Re: Micor power supply issue Micor Power Supplies should be dirt cheap on the surplus radio market. In some cases a few two-way shops would probably give you a replacement used supply.
I know of a surplus store here in California with a number of new in the box Micor Power Supplies for sale cheap. But the shipping would kill the good price. You can replace the filter caps easy enough... The replacements can don't have to be exact values... Be advised that used, surplus and New Old Stock Capacitors can be tired, problematic and should probably be pretested for proper operation. Someone with a Sencore LC-102 or similar type analyzer is handy to know. As always, sometimes a real deal isn't... cheers, s. RIP: HSC Electronics in Sacramento, CA - Closed Jan 19, 2008 @5pm > "kk2ed" <[EMAIL PROTECTED]> wrote: > > Well it looks like the problem is with the 15,000uf caps. Two of > them appear to have leaked a brown substance. The power supply is a > TPN 1110A (or something close - it's still in my truck). > > Has anyone found a suitable replacement caps for these supplies, or > am I better of junking it and buying another unit? > > > Eric > KE2D > > > > > > > > > > > > > > --- In Repeater-Builder@yahoogroups.com, Mike Morris WA6ILQ > <wa6ilq@> wrote: > > > > At 09:39 PM 01/17/08, you wrote: > > >Let me clarify a little bit........ > > > > > >I am using the supply to power the Micor repeater as well as a > GM300 > > >link transceiver. A few weeks ago I started to notice a slight > hum > > >on the link radio's transmitted signal. Now, the hum is so bad, > and > > >voltage drop significant, that the GM300's transmit signal is > dirty > > >and sounds like a spurious emitter when transmitting. If I disable > > >the main repeater TX (Micor), so as to lessen the load and only > have > > >the GM300 transmitting, the hum goes away. Being the GM300 only > uses > > >the 13.8v output, I'm guessing the other outputs are ok. > > > > > >I forgot to mention - When I stopped at the site the other day, I > > >heard the transformer buzzing, which increased in loudness when > the > > >repeater was keyed (thus placing a heavier load on the > > >transformer). Possible transformer or resonant circuit capacitor > > >failure? > > > > > >I will be stopping at the site in the morning to investigate > further > > >and swap it out with a spare. I'll report back with my findings > > >later tomorrow. > > > > > >Thanks > > >Eric > > >KE2D > > > > > > > > > > > > > > > > > >--- In Repeater-Builder@yahoogroups.com, Eric Grabowski > > ><ejgrabowski@> wrote: > > > > > > > > While I don't have experience with that particular > > > > power supply, the situation you describe is > > > > symptomatic of filter capacitor failure. > > > > > > > > The capacitor's equivalent series resistance (ESR) > > > > becomes so high that it doesn't filter the ac ripple > > > > anymore. > > > > > > > > You should be able to verify this easily by using a > > > > scope to observe the ac ripple on the dc output under > > > > various load conditions. > > > > > > > > Eric KH6CQ > > > > > > > > --- kk2ed <kk2ed@> wrote: > > > > > > > > > Good Evening, > > > > > > > > > > I have a Micor 75 station power supply that is > > > > > acting up. When the > > > > > repeater is idle, the voltage output appears clean. > > > > > But as the load > > > > > is increased (ie: power output increased), the > > > > > voltage sags and I > > > > > get an annoying hum on the tx (indicative of AC > > > > > ripple on the dc > > > > > side?). It started out as a barely noticeable hum; > > > > > the past few > > > > > days it has gotten to the point where I just shut > > > > > down the > > > > > repeater's tx. > > > > > > > > > > I haven't had a chance to get to the site to swap it > > > > > out with a > > > > > spare. But I'm curious as to what kind of repair I'm > > > > > in for, and > > > > > others' experience with Micor supplies. > > > > > > > > > > What tends to be the failure and/or cause of the > > > > > above condition? > > > > > > > > > > Pass transistor failure? Filter caps? Ferro-resonant > > > > > circuit (cap)? > > > > > > > > > > Thanks for any input > > > > > Eric > > > > > KE2D > > > > I'll bet it's the resonant capacitor, but as long as you are > > in there you will want to look at every electrolytic. > > > > Mike WA6ILQ > > >
