Re: [Repeater-Builder] Hamtronics exciter

[Steve Grantham]

Thanks Bob & Greg!  As one might imagine, I really need one more project to do around here ;) I had looked at the mod Kevin posted, and even looked for the parts, but none were readily available. After that, I started giving serious thought to a wholesale change out to MASTR II radio gear... I am getting my M2 stuff together, but I'll still be left with the Hamtronics stuff with the crystals. Thanks for the tips!   73, Steve   ----- Original Message ----- From: Gregg Lengling To: Repeater-Builder@yahoogroups.com Sent: Wednesday, April 14, 2004 2:30 PM Subject: RE: [Repeater-Builder] Hamtronics exciter   I've done the FM PL mods to this type of transmitter to get direct FM for CTCSS injection.  The modulator on that exciter will not handle CTCSS so the mod is required for a nice clean PL.  It's a rather simple mod with only a few parts and is documented on the RepeaterBuilder website.     Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible.   -States: The Bene Gesserit View -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, April 14, 2004 2:05 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Hamtronics exciter   Hi Steve,     Does anyone think it would be feasible or practical to modify the TA-51 to implement an LC phase modulator?  Just how easy or how difficult might that be?     You could use a varicap, a tunable inductor, and a capacitor to build a circuit that's resonant at the crystal frequency, and that's fairly easy. But such a circuit also generates an AM component that must be removed, so another transistor stage is needed for isolation. That probably means you're up to a little perf-board ('blob') addition to the exciter.   BTW, we think that the GE PM exciter suffers from a little of the same insufficient isolation problem, but that's another rainy-day investigation.   Incidentally, the RC version of a phase modulator is sometimes called a reactance modulator, and the LC version is called a tuned circuit modulator.   73, Bob, WA9FBO Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/   To unsubscribe from this group, send an email to: [EMAIL PROTECTED]   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.