I believe there is a conversion article on the repeater-builder web site that gives a method of using the antenna switch transistor on the station control board to switch the F1 lead to ground on PTT.
Milt N3LTQ ----- Original Message ----- From: "Laryn Lohman" <[EMAIL PROTECTED]> To: <Repeater-Builder@yahoogroups.com> Sent: Saturday, January 20, 2007 10:38 PM Subject: [Repeater-Builder] Re: Micor Base Station Amp Problem-CURED > Hi all, I just found the problem with this transmitter, problem > described below. To force F1 at all times on the exciter, I jumped > from the channel element pin to Switched A-. NOT a good idea. Doing > that apparently creates a ground loop and an oscillation at around > 50kc. It did this with two different exciters. Moving the ground to > A- completely fixed the problem. > > This was driving me NUTS. There probably is a proper place to force > F1, but for now I'll leave it on A-. It keeps the channel element > active all the time, which is annoying during bench work while > monitoring on-channel. > > Laryn K8TVZ > > > --- In Repeater-Builder@yahoogroups.com, "Laryn Lohman" <[EMAIL PROTECTED]> > wrote: >> >> Hi all, I have a base station that came with a TLE1703 amp. It was a >> part of Medcom equipment at a local hospital. I took it out of >> storage last week, and it keyed up fine, with about 40 watts out. I >> also have a TLE1713 amp from another station, and after quickly >> swapping it with the 1703, it too seemed fine with about 70 watts out. >> >> After moving things around in the cabinet last nite, and having the >> 1713 amp installed, I noticed an arcing noise from the amp. Keying >> the amp with the cover off revealed arcing at random places near the >> negative DC bus, and the 4.7uf capacitors getting very hot. Since >> this amp shows evidence of being serviced at some point, I decided to >> move back to the original 1703 amp. This amp is very clean inside and >> shows no evidence of ever being serviced. This amp too will arc with >> the capacitors getting very hot after only a few seconds of keydown. >> >> So what could be the problem. I am using a good wattmeter and load. >> Is there something in the antenna network after the amp that could be >> bad? I measured the SWR looking into the antenna network with the >> load on the other end and it shows 2.1:1. Isn't that a little high?? >> Or maybe the caps are simply old and dried out? >> >> Where do I look for the problem? >> >> Laryn K8TVZ >> > > > > > > > > Yahoo! Groups Links > > >
