Using a frequency counter with DRM

[Greggtheham]

I’m am new to DRM (actually, all amateur digital FM). While trying to get “my head around” a pre-programmed codeplug in my Anytone HT, I tested its xmit RF frequency output on an older handheld RadioShack LCD frequency counter ( good up to a gig) . I found out none of the digital (drm) frequencies (all on 70cm) could be read. Analogue FM was fine. I imagine it has something to do with the gate speed of the counter and how it works with Time Domain. So what special specs does an RF frequency counter need to read digital TDMA (and FDMA) for RF frequency ? Regardless of the TDMA, is the 12.5KHz bandwidth perhaps too narrow for this counter? I am sure having a hard time adjusting to the “FM” digital realm ...note; pushing the counters “ gate speed“ count button while xmitting does result in some non-70cm readings. Note sure if they are mathematically relevant or useful. Tnx es 73

 

[N4KVE]

Remember the DMR signal is pulsing on, & off every 30 ms. RF power readings will also be off, as well as current draw. Just do your tests in analog.

 

[Greggtheham]

Tnx for ur reply. Good point abt pulsating affecting power reading also.

I am only looking to find unknown frequency, so perhaps a frequency counter with fast enough gate speed will work, although my handheld Counter (RS 22-306) has gate speeds selection of 64 or 640 ms.

Seems like I am missing either a very simple solution, or a very expensive one (Referring to a radio service monitor /scope etc.) . Perhaps a cheap SDR RealTek software solution.
This is a case where frequency is not transmitted in Analogue, so no cheating by first getting frequency that way.
TNX ..Gregg

 

[slicerwizard]

Just get a cheap SDR. Done and done.

 

[KE5MC]

Slicerwizard makes a good point. Of course a SDR setup to find frequencies is another 'rabbit hole' you can go down and get lost in. Don't ask me how I know...

 

[Tinkerwave]

Slicerwizard makes a good point. Of course a SDR setup to find frequencies is another 'rabbit hole' you can go down and get lost in. Don't ask me how I know...

Can you recommend one that quickly scans for and alerts on P25 phase 2 slot 1/slot 2?

 

[jaspence]

Why not use a scanner or DMR radio? The CS580 from Connect Systems is a good small handheld that can read the time slot and CC and put them into memory. It is UHF only, but works well. The BTech 6x2 also has good scan capabilities and is dual band but is double the cost of the CS580.

 

[KE5MC]

Can you recommend one that quickly scans for and alerts on P25 phase 2 slot 1/slot 2?

Tinkerwave,
You should start a new thread with your question or search as it has been asked many time.

For questions like yours I always suggest the following link as a starting point. You will have much to read and it will lead deeper down the "rabbit hole".

https://www.rtl-sdr.com/

Good Luck!
Mike

 

[Tinkerwave]

Gotcha @KE5MC thanks. I've been down that rabbit hole for a few months now. I haven't found the remaining answers I'm looking for, and was hoping you had found the magic "carrot" (i.e. for the rabbit) lol. I'll keep digging

 

[KD8HMJ]

On the connect systems 580 fui they make a vhf version too if that helps. 73 john