but wait a couple of months.
Then I decided, "What the heck!" So I went and bought the unit they had on
display.
Well, upon getting the tuner home, I immediately went to 80M, tuned up and
VIOLA! - NO ARCING!! So, I was like, COOL! I've used the tuner on just
about all bands now at full legal limit and it works just great. It will
even tune my 80 m dipole on 160 m which is something my Heathkit wouldn't
do.
My only complaint about the unit is that the roller inductor is a little
stiff and hard to turn in some spots, but that will probably get better over
time.
It isn't much bigger than the Heathkit unit so it fit right into my station
set up with no problem.
I am VERY, VERY happy with this purchase and would recommend the Palstar
tuners to anyone. I think they are an excellent product for the price. The
construction is much better than the MFJ/etc. units I saw.
Also, Palstar makes power meters. They have a very reasonably priced unit
that is a 3KW unit that is a pseudo peak power reader. It is about $75.00
or so. A much better price than similar units from MFJ/Diawa, etc who may
not even make a 3KW meter or would charge well over $100 for it. Sure, it's
not as good as a Bird, but it is a very nice unit.
Palstar's Web Page is www.palstarinc.com
73,
Jon
NA9D
-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)
Member: ARRL, AMSAT, DXCC, NRA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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