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FriMatch antenna tuner

When I passed my F(ull) lincense I was allowed to work on more HF bands (10m..160m) then the standard (partial) 10/20/40m bands which I was allowed work with an N(ovice) license.

For best preformance these new bands would need different antenna's but do through the size of my back-yard I'm for now stuck with me allready perfectly working 10/20/40m EndFed antenna.

So I start experimenting and created different kind of antenna tuners to allow my endfed got tuned on the bands I mised in the configuration. Or atleast to be able to work on 80m, 30, 17, 15 and 12m bands. After a while and various models who didn't satisfy me, I found the FriMatch configuration as desribed by PA0FRI. ( http://pa0fri.home.xs4all.nl/ATU/FRImatch/FRImatcheng.htm )

Image (C) PA0FRI

This tuner configuration allowed me the tune my EndFed on everything between 80 and 10m without any problem (ok there is some loss but a 1:1 match can be done).

The variable capacitors where not exactly the 470pF models, but had only one 420pF, two 20pF and one 380pF section. Putting the two 20Pf and the 380pF section in parrallel I was getting close. I used a T200-2 torioid as coil and until today the all seems to work perfect.

I also added a SWR indicator in it which can be found in variouse models of Z-Match tuners like the ZM-2 (see : http://www.w5usj.com/zmatch.html ) but used a little bit heavier resistors (two 100 ohm 3 Watt in parallel) allowing me to tune with my set minimimum of 5 watt. The bridge itself gives a -6dB reducing the output with a nice amount.

 

 

 

 

 

 

 

 


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