[AMRadio] Balanced tuner

[Mike Sawyer]

Nice website Mark,
	I went and book-marked it. DJ0IJ is very articulate in his reasons and methods. I'm going to be reading over some of the remainder of his site to glean any other useful information. With regards to the 'Matchbox', he advocates adding a 3rd capacitor in series on the input side of the 'box'. One has to be reminded that capacitor needs to be as large, (voltage wise) as the final's 'tune' on any 'boat-anchor' or amplifier! Component selection must be made accordingly. Remember the original Johnson KW Matchbox was designed at the time for a 1KW input. The closer you are to a match on the frequency of selection, the lesser your chance of 'fireworks!'
	Of course, your mileage may vary!

Mod-U-Lator,
Mike(y)/W3SLK



-----Original Message-----
From: amradio-bounces at mailman.qth.net [mailto:amradio-bounces at mailman.qth.net] On Behalf Of Mark Foltarz via AMRadio
Sent: Friday, April 27, 2018 11:36 PM
To: CL in NC; amradio at mailman.qth.net
Subject: Re: [AMRadio] Balanced tuner

Charlie,
  I have a Johnson KW matchbox that I picked up years ago.When I got it it was a junker. Lots of extra holes and  the cabinet was ugly.
I believe it was used for a magazine article some years back where the tuner had 160 meters added.
I also had trouble matching  various dipoles with it. Some worked great while others would not.
I found this link http://www.dj0ip.de/antenna-matchboxes/symmetrical-matchboxes/j-viking-upgrade-1/
Since the match box was sort of ugly  to begin with I took the plunge and did the mods.
Wow, the improvement is significant. The tuner actually works well now. As well as any balanced tuner I have seen -including my TMC TAC-1,
Just  a thought 
de KA4JVY
Mark