Motorola PAs use similar straps which are shaped like an OMEGA symbol, so they're called omega straps. You don't need much of a bend in them, just a slight mound, perhaps 1/8 inch across. The flexible solder-wick idea is easier to deal with; in a snap you could also use some braid from a piece of RG174, but make sure there's an untinned area in the middle that's still flexible, otherwise it will just crack and fail again. The boards don't move very much, but if you use a flat piece of metal to bridge the gap, that WILL either break apart or tear one side off the solder.
The amount of material you use to span the gap could be critical in some applications, so the shorter the better, Of course, that conflicts with the idea of having plenty of material to flex, so perhaps 1/16 inch or less might be advisable. These straps are visible if you look carefully enough, in the upper right corner, between the two screws, of most of the photos in this article: http://www.repeater-builder.com/ge/m2-uhf-pa-repair/m2-uhf-pa-repaired.html Bob M. ====== --- Jim Brown <[EMAIL PROTECTED]> wrote: > Joe, that common problem you are remembering is the > strap between the final and the input of the low > pass filter. The fix is the so called 'inchworm' > mod which is described in past posts and at the > repeater builder site, as I recall. It involves > putting a piece of solder removal braid between the > final output and the input of the low pass filter to > prevent the heat expansion from separating the > solder bridge. Leave a small part of the braid > unsaturated with solder and bow it slightly up and > back down 'inchworm' style to allow the epansion to > take place with no losl of contact. > > 73 - Jim W5ZIT > > Joe <[EMAIL PROTECTED]> wrote: > I'm slowly going through all my repeater > stuff here and have a problem > with the 100 watt UHF PA PL19d424895g32. No output. > I checked the > exciter into another identical PA and it works fine. > Drive is a little > low, 100mw, but it drives the other identical amp > just fine. The bad PA > draws 5 amps when keyed, the power control pot > varies this current from > 0-5 amps. No output out of the PA. This was a > working repeater that is > being tested on it's original frequency of a > 45/1456Mhz split. No parts > look burned or discolored. The straps between the > boards look fine, no > cracks. I touched them up with and iron anyway just > to check. My first > thought is to check the output of the 40watt stage. > > Any words of wisdom before I tear into this beast? > Any ideas? I seems > to remember reading about a UHF PA common problem > but can't find it in > any of the reflector archive messages. > > 73, Joe, k1ike ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
