hi.
i have 2 MOTOROLA TA280slk’s. both are good and work with each other. the problem is maching those radios with other radios. i set the channel of TA280 for example on “1” (FRS,GMRS 462.5625) , and set the frequency on other radio on “462.5625” and disable the “ctcss codes”. but they dont work with each other. is it posible that the frequencies of TA280slk be out of FRS and GMRS? i even test PMR446 channels on both radios. bot didnt work. how can i find my TA280slk’s frequensies? (in user manual you can find 14 ch of FRS,GMRS frequency table)
thanks.
Greetings!
The Motorola TA280SLK manual can be found Here
According to it, your frequency table is as follows (page 30):
Channel MHz
1 462.5625
2 462.5875
3 462.6125
4 462.6375
5 462.6625
6 462.6875
7 462.7125
8 467.5625
9 467.5875
10 467.6125
11 467.6375
12 467.6625
13 467.6875
14 467.7125
Note that as a 14-channel FRS radio, you only have FRS frequencies- not GMRS. Note that some of the FRS frequencies are shared between FRS and GMRS, you can get those but not the GMRS-only ones.
You may also find this helpful- it’s a complete list of all the FRS/GMRS frequencies, not including repeater inputs (which you don’t need) (22 total)
To disable the CTCSS tone, set it to code 0…
Now if your other radio can’t receive, first make sure that it isn’t set for CTCSS tone. If the motorola is set to code 0 (CTCSS disabled) then the Mot should pick up a transmission from the other radio, assuming it’s on the right channel. If this doesn’t work, your other radio is transmitting on the wrong frequency and/or isn’t programmed right. You can also try pushing the ‘monitor’ button on the talkabout, which opens the squelch gate (more on this in a sec) and plays whatever is on the frequency.
So with your radio set to ‘code 0’, you’re using normal signal-level type squelch, and with ‘monitor’ on the squelch gate is forced open. If the other radio is on the right channel, you should hear it.
What’s the make/model of the other radio? With that info I or someone else can look it up and advise if it’s even compatible… It’s more likely (in my opinion at least) that there’s something going on with the other radio.
Also, you should avoid using any of the PMR446 channels- 446MHz in the USA falls inside the Amateur (HAM) radio allocation and you must have a ham license/callsign to transmit. Unlike GMRS licensing, the FCC DOES actively enforce ham licensing.
A word on CTCSS tones (aka privacy codes, interference eliminator codes, etc)-
Whenever any radio is turned on, it’s listening to whatever frequency its set to. Most of the time, there will be no transmissions so it would just hear static. If you’re like most people, you won’t want to listen to static all the time. So a radio has a thing called a squelch gate- it only plays the received audio through to the speaker if it detects above a certain signal level. Once a signal of sufficient strength is detected, the squelch opens and audio is played. When the other person stops transmitting, the signal level of course drops and the squelch gate closes again. Many radios let you adjust the required signal level at which the squelch opens- this is the squelch adjustment.
However squelch has one big flaw- it only works on signal level. So strong interference can open the squelch and make the radio play bursts of static, and also only one set of people can use a channel at one time, because both groups would hear each others transmissions.
Enter CTCSS. CTCSS injects a low-frequency audio tone (think of the hum you get from a badly wired guitar amp) into the transmitted audio. The other radio looks for this particular frequency of audio in the incoming signal, and only opens the squelch if that particular tone is coming in strongly. Because most 2-way radios only play to the user audio frequencies above 300Hz, the tone (always below 300Hz) is filtered out and the user doesn’t hear it. You will find a list of the CTCSS tones your radio uses on page 31 of the manual I linked above.
The advantage of CTCSS is it’s more reliable than standard squelch, and it lets two or more groups use the same channel without hearing each others radio calls.
The disadvantage is that because you have two users on the same channel, two users (from different groups) could inadvertently transmit at the same time, and neither transmission would get through.
Hope that helps!
wow! what a perfect answer.
First of all thaks for your useful informations.
I do all, step by step, but i can’t do anything. i try to match my TA280slk’s with Puxing radios. as you know, you can input the frequencies manualy on Puxing radios. i input all 14 channels on puxing’s but can’t match them together. this proses work’s with Motorola 5720 (pairing Puxing with Motorola 5720) wich i have a pair of them too. by the way, i bought TA280slk’s, second hand. is it posible that they program TA280slk’s and change the frequencies? (if TA280slk is programable).
if yes or even no, how can i find the ‘new’ frequencies of TA280slk? or is there any other frequency table for TA280slk? (I don’t live in US)
thanks again.
Ah, you don’t live in USA. That’s the key element.
If I’ve understood correctly:
Puxing + Mot 5720 = works
Puxing + TA280SLK = doesn’t work
Mot 5720 + TA280SLK = doesn’t work
right?
If that’s the case, it sounds like you might have a foreign model of the TA280SLK, with frequencies designed for that country. You mentioned PMR446, so here is the PMR446 frequency table
1 446.00625
2 446.01875
3 446.03125
4 446.04375
5 446.05625
6 446.06875
7 446.08125
8 446.09375
Try those channels on the Puxing radio.
If none of this works, find someone with a good scanner (or if the Puxing radio has a scan function that searches frequencies and not channels, use it). Remove the scanner’s antenna (or turn on its ATT (attenuator) function, or both) to reduce the signal level- you only want to pick up your TA280SLK (which is right next to the scanner) and not other things far away.
Now transmit on the TA280SLK, set the scanner for around 400MHz and let it scan up to 500MHz while the TA280SLK is transmitting. You should find the frequency somewhere in there. If not start at around 100MHz and scan to 200MHz, it might be in there too.
If the TA280SLK has an FCC ID number on it (probably on the back, or under the battery), use this website to look up the FCC ID. It should show you the frequencies.
Good luck!