newbie question

[huskyfan68]

Hi- I am not sure where to post this- I am not well versed with radios- hope someone can help.
I "inherited" a few Motorola Radius P1225 walkies and a few Motorola CP150's. (they all charge and turn on)
questions:
1. How do I tell what frequency the radios use?
2. The 1225's talk to each other (another 1225)- how do I get it to talk to the CP150?

thanks!

 

[bnt133]

You are going to have to bring them to a radio tech and have them read and reprogram the radios.

 

[copperhd]

What frequency are they on?

It can be simple to find the frequency in most cases. First look them over front & back or even inside for a tag that will ID the freq, most radios will be marked somewhere. If not, the find somebody that has (and knows how to use) a freq counter. A freq counter is a relative cheap, small piece of equipment that a lot of radio hobby fans own ( I have one purchased in my old cb radio days for $99 from radio shack).They are held near your transmitter antenna & when it is keyed up (without modulation) the counter will read/display received frequency. Then you can determine if it is legal for you to operate there and if so at what power output level.r

 

[N4KVE]

These are good, & even display the PL tone About $50.
Jetstream JTFR1B Frequency Counter

 

[huskyfan68]

thanks- I will look into that- on the other question- is it possible to make the 2 models talk to each other?

 

[WA0CBW]

If they are the same band (UHF/VHF), have the same frequencies, and the same PL/DPL they should talk to each other.

 

[huskyfan68]

OK I checked- (manual on line)- the P1225 are UHF on 450-470MHZ- the Mag Ones (BPR40) are UHF also d on tht same frequency... they do not talk to each other- Help! I wish I understood how this works better.....

 

[jhal94]

OK I checked- (manual on line)- the P1225 are UHF on 450-470MHZ- the Mag Ones (BPR40) are UHF also d on tht same frequency... they do not talk to each other- Help! I wish I understood how this works better.....

Radio channels must be programmed to match the other radio's channels. A channel is just a user defined section, it's not a universally determined frequency. 450-470 is just a range of available frequencies for the radio to use on it's programmable channels, such as: 456.8, or 462.55, or 465.8375.

A radio may use both an Talk (TX) and Receive (RX) frequency. It has the option for both input and output so that it may do things such as duplex (talk and receive voice at the same time, most radios don't have this however) or accessing a repeater (a radio that re-transmits the input (TX) frequencies signal on another (the RX) frequency, usually at a higher power). A simplex channel uses the same frequency for both TX and RX for simple radio to radio stuff without a repeater present (usually all that is necessary)

Now, there are also things called squelch codes. They can come in the CTCSS(PL) or DPL variety. These allow for the channels to be coded so that you can contain the traffic for one set of users from the other if they both use the same channel. This does not mean they wont interfere with each other, but they wont hear each other either. Honestly I don't know of anyone who uses this for that purpose (there are other uses) but that's what it's for.

So for a radio (basic radios, no trunking or MDC/DTMF/whatever) to communicate with another radio it needs to have matching Frequencies and matching Squelch tones (no squelch tones at all works too). So a basic simplex radio channel would be like:

Tx Frequency: 462.5625
Rx Frequency: 462.5625
Tx Squelch: 67.0 Htz
Rx Squelch: 67.0 Htz

Both radios would have to have this channel programming to work together. The only way to determine the programming on your radios is to either: Scan them with a frequency counter or a regular scanner (preferably one that can detect squelch tones), or, have them read by someone with a computer and interface to look at the programming.