Motorola Radius P50

[dhiatt10]

Hello,
If anyone knows the answer to this question please let me know, it would be a huge help

I was digging through my drawers and found a pair of Radius P50 radios a friend of mine gave to me a while ago. they both power up, and hold a good charge.

The problem is that they dont talk to each other. i got my scanner out and they both transmit on freq = 44.6200. both transmit just fine. i looked at the jumper settings on the back of the radios and there both set alike.

Any suggestions??

thanks alot
Don

 

[INDY72]

Can you check to see what CTCSS/CDCSS if any they are set on....

 

[scanfan03]

Do you have a 92 or 96 or any new Uniden? You would be able to check the PL of the transmit on each radio with those scanners.

 

[dhiatt10]

I dont know what " CTCSS/CDCSS " is nor do i know if the radios have it.

As for the scanner its the Uniden BC250D with the Digital card

Hope this helps
Don

 

[scanfan03]

ok, ask someone how to search for PL's and DPL's on that scanner, I don't know how, I only know how on the 92 and 96. I know the 250D can do it just don't know how. Look in your manual.

 

[Voyager]

I dont know what " CTCSS/CDCSS " is nor do i know if the radios have it.

As for the scanner its the Uniden BC250D with the Digital card

Hope this helps
Don

You can look under the brown cover behind the battery to see if there is a board installed. If not, they cannot have CTCSS/CDCSS. If there is a board, they may be on different tones OR they may have two-tone decode programmed in them. In either case, you should be able to to disable any decoding by opening up the squelch with the squelch knob. Turn it so it is not in the detent position.

Hmmm... I just re-read your original email. IF there are jumpers (I'm assuming that's what you are calling the dip switches) in the back, they do have either CTCSS or CDCSS (but two-tone decode is not possible), but still, try opening up the squelch as described above. If it still doesn't work, either one has a bad TX crystal or the other has a bad RX crystal is most likely the problem.

Joe M.

 

[dhiatt10]

Yea i checked the Dip Switeches and there both set the same as the other.
Ive also tried with the squeltch all the way open on both. As for the RX crystal.... the funny thing is i can pick up some conversation on both radios, but i tried to talk to them but i guess they are to far away for them to her me.

 

[Voyager]

Yea i checked the Dip Switeches and there both set the same as the other.
Ive also tried with the squeltch all the way open on both. As for the RX crystal.... the funny thing is i can pick up some conversation on both radios, but i tried to talk to them but i guess they are to far away for them to her me.

OK. If you're picking up conversations on both radios, I would suspect a bad (or missing) TX crystal on the one you can't talk on.

Joe M.

 

[dhiatt10]

they both transmit just fine, the scanner picked both radios when i trasmit from either one.

 

[AZScanner]

they both transmit just fine, the scanner picked both radios when i trasmit from either one.

Here's how you can see if they are using different PL's:

Program the TX freq in your BC250D

Go into the menu and change the Squelch Mode to Tone Search.

Exit the menu and initiate hold on the channel that has the TX freq. Now, start TXing on one of the radios and keep going until your BC250 starts flashing the tone on it's screen. Then check the other radio in the same manner. My guess is that the PL's are different and that's why they won't talk to each other.

-AZ

 

[Voyager]

they both transmit just fine, the scanner picked both radios when i trasmit from either one.

Here's how you can see if they are using different PL's:

Program the TX freq in your BC250D

Go into the menu and change the Squelch Mode to Tone Search.

Exit the menu and initiate hold on the channel that has the TX freq. Now, start TXing on one of the radios and keep going until your BC250 starts flashing the tone on it's screen. Then check the other radio in the same manner. My guess is that the PL's are different and that's why they won't talk to each other.

-AZ

It's not different PLs if the squelch is open on both units.

So, just to retrace the steps so far, you can hear both units on a scanner, and with open squelch you can't hear them on each other. My next bet is that they are on a repeater pair and won't talk directly to each other. This is very uncommon on Low Band (44 MHz), but not unheard of. Or, they are on a half duplex pair (they TX on one frequency and RX on another). Again, they would not talk to each other in that configuration.

Joe M.

 

[bg6qam]

The P50 is not a synthesized radio and therefore is not programmable. Use these charts to set the PL or DPL frequency.

The P50+ programmer should be the same pinout as the P100. Just put the data line to the contact on the PL/DTMF board and the ground to the -battery clip. This is only a programming interface to the accessory board and programs PL,DPL,DTMF info. No channels can be changed as it is not synthesized either.

Another note on the P50+ is that "full-line" Motorola dealers sold a version known as the HT-10 which uses the same programming adapter but uses its own unique software and has a tan case.

我找到了以上这些资料，不知是什么意思~~~~~~~~
来源： http://216.232.87.119/p50plus.html



The formulae for calculating the crystal frequencies are as follows:

UHF
Receive
fc = 8fo - 21.4MHz (403-430MHz)
fc = 8fo + 21.4MHz (440-512MHz)
where fc = desired carrier frequency
fo = first oscillator (crystal) frequency
Transmit
fo = fc / 27
where fo = crystal frequency
fc = desired carrier frequency

VHF
Receive
fc = 3fo + 17.9MHz (136-174MHz)
where fc = desired carrier frequency
fo = first oscillator frequency
Transmit
fo = fc / 9
where fc = desired carrier frequency
fo = crystal frequency