Mitrek Base volume control question.

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Jay G.
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Posts: 378
Joined: Fri Sep 21, 2001 4:00 pm

Mitrek Base volume control question.

Post by Jay G. »

Hello all.

I still have in service a Mitrek low band base station radio. Works great! Inside the radio, just behind the externally viewable volume control is a master volume control pot. The motorola part # is 18D82515B27 for this pot. OBVIOUSLY it's not made anymore, or at least not listed on MOL. Can anyone decypher what this is in terms of ohms, wattage etc... so I can try to find a replacement? I dont want to just get any old thing and break this precious antique!

thanks to all!

please email directly if you can [email protected]
Jay Goldmark, EMT
Ex-Captain, Woodmere Vol. Fire Dept.
Fire District Communications Supv.
KC2ZHI Amateur Radio Operator
Licensed Master Electrician
Owner, Top Class Electric, LLC.
Woodmere, Long Island, NY


"Enjoy Life, it's not a dress rehearsal !!!"

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Lake Effect
Posts: 311
Joined: Tue Dec 06, 2005 9:47 am

Re: Mitrek Base volume control question.

Post by Lake Effect »

My book shows it as 25 k, +/-30%, 0.16 watt.

L.E.
Jay G.
Batboard $upporter
Posts: 378
Joined: Fri Sep 21, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Jay G. »

thanks! Now, the real question, anyone have a good source for these??

Prefer online sources.

thanks!
Jay Goldmark, EMT
Ex-Captain, Woodmere Vol. Fire Dept.
Fire District Communications Supv.
KC2ZHI Amateur Radio Operator
Licensed Master Electrician
Owner, Top Class Electric, LLC.
Woodmere, Long Island, NY


"Enjoy Life, it's not a dress rehearsal !!!"

************************************************************
Jay G.
Batboard $upporter
Posts: 378
Joined: Fri Sep 21, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Jay G. »

Thanks for the info.

Now i'm starting to wonder if it's only that one pot thats bad. Here's whats happening:

Volume on the radio itself is fine and stable.

External audio (hooked to PA system) is in and out. When I adjust the pot, it comes back. This time it lasted about 24 hrs. Is there something else I can check? I dont think it's the PA amp because there are other radios being fed in which are fine.

thanks for the help!

Jay G.
[email protected]
Jay Goldmark, EMT
Ex-Captain, Woodmere Vol. Fire Dept.
Fire District Communications Supv.
KC2ZHI Amateur Radio Operator
Licensed Master Electrician
Owner, Top Class Electric, LLC.
Woodmere, Long Island, NY


"Enjoy Life, it's not a dress rehearsal !!!"

************************************************************
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Will »

Where are you picking up the audio for the PA system?

The internal volume control is before the audio amp and audio gate, audio output stage. The front pannel Vol control is a speaker pad atenuator and only controls the local speaker.
Jay G.
Batboard $upporter
Posts: 378
Joined: Fri Sep 21, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Jay G. »

On the back of the base there are two rows of terminals. Bottom row, 3rd from left is marked in pen EXT SPKR - thats where one wire is, and then the ground is hooked up to a terminal marked GND on the top row.
Jay Goldmark, EMT
Ex-Captain, Woodmere Vol. Fire Dept.
Fire District Communications Supv.
KC2ZHI Amateur Radio Operator
Licensed Master Electrician
Owner, Top Class Electric, LLC.
Woodmere, Long Island, NY


"Enjoy Life, it's not a dress rehearsal !!!"

************************************************************
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Will »

TB2-3 is the 3.2 ohm external speaker terminal. If the volume level is going up and down the internal speaker should also be affected.

Fed from the audio output stage in the radio chassis.
Jay G.
Batboard $upporter
Posts: 378
Joined: Fri Sep 21, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Jay G. »

Will wrote:TB2-3 is the 3.2 ohm external speaker terminal. If the volume level is going up and down the internal speaker should also be affected.

Fed from the audio output stage in the radio chassis.
So since the internal speaker remains stable, are you telling me I should check it all AFTER that point?? Maybe the input on the PA amp??

thanks
Jay Goldmark, EMT
Ex-Captain, Woodmere Vol. Fire Dept.
Fire District Communications Supv.
KC2ZHI Amateur Radio Operator
Licensed Master Electrician
Owner, Top Class Electric, LLC.
Woodmere, Long Island, NY


"Enjoy Life, it's not a dress rehearsal !!!"

************************************************************
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: Mitrek Base volume control question.

Post by Will »

Jay G. wrote: So since the internal speaker remains stable, are you telling me I should check it all AFTER that point?? Maybe the input on the PA amp??
thanks
Yes, the speaker level should be going to the AUX input on the PA amplifier. The AUX input is usally for .1 to 1.0 volts audio.

If the level set in the Consolete is too high it could overdrive the input on the PA amplifier.
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