----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, August 17, 2008 11:56 AM Subject: RE: [Repeater-Builder] TX-RX 66-88 MHz Cavity to 6 Meters
>I had a few Sinclair LB cans (from a LB hybrid ring duplexor) some years >ago that were in the 30-40MHz range. They had a "can" about 12in long by >about 3 inches in diameter silver soldered to the moveable end of the >resonator. Removing these with an acetylene torch raised the frequency by >about 10MHz (ie 35MHz went to 45MHz) in the center of its tuning range. > > Adding such a "can" or tophat capacitor to your cans should lower their > frequency by the same percentage. I also had a high band VHF can that > tuned the aircraft band that had a similar can on it except that it was > only 2in long. More like a cup. Removing that raised the range to > 132 -150 or more. > > The diameter of the added "can" appeared to be about 2-1/2 to 3 times the > diameter of the resonator. The length would be whatever was required to > achieve the end result. > > Any of these tophat capacitors will lower the Q of the can but at 6m you > have lots of spare leeway with 1 mHz separation. > > Burt VE2BMQ > > >>Has anyone ever converted a 66-88 MHz Tx-Rx BpBr cavity for us on 6 >>Meters? I came across 2 of these and I could get them down to 57 MHz >>but that was about it. >> >>Thanks, >>Joe - WA7JAW >> >> > > ------------------------------------ > > > > Yahoo! Groups Links > > >
