Pete Smith wrote:
>At 09:33 AM 11/24/2008, jimlux wrote:
>>Pete Smith wrote:
>>>What am I missing here. You need to cover 8 bands - surely a set of
>>>switched L networks, including several for band segments on 160, 80 and
>>>40, could be built for much less than any automatic tuner capable of
>>>handling the power. You're not looking for continuous coverage 1.8-30
>>>MHz, after all.
>>>73, Pete N4ZR
>>A couple years ago I ran through a design exercise on just this approach,
>>and it turns out that it's about the same, either way. The typical L
>>network autotuner has 7 or 8 L's (and their relays) and 7 or 8 C's (and
>>their relays) (the SGC with a pi network has more C's, total).
>My point wasn't to run an economic exercise here, but to suggest a DIY
>approach. Besides, the commercial tuners all involve enclosures, fancy
>control systems, and (gasp) profit.
There was a book by Vertical Antenna Book by Capt Paul Lee N6PL
published by CQ Communications back in the 80's which featured numerous
examples of homebrew matching networks with relays for multiband
coverage. If you already have a big collection of wide spaced
breadslicer caps that you been collecting for years for no other reason
than "they look cool" (speaking from experience here), then homebrew
might be a good option. Huge diameter copper shouldn't be needed for the
inductors if you are just doing 160, 80, and 40 meters.
73, Mike W4EF....................
TowerTalk mailing list