The AM Forum

Decided to make use of the K3L antenna tuner to keep the dust away and make it easier to change bands. Made a DPST switch out of an old 50 Amp knife electrical disconnect. Hooked the open wire line to the common, the K3L tuner to one side and my existing station tuner to the other side. Both tuner inputs can be selected using the garden variety coax switch (that's cow-axe if you live near Phila.). Made it through the week on 75 no problem. One tuner set for 40 and one for 75. QSY time cut way down. Yesterday afternoon set the existing tuner up for 160 which required fabrication of a new fixed parallel coil to replace the roller inductor robbed for the K3L tuner. That went a little too well. I actually managed to guess the correct tap on the first try! System now delliveres 16 R.F. Amperes into feeders at legal limit power out (antenna proper is only 120' long dipole). Whoopie! Back across the basement to check a few more things. Left the thing on the air for 5 minutes at 1000 Watts steady carrier while writing settings down. Noticed a 5% power drift. Bad sign. The amp which is in use here never drifts. Shut everything down. Back over to the Northeast side of the dungeon where the tuners live. Something smells a little warm. What is it? Hmmmm? Can't tell. Just know it's not the Xyl making dinner 'cause she isn't home.

Here is what was cooking. Guess the insulator block is lossy at R.F. after all. Even though it survived the test on 40 metres.

Guess so dave, is all hope lost or can she be rebuilt with a teflon or thick lexan plenum?

Considering Plexiglass. I'm too cheap for Teflon.