[TenTec] Tuner types and efficiency

[patents@dx0man.prestel.co.uk]

I agree entirely. I used a massive home brew "ultimate transmatch" for
several years before I got my TenTec 253, which uses the same basic
L-match configuration as in the 238 (which I could not get over here
in UK at that time. The 253 came from a close-down sale and I made a
250 mile dash thru the night to be first in the queue). I also have
an Omni-V, and a Hercules II, which is out of action with a vacuum
relay driver problem right now.

The TenTec L-match works extremely well; I use it to feed a Centaur
balun thru 20 ft of heavy coax, then 70-80 ft of ladder line to an
inverted V dipole at 55 ft for 40m. I use it on all bands 40 thru
10. OK, things change when the ladder line gets wet, but the overall
efficiency beats the heck out of using 100 ft plus of coax for the
same job. How do I know ?? Just look at my log book...

The need to adjust the match from time to time is a minor issue
compared to the performance improvement I got. BTW; Don't sell the
cheap plastic ladder line stuff short. Get the multi-stranded 14 or
16g stuff. It works great, tho I'm well aware that the 40m dipole is
not exactly the best for 20 thru 10m. The mismatch on 20 and 10 is
horrific, but I have used the TenTec L-match at the 500 watt level on
these bands without any sign of arcing, etc. (The Centaur balun has
not caught fire yet, but I'm glad its rated at a KW plus !! I use it
to avoid bringing ladder line thru a nine inch brick wall).

On 40/30, the 40m dipole is excellent. Its especially good on 30m.

Getting a 1:1 SWR is easy, but naturally needs a bit of care on 10 and
20 where the settings are sharper. This L-match has kept me on the
air, on most bands, in all weathers. I'd go for the 238, a load
of ladder line, and then keep a detailed record of the settings for
each band/antenna, wet and dry.

73 John G3JAG.

On 23-Jan-99 rohre wrote:
> 
> Duane and the gang,
> Matching networks have been discussed and wrung out pretty well
> over on the
> QRP reflector, because every dB counts over there!
> 
> Well, someone there started testing tuners, ATUs whatever you want
> to call
> them.  And there were a series of tests also published in QST.
> 
> The Ten Tec tuner having an L network is going to have one less
> component to
> have losses.  It has already been pointed out, that generally it
> only has one
> valid setting for a frequency, unlike the more numerous Tee tuners
> that can
> have one setting of lower loss, and another setting with more loss.
> The
> matching device tests show in general that the L network is the
> lowest loss of
> all antenna matching devices.
> 
> It should be a good choice to choose the Ten Tec unit.   I agree,
> the chart
> for quick look up is needed for any matching device.  Humidty
> change, ice,
> rain, etc. change the parameters of the antenna and feed line you
> are matching
> to your rig from one operating time to another.
> 
> 73, Stuart K5KVH
> 
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----------------------------------
E-Mail: patents@dx0man.prestel.co.uk
Date: 22-Jan-99
Time: 13:06:31
John Crux
Consultant in product forgery - Asia and
Africa

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