MCS2000 Model III head - no volume control

mam1081 · Post by **mam1081** » Wed Feb 15, 2006 9:50 pm

I have a UHF high-power remote mount MCS2000 that will not allow adjustment of the audio volume. It is set at a volume that is understandable inside, but probably wouldn't be acceptable for a mobile environment. I tried a second head on there (a spare that we weren't sure was all "good"), and had the same problem. I tried another head (one that I knew worked on another similar radio), and it worked. Is there a way I could get a new audio volume pot for that? I am reasonably sure at my desolder/soldering skills and think I could do the swap. I could not find the part number for it and do not know of any alternate parts I could use. Anyone with some genuine part numbers (and costs) for that...or suggestions on things to try?

As a last resort, anyone have a spare MCS2000 III head that works lying around??

jackhackett · Post by **jackhackett** » Thu Feb 16, 2006 6:02 am

Are all of the heads you tried exactly the same kind? Some of them aren't rear heads are they (I believe they will have it marked on the housing)?

I'd verify that it's the pot before trying to find a replacement, you should be able to check it with an ohmmeter.

Post by **alex** » Thu Feb 16, 2006 6:46 am

That also may be a rear control head.

Rear control heads do not have volume controls. Last I checked, when you order a MCS2000 in a dual head configuration, the seccond speaker for the rear control head has it's own built in volume control.

-Alex

mam1081 · Post by **mam1081** » Thu Feb 16, 2006 6:56 am

Which pins should read what? I verified that the "push button" function (to turn the radio on and off) works. I could not get much resistive change one any combination of pins I tried while turning the knob (that's why I thought it needed to be replaced).

I don't think it's a rear head, but I'll check that later. Definately something I didn't think of.

jackhackett · Post by **jackhackett** » Thu Feb 16, 2006 2:02 pm

The center pin is the wiper, from that to either end you should get a varying resistance, close to zero ohms when the pot is turned all the way to one side, and close to the value of the pot when turned the other way, I forget value they use in the MCS, probably either 5000 ohms or 20,000. As the resistance from one side to the center goes up, the other side should go down.

I'll try to find the part number tomorrow.

mam1081 · Post by **mam1081** » Thu Feb 16, 2006 8:20 pm

Well, it does say "REAR CONTROL HEAD" on the back of the head. My friend's that had the volume that worked on here did too though.

I just tried swapping the pot with the other "questionable" face, and have the same problem. Is there something else it could be? Are rear heads not supposed to be able to change volume?

Post by **wavetar** » Sat Feb 18, 2006 5:56 am

mam1081 wrote:Well, it does say "REAR CONTROL HEAD" on the back of the head. My friend's that had the volume that worked on here did too though.

I just tried swapping the pot with the other "questionable" face, and have the same problem. Is there something else it could be? Are rear heads not supposed to be able to change volume?

Rear heads cannot change the volume...the MCS2000 has an amplified external speaker with it's own volume control for RX audio. I guess it was the only way to get independant volume control of both front & rear speakers in a dual head set-up. I have no idea why your friend's control head worked, unless it had been re-cased at some point & someone just threw a "rear head" back piece onto it.

Todd