EMRFD Message Archive 3620
Message Date From Subject 3620 2009-10-18 15:32:46 Tim Link-Coupled Tuner If you go to "photos" and "N3QE Link Coupled Tuner" you can see what I've been working on in one form or another for a while: a http://groups.yahoo.com/group/emrfd/photos/album/1684596589/pic/1109048190/view">good old fashioned link coupled tuner.
Base board is pine.
Coil support is 1/4" polycarbonate.
Load capacitor is approx 1200pF variable, a really old "Cardwell Condenser" unit.
Tank capacitor is dual 135pF Johnson.
http://groups.yahoo.com/group/emrfd/photos/album/1684596589/pic/1385664770/view">Coilsets are made from 14 gauge hard drawn copper, and threaded through 1/8" polycarbonate sheet for support. The inner (primary) is welded into a cutout of the secondary sheet.
Coilsets are changed out through a 4-banana-plug arrangement.
Largest coilset I have so far is 80M, which is 8.5" long, 3" diameter. Threading the 34 turns of copper through required most of two hours without any little kids running around!
Loads up into my 130-foot doublet fed with ladderline very nicely.
I could imagine trying to make a 160M coilset.