Charles Kadesch wrote:
: Jim:
: A good way to use an unbalanced tuner with a balanced feed line
: is to use a balun on the tuner input and "float" the RF ground
: of the tuner.
I would advise against this. Although it will provide "better" balance, an
unbalanced T or L style tuner is just that, unbalanced. Doing this can put RF
on the tuner controls and metal case.
The best approach I have found for using unbalanced tuners with balanced
feedlines is a coax choke balun after the tuner. This keeps the RF out of the
shack, balances the feedline, is low loss and doesn't cost much.
To make one get a piece of 3" to 5" OD PVC pipe. Close wind 30 feet of RG-58
solid poly dielectric coax on the pipe(don't use foam dielectric). Put a coax
connector at one end and a couple of connectors spaced for your balanced line
on the other. That's it. Works great, and low loss on HF for reasonable
SWR's. Good 80 to 10 meters probably OK on 160.
Hope this helps.
---- 73 de KA0GKC Claton Cadmus E-mail cla@spacestar.net TCP/IP ka0gkc@ka0gkc.ampr.org Ask me about the Minnesota QRP Society! http://www.spacestar.net/users/aplitech/mnqrp/
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