>"Anybody TDR such a splice?"
You'd be surprised what you can get away with below VHF. W0AIH's
method probably worked fine on 10 m. and down. Not sure if he
soldered or made a mechanical bond. I'd probably want to solder but
I'd worry about melting the foam dielectric if the line were Heliax.
My first thought when I read about Paul Bittner and the soda bottle
was "never underestimate a ham's ability to out-cheap me." Hi hi.
But back to the impedance bump, I once built my own two position coax
switch because I was not happy with the ones made for ham radio, I
wanted a large surface area for QRO, and didn't want to waste a Bird
Coaxwitch on two positions. I mounted UHF jacks on an aluminum box,
and inside mounted silver plated knife switch clips on insulators and
a copper blade to a common jack with everything wired and mounted so
the blade would swing between the two clips. I almost never operate
above 40 m. so I didn't care about an induced vswr excursion, knowing
that on the low bands it would be fine. But I swept it anyway with an
analyzer on one end and a Bird 1.5 KW load on the other. The load is
either 50 or 52 ohms all across HF, can't remember which. I was
amazed to find that the Z through the switch went up one ohm R, 0 X,
somewhere above 20 m. and that was it.
73
Rob
K5UJ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|