[TenTec] ant

[Rick - NJ0IP / DJ0IP]

The big problem now days Jerry is that most of them you find at the flea
market look "fair" on the outside, but if you open them, you close them real
quick and walk away.
I've seen lots of melted coils in the 275w version, and most everything
inside is generally so corroded, it looks like you would have to sand-blast
it to get it to the state you would want.

Time has taken its toll on most of these units.
I highly recommend never to buy one of these sight unseen.

If you can find a clean one and only need a couple of bands, they are
excellent boxes.
If you expect them to match any and everything across all of our HF bands,
you will be very disappointed.
They simply do not live up to their reputation.  Not at all.

73
Rick

-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of Dr. Gerald N. Johnson
Sent: Friday, January 14, 2011 3:05 PM
To: tentec at contesting.com
Subject: Re: [TenTec] ant



On 1/14/2011 1:05 PM, Rick - NJ0IP / DJ0IP wrote:
> These are not as good today as their reputation was 40 years ago.
> The reason is, we've got more bands to match today, and our transceivers
demand darn near 50 Ohms.
>
> The models were 275w and 1KW.
> I had the KW version about 45 years ago.
> Bought the small one about 2 years ago and didn't keep it long.
> The little MFJ-974B (for under $200) was far superior to the Viking in its
matching range.
> Had the two side by side and used them with several different Openwire fed
antennas.
>
> With the mods Jerry did to his Viking, they will match just about
anything.

My first "Johnson Matchbox" was not made by E.F. Johnson, it was made by 
G. N. Johnson, that is ME. It will match most anything from a short to 
an open and I've used it to test twinlead that way.

Were I to have to use an E. F. Johnson Matchbox, I'd be tempted to 
change the circuitry making the link effectively variable with a series 
variable capacitor on the link ground, maybe change the differential 
caps to a switch selecting half a dozen secondary coil taps. I might 
have to add a switched padding capacitor for the secondary tuning 
capacitor after removing the differential caps. Then maybe I would 
prefer to invent a totally different scheme from all that have been made 
and that are on the market including automated remote control and 
coverage from 500 kHz (maybe 135 kHz) through 146 MHz.
>
> A much better box is the Annecke, which L.B. Cebik compares (very
favorably) to the Johnson in his article about link coupled tuners.
> The Annecke had more taps, especially on the TX side, as well as an
additional variable capacitor on the TX side.
> It was also available in two versions; 200w and 1KW.
>
> 73
> Rick
>
>
73, Jerry, K0CQ
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