I had a very bad experience while trying to help a friend with
his motor home mobile installation of an SGC tuner. basically,
the problem is as folows:
1. If the tuner is set up, tuned to a fixed set of memorized
frequencies and operated only on the memorized frequencies,
it works OK. In this mode, it isn't repeatedly hot switching
the inductors.
2. If the tuner is used with a random wire type antenna and
required to frequently retune due to frequency changes or
band changes to non-memorized frequencies, it soon burns up
some of the inductor switching relay contacts and eventually
becomes unable to tune the wire.
We had the unit either replaced or repaired by SGC at least three
times before giving up. SGC became increasingly difficult to
deal with as time went on. They eventually refused to help with
this unit any more. The rig was an ICOM 736 with no amp. the
antenna was a 270 ish foot long piece of wire averaging 30 feet
or so off the ground.
I think that they could easily prevent this problem by detecting
forward power during tuning operation and sending an ALC voltage
back to the rig to prevent operating the inductor relays when
more than a few milliwatts of RF is present. But by the time I
thought of this, SGC was no longer responding to us. I suppose
this arrangement could be outboarded without a lot of trouble.
But, IMHO, it should be built into the unit and not the
responsibility of the owner.
The last unit we fried took a lot longer to kill. But that was
because we had been limiting the RF out to an absolute maximum of
somewhat less than 10 watts when tuning was enabled. Eventually,
John (KB7RFE) got a nice roller inductor manual tuner which has
performed flawlessly ever since. Once he got over the idea that
tuning manually was "difficult" and discovered that it is
actually very simple, he wondered why he was worried about it at
all. Of course, for a remote application, the considerations are
very different.
73, Eric N7CL
To: <towertalk@contesting.com>
>Date: Thu, 04 Feb 1999 06:53:24 -0600
>From: Richard Thorne <rthorne@tcac.net>
>
>Does anyone have any experience with the 500 watt auto tuner by
>SGC? There expensive but it would be a nice addition to my 500
>watt remote controlled station. I'm thinking about putting up
>an inverted L for 160/80 and the tuner would handle the swr
>variations from SSB to CW etc and also get me on some of the
>warc bands.
>
>If you have one of the other SGC tuners I'd like to hear from
>you. I'm guessing their operation is the same other than power
>handling.
>
>Thanks in advance.
>
>--
>73,
>Richard Thorne - N5ZC (Ex. KA2DSY, N2BHP, WB5M)
>Amarillo, TX
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