What type PA are you referring to ? UHF or VHF ? Model No. ? The power control Bd on the UHF has 2 pots for setting the output level. Make sure they are clean (contact cleaner and rotating back and forth while spraying) The left one, as you face the rptr. sets the upper limit of the power level (by regulation the max, current to the PA), the second one allows you to vary the out put power with in the preset limits. This is apparently a Motorola safety feature. If your having the same problem with 2 Bds. then most likely it is not bad boards.
Next item would be to open up the PA and reflow/resolder the solder at all the power transisters legs (these have a tendency to develope cold joints or de-solder themselves over time from heat and age. also flow fresh solder along all the power traces between the transisters to insure they are not cracked, corroded or causing a high resistance. Look for any other damage to component and touch up all the connections you can with the soldering iron. I belive the VHF Micor is basically the same except on the PA the traces between the pwr transisters are not as exposed and as long as on the UHF PA. I did the above to my UHF Micor that had dropped down to about 60w max. and the Max. output jumped to about 112W, but I turned it back to 75W. If that doesn't help then. Maybe someone else out there has a suggestion or two. If I made any incorrect statements i'm sure someone will correct them for you also. -- Doug N3DAB/WPRX486/WPJL709 ---- georgiaskywarn <[EMAIL PROTECTED]> wrote: ============= Ok. Let's look at this then. I have no power control from the Power Control Board. Can't turn it up or down. Tried 2 different boards as well. 1) Ideas? 2) Don't have the schematic in front of me....but can't find the caps on the schematics I have...listed from the below web site. Thanks, Robert --- In Repeater-Builder@yahoogroups.com, "Gary Glaenzer" <[EMAIL PROTECTED]> wrote: > > "there is no 100 watt Micor amp" > > without qualifiers, that is a pretty broad statement............ > > Gary > > > ----- Original Message ----- > From: Captainlance > To: Repeater-Builder@yahoogroups.com > Sent: Thursday, October 30, 2008 10:11 AM > Subject: Re: [Repeater-Builder] Micor PA schematic / Power Control Board > > > > The PA is only factory rated at 78 watts...there is no 100 watt Micor amp. Some however, will do 100... > Lance N2HBA > ----- Original Message ----- > From: georgiaskywarn > To: Repeater-Builder@yahoogroups.com > Sent: Thursday, October 30, 2008 5:44 AM > Subject: [Repeater-Builder] Micor PA schematic / Power Control Board > > > Anybody have a schematic for the Micor 100watt PA? > > Also can only get about 78 watts out of this thing. Have changed out > the power control board...either board the power doesn't go up or > down. Ideas? Haven't tried this yet; > http://www.hamrepeater.org/micr_uhf.htm (bottom of the page to defeat > this portion) > but am going to try it tonight. > > Thanks, > Robert > KD4YDC > > > > > > -------------------------------------------------------------------- -------- > > > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.175 / Virus Database: 270.8.5/1755 - Release Date: 10/29/2008 5:27 PM >
