Having two of those old Johnson Matchboxes currently in use to feed two
loops, I have often wished that someone would manufatcure either these or
other link coupled transmatches.
I have also wondered if it would be fesible to develop such as a kit....or
the parts thereof.
----- Original Message -----
From: "Rick Westerman" <Rick@dj0ip.de>
To: <tentec@contesting.com>
Sent: Wednesday, March 17, 2004 5:48 AM
Subject: [TenTec] Johnson Viking Matchbox vs. Annecke
> I changed the title because this is no longer 80m Loop specific.
>
> Don, I hope I didn't shock you by implying it was something new
> and you had missed it. As Mike pointed out, LB Cebik (W4RNL) has
> done an excellent job of comparing the two circuits in his
> article on Link Coupled Tuners. You'll find it on his web site.
>
> Most people probably won't tell a difference between the two and
> for TEN-TEC users (at least the ones running barefoot) it
> probably doesn't matter whether one runs the original Johnson
> circuit or the Annecke circuit. In fact if you have a good tube
> amplifier, it won't matter either. It's just the hams with
> transistor power amplifiers who will see a great benefit from
> modifying the Johnson to an Annecke.
>
> The Johnson was designed in the days of tubes where every radio
> and amp had a PI-filter in its output. If the matchbox brought
> the antenna's impedance down to 150 or 200 ohms, that was just
> fine because the PI-filter could do the rest.
> Once transistors came along, the need was redefined to tighter
> tolerances. Before we had the WARC bands, it was no big deal
> because it was usually possible to find several lengths for your
> antenna which the Johnson could pull in to almost 1:1.
>
> What Annecke did was make the 50 ohm side switchable and add a
> 270 pF variable in series with the link. With that, you can
> pretty match anything to 50 ohms. The trade-off is that you have
> one more knob to adjust.
>
> So, if you don't have a TEN-TEC and your transceiver requires
> exactly 50 ohms, the Annecke circuit is a little bit better.
>
> LB shows a picture of the insides of the Annecke but he chose the
> wrong Annecke matchbox. He showed the QRP version (200w). I
> have the "real" version. Go to my web site www.dj0ip.de and
> click on the picture at the bottom titled "Home of Orion".
> You'll see the matchbox just above the TFT monitor which is just
> above the Orion. Note the 4 big knobs. The one on the right
> titled "Sender" (meaning transmitter) is the additional variable.
> I've been running both the high power and low power version of
> this matchbox for about 20+ years. However, often in contests
> when I'm running lower power, I substitute a "Differential-T"
> tuner because there's less knobs to tune. For high power,
> nothing beats the Johnson/Annecke circuit.
>
> I wanted to build a second one but parts are difficult to find.
> I was also considering the Z-Match designed by Lloyd, VK5BR.
> I've been discussing the pros and cons with LB. LB felt the
> Z-Match probably will not be as efficient. In the meantime I see
> that he has included Lloyd's Z-match on his web site too. I hope
> someone smarter than me takes the time to measure and report on
> the efficiency of the Z-match.
>
> I've scratched the idea of building another one and will simply
> purchase a used Johnson. One of the OM here on the reflector was
> kind enough to reserve one for me. Now all I have to do is get
> to the states and pick it up!
>
> Finally, I would like to pay tribute to Mr. Annecke who passed
> away a couple of years ago. Altogether, I think he designed
> about 15 or 20 different matchboxes of various sizes and shapes
> and circuits. He sold them as kits, ready built, or just the
> components (which is what I bought). Unfortunately his son who
> took over his business, dropped the line of ham gear because it
> probably was not a lucrative business.
>
> I have all the circuit drawings of every matchbox Mr. Annecke
> produced. If I ever find time to work on my Ham website instead
> of my work web site, I want to exhibit what he contributed to the
> ham community. Right now I can't even find time to use my Orion.
>
> 73
> Rick
>
>
>
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