Is the speaker connected to the MASTR II? If you disconnected the speaker, the AF amp can oscillate, which could make this noise...
Jeff At 05:33 PM 2/20/2007, you wrote: >There could be a number of reasons. You are going to have to be a >little more specific as Poping a really vague term. If possible try >recording it and post it as a .WAV or .MP3. > >This could be anything from a loose wire to desence caused by the >oscillators in the controller. > >My research says: > >"I've seen that crap before...." > >+10V mic bias coming from the exciter down the audio path into the >controller and not playing nice with the half VCC biased amplifiers. >This can also be a problem in the long run as a +10 volt biased line >on the output will charge the AC coupling capcitors backwards which >are between 6 and 7 volts on their positive side and cause them to >fail. > >I've even had the capacitors stop passing audio, wait for me to get to >the site, open the equipement, and blow up, right in my face... Mike >Rowe would be proud... Anyway, electrolytic or any other polarized >capacitors do not belong in an AC path where DC bias can occur. > >If this is your problem there are a number of solutions. One would be >to put a non-polar capacitor in series with your TX audio path or >replace the polarized capcitors in the controller with non-polar >ceramics. I personally would recommend eliminating the bias supply >resistor from the MASTR-II exciter, I think it was a 620 or 680 ohm >resistor. > >But this may not be your problem... > >On 2/20/07, Ken Sanders <<mailto:ae6la%40aol.com>[EMAIL PROTECTED]> wrote: > > Hi All, > > > > I'm pretty inexperienced but find myself in charge of a nice repeater > > operation, 145.170 - N6FRG in Angels Camp, CA. This is a GE Mastr II > > mobil unit that has been in service for many, many years. We just > > replaced the 1980s era SC-1 controller with an Arcom RC210 and have a > > poping noise when repeating but not during the voice announcements. Any > > suggestions for a cure will be appreciated. > > > > 73, Ken Sanders - AE6LA > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > >
