ABOUT BUYING an ANNECKE MATCHBOX
THIS PAGE PERTAINS SPECIFICALLY TO THE SYMMETRICAL KOPPLER (the improved Johnson Viking Matchbox). BEWARE: most Annecke matchboxes built were ASYSEMMETRICAL, not designed for matching openwire fed antennas.
ABOUT BUYING AN ANNECKE SYMMETRICAL KOPPLER:
Forget it. You will win Mega Bucks before you find an Annecke Symmetrical Koppler for sale.
There were not very many of them ever built and most people won’t sell theirs; it only changes hands when the OM dies.
About once or twice per year one will be listed the German “CQDL” Magazine but even if you call one minute after the mag arrives in the mailbox, the Annecke is already sold. Seems there are enough people with prior access to the want ads in the mag.
As for the big one, the 1 KW version, Annecke only built 20. I built one from spare parts because he had already sold his last and was not willing to purchase another 20 cabinets. He didn’t think he could sell that many again. Today he probably could.
The Annecke Symmetrical Coupler was probably the best symmetrical matchbox, but mainly in terms of its matching range. It could match a very broad impedance range, even on the WARC bands. If you can keep your antenna inside of a range from 100 to 1500 Ohms by playing with lengths of the dipole and feedline, other match box designs will work just fine.
If you must match outside of this impedance range, then there are still other solutions. In another section of my web, I show examples of the work done by Alfred, DF2BC. He has designed several matchboxes for matching very low impedances relatively efficient.
I don’t own or use an Annecke today. Instead I use a Ten-Tec Model 238-B (-A and –B are identical except for color of box). And of course the newer Model 238-C is the same but has a better watt meter.
The L-Network is the best alternative because of its low insertion loss.
DO NOT USE THE BALUN INSIDE OF THESE TUNERS; IT IS CRAP!
THEN: (IMPORTANT) use a big home-brew 1:1 balun (no exceptions). I don’t know of anything else you can buy anywhere that I would recommend.
See: http://www.dj0ip.de/balun-stuff/tuner-baluns/ for some theory and links to Gurus who confirm this.
- For QRP up to 30w, wrap 17 or 18 turns of good quality RG-174 coax onto an FT-140-43.
- For up to 300w, wrap 17 or 18 turns of GOOD QUALITY MIL-SPEC RG-58 onto an FT-240-43.
- For 500 to 1000, glue 2x FT-243-43 together and wrap with RG-142 Teflon insulated coax.
- For 1500w, glue 3x FT-240-43 together and wrap with RG-142.
For gluing, I use fast-drying 2-component epoxy and once it is mixed I just put 1 drop of glue every 90 degrees onto one of the toroids, press them together and then carefully lay a small stack of books on top of them during the drying period.
This will enable you to have good common mode impedance, even when matching very low impedances.
If you happen to have a band where the impedance is too high, you can insert a 4:1 balun between the feedline and your [External] Tuner Balun. But do not leave it in for helping with the impedance when it is not absolutely necessary. As long as the tuner will tune to low SWR without the 4:1, do not use it.
The 4:1 can be a simple Ruthroff (voltage) balun. Use an FT-240-61 core (regardless of power) and then wrap it with 10 turns of bifilar or twisted pair Teflon-insulated wire (18 AWG for up to 1000w), 12 turns for 40m (and above), and 14 or 15 turns for 80m.
If you wrap it for 80m, it works fine thru 15m but SWR rises on 10m.
(for 100w, use FT-140-61; for QRP use FT-114-61; use thinner wire / 22 or 24 AWG)
If you can avoid it, do not use a 4:1 balun at all.
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