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Pdc250 frequency counter on Uniden washington

Harley3315

Well-Known Member
Oct 22, 2015
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Would like to know where I can tap in to the radio and use the rca jack on the back of the radio and read am rx
I tried to tap the spot with 68pf cap that would be used on the galaxy type counter fc347 I think it was and the counter
reads 35.034 any idea what to do here?
 

seems like that counter doesn't have a built in offset.

if you open it up and that RCA jack is connected to the center conductor of those SO-239's then it's just reading the direct frequency put into it.

you are reading the 35mhz signal from the PLL right now.

i dont think there's a way to use that counter to monitor 27mhz receive but i could be wrong.
LC
 
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seems like that counter doesn't have a built in offset.

if you open it up and that RCA jack is connected to the center conductor of those SO-239's then it's just reading the direct frequency put into it.

you are reading the 35mhz signal from the PLL right now.

i dont think there's a way to use that counter to monitor 27mhz receive but i could be wrong.
LC
Well what way are you thinking to do it?
 
that counter is meant to be put in line with the antenna jack of the radio and will only read on TX if it's configured on the inside like i think it is.
i say i could be wrong because i don't know what the inside of the counter looks like.
LC
 
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There was a different model, the PDC256 that was built with an internal offset feature. It had no antenna-coax sockets since it was built to tap directly into the radio's VCO the way you hooked up this one. There were four so-called "DIP" switches that served to select the frequency offset. This is what allowed it to display the channel frequency while receiving.

The "250" model is only set up to read the radio's AM carrier frequency while you are keyed, and the mike gain is turned down.

This Ebay widget will pretty much do the same thing. The offset frequency isn't set with hard switches, but with a setup sequence controlled by two pushbuttons on the board.

https://www.ebay.com/itm/3215178846...d=link&campid=5336136228&toolid=20001&mkevt=1

Just three drawbacks:

No enclosure.

And it needs a lower power-supply voltage than the 13.8 Volts that runs the radio. We use a TO-220 "7808" 3-terminal regulator for this. And this regulator serves to isolate annoying digital noises from the radio's receive audio.

It has only one offset number. A sideband radio will need three of them, one for AM, and one each for upper and lower sideband. You can set it up to read accurately for only one mode. It will be wrong on the other two modes.



73
 
There was a different model, the PDC256 that was built with an internal offset feature. It had no antenna-coax sockets since it was built to tap directly into the radio's VCO the way you hooked up this one. There were four so-called "DIP" switches that served to select the frequency offset. This is what allowed it to display the channel frequency while receiving.

The "250" model is only set up to read the radio's AM carrier frequency while you are keyed, and the mike gain is turned down.

This Ebay widget will pretty much do the same thing. The offset frequency isn't set with hard switches, but with a setup sequence controlled by two pushbuttons on the board.

https://www.ebay.com/itm/3215178846...d=link&campid=5336136228&toolid=20001&mkevt=1

Just three drawbacks:

No enclosure.

And it needs a lower power-supply voltage than the 13.8 Volts that runs the radio. We use a TO-220 "7808" 3-terminal regulator for this. And this regulator serves to isolate annoying digital noises from the radio's receive audio.

It has only one offset number. A sideband radio will need three of them, one for AM, and one each for upper and lower sideband. You can set it up to read accurately for only one mode. It will be wrong on the other two modes.



73
Seemed like the ebay one I got a few years back was set up for 2 offsets and could do 2 modes correctly so am and one of the 2 side bands some had solder terminals in the middle of the board that were marked for side band but I never tried to hook it up like say a 347 Galaxy counter to see what would happen.
 
There was a different model, the PDC256 that was built with an internal offset feature. It had no antenna-coax sockets since it was built to tap directly into the radio's VCO the way you hooked up this one. There were four so-called "DIP" switches that served to select the frequency offset. This is what allowed it to display the channel frequency while receiving.

The "250" model is only set up to read the radio's AM carrier frequency while you are keyed, and the mike gain is turned down.

This Ebay widget will pretty much do the same thing. The offset frequency isn't set with hard switches, but with a setup sequence controlled by two pushbuttons on the board.

https://www.ebay.com/itm/3215178846...d=link&campid=5336136228&toolid=20001&mkevt=1

Just three drawbacks:

No enclosure.

And it needs a lower power-supply voltage than the 13.8 Volts that runs the radio. We use a TO-220 "7808" 3-terminal regulator for this. And this regulator serves to isolate annoying digital noises from the radio's receive audio.

It has only one offset number. A sideband radio will need three of them, one for AM, and one each for upper and lower sideband. You can set it up to read accurately for only one mode. It will be wrong on the other two modes.



73
Looking for a little help setting one of these up on my uniden washington, only realy need it for usb freebanding
 
There was a different model, the PDC256 that was built with an internal offset feature. It had no antenna-coax sockets since it was built to tap directly into the radio's VCO the way you hooked up this one. There were four so-called "DIP" switches that served to select the frequency offset. This is what allowed it to display the channel frequency while receiving.

The "250" model is only set up to read the radio's AM carrier frequency while you are keyed, and the mike gain is turned down.

This Ebay widget will pretty much do the same thing. The offset frequency isn't set with hard switches, but with a setup sequence controlled by two pushbuttons on the board.

https://www.ebay.com/itm/3215178846...d=link&campid=5336136228&toolid=20001&mkevt=1

Just three drawbacks:

No enclosure.

And it needs a lower power-supply voltage than the 13.8 Volts that runs the radio. We use a TO-220 "7808" 3-terminal regulator for this. And this regulator serves to isolate annoying digital noises from the radio's receive audio.

It has only one offset number. A sideband radio will need three of them, one for AM, and one each for upper and lower sideband. You can set it up to read accurately for only one mode. It will be wrong on the other two modes.



73
I will be getting several more of these, thanks nomadradio for the help. I do think I need to ad a capacitor inline with the power supply to the meter because if I turn on the radio with the counter connected the counter overloads I think.
 

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