Help with an MSR2000 VHF power amp module?

The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

Moderator: Queue Moderator

Post Reply
User avatar
Elroy Jetson
Posts: 1158
Joined: Mon Sep 03, 2001 4:00 pm

Help with an MSR2000 VHF power amp module?

Post by Elroy Jetson »

I have a 110 watt, intermittent duty VHF power amp module from an MSR2000 repeater that I'd like to get some use out of

Part number is TLD2532A.

There are positive and ground connections, power input and output connectors, and three more pins for control signals
and voltages that I know nothing about.

Can someone who has the manual take a look and tell me what I need to connect to this power amp to get it running?

Elroy
User avatar
Tron
Posts: 260
Joined: Fri Sep 14, 2001 4:00 pm
What radios do you own?: Too many to list

Re: Help with an MSR2000 VHF power amp module?

Post by Tron »

Pin 1 is control voltage that sends A+ back to power the final and driver on the exciter board, ~6v

Pin 2 is ground

Pin 3 sends switched 9.3v to the power control board.

Tron
"Where the Old Soo crosses the New Soo, Duplainville, Wisconsin"
User avatar
Elroy Jetson
Posts: 1158
Joined: Mon Sep 03, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Elroy Jetson »

Thanks. And what's the primary supply voltage to the PA? Somehow I'd be a bit surprised if it was 12 volts but...maybe.

Elroy
Al
Posts: 1045
Joined: Tue Sep 04, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Al »

Yup, it's 13.5VDC nominal.
User avatar
Elroy Jetson
Posts: 1158
Joined: Mon Sep 03, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Elroy Jetson »

So far so good...now for a critical question:

Pins 1, 2, and 3 aren't labelled and I don't have the manual. Can you please guide me as to which pin is which?

And, what's the nominal input power to drive it to its full nominal output power?


Elroy
Al
Posts: 1045
Joined: Tue Sep 04, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Al »

According to my TLD2532A manual, maximum RF power input is 1.5 watts.
The connector you're referring to is on the power control board, J902. If you look at the board from the component side with the RCA type jack and directional coupler on your left, the pins on J902 are 1, 2, and 3 from left to right. As someone said earlier, pin 1 is switched 9.3V source from the exciter, 2 is ground, and 3 is the conditioned power control voltage from the directional coupler.
User avatar
Elroy Jetson
Posts: 1158
Joined: Mon Sep 03, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Elroy Jetson »

I'll need to figure out how to control power via pin 3 as I'm not planning to use a directional coupler.

I figure I can do some experiments with a variable power supply and see how voltage on that pin correlates to output power.

Elroy
Al
Posts: 1045
Joined: Tue Sep 04, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Al »

Pin 3 is an output *originating at* the directional coupler on the power control board.....it merely outputs a variable voltage to the exciter section to maintain a relatively constant RF output from the PA board section of the amp. If you're going to drive this PA without a power levelling loop, you don't need to worry about pin 3. Power output should be proportional to the drive level(approximately).
I just wanted to be sure you understood that pin 3 was an output and not an input.
User avatar
Elroy Jetson
Posts: 1158
Joined: Mon Sep 03, 2001 4:00 pm

Re: Help with an MSR2000 VHF power amp module?

Post by Elroy Jetson »

Now I certainly do. Thanks.

Elroy
nuzzoj
New User
Posts: 1
Joined: Thu Nov 29, 2012 6:12 pm

Re: Help with an MSR2000 VHF power amp module?

Post by nuzzoj »

i have a msr2000 uhf power do the same connections apply to me? if i wanted to it as a standalone PA do i still need those connection 1,2,3 or can i just drive it with a radio and power the power amp with the 13 volts?
Post Reply

Return to “General Motorola Solutions & Legacy Radio Discussion”