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The purpose of silent frames is to pad a superframe if the transmission ends before the superframe ends. Or at the beginning of the transmission while the microphone is muted. I believe NXDN documents say that those frames are added whenever the input sound is less than -90db. I have however...

I monitor a system that has about 150 sites which none are simulcast. The manner in which I scan is with ID search, so looking for any talk group. The issue I am having is that at most instances the scanner is scanning between these 150 sites and rarely pauses on the active sites. So more time...

A site provides a list of all of its currently active TGs? A feature where the scanner can auto lock to the best received site would also help. No need to necessarily use, or worry about the adjacent site messages. Having to scan through more than 100 sites where maybe only 3 top are in range...

OP25 utilizes MBELib I believe, and SDRTrunk uses its own vocoder, JMBE. Both use concepts that are reverse engineered, or based on P25 Half Rate standard documents. Both are not perfect, and are not as good as the official AMBE 2+ vocoder, but get quite close, free, and run directly on your...

Is the DVstick 30/ AMBE 3000 compatible with IMBE P25 Phase 1 frames(with FEC)? When trying P25 phase 1 frames(with FEC), both interleaved, and deinterleaved, with various rates, and the RCW indicated through DVSI I am getting garbled audio. It is my understanding that DVSI sells their own USB...

Is it possible to have 1 talkgroup receive multiple (2) announcement talkgroups?

Observed it in use, and was wondering the same, however, unlike EP there is no key id, so I was not certain how it would know which key to try.

Is it possible on a BS DMR system to have some radios transmit in the clear, while others with a BP key, all while both will be able to hear one another?

hmm, I mean in theory why do we need to know the voice frequencies, the control channel will just tell us those also. More data to save.

Trunked radio system control channels are now all labeled the same. We can no longer see which is the primary control channel, or secondary control channels. Is this on purpose? Some systems have like 5 secondary control channels, it makes it trickier to find the primary. I would love to see the...

I actually went to the Vimeo video and it sounded better there. Watched the body cams where their radios are heard, and they sound pretty normal. Didn't notice any garble, or what not. I still think some of the other p2 systems I monitor do sound louder, and clearer.

Hmm that does not sound very good. Something about the voices is not very intelligible. It's not completely horrible, but my regularly monitored P25 Phase 2 systems, such as SVRCS, sound better.

Yeah it’s unfortunate. TDMA on P25 uses the AMBE vocoder which is about half the bitrate of what it was previously on FDMA (phase 1) which used the IMBE vocoder. I noticed also that the phase 1 voice could have much more errors and still sound okay. Versus on phase 2 with AMBE, where you get a...

Are you using a scanner, radio? Or an online feed? A thing worth trying is changing the deviation to 2.5 or FMN (narrow band). I have never monitored Santa Rosa Police. But it looks like on the database they are also on a digital P25 Trunked system. Could it be that they switched over and all...

Like in what way, garble because of say reception, or the actual sound quality of the vocoder?

Can multi_rx.py support multiple voice channels for one control channel at the same time. I added 2 more voice channels, and they are not allocated or used.

I have listened to both P25 Phase 2, and DMR, and for some reason DMR always sounds better. Louder, and crisper. But why is this, don't they both use the same vocoder, shouldn't it sound the same?

The P25 audio that is now used on top of encryption in SF sounds very different than what analog sounded like in their Motorola Type 2 system. But it doesn't have to do with encryption. It's using a digital vocoder, that is designed to process voice. It compresses the audio. The modern systems...

The software system key I assume is there to basically say, if you have it, the radio is a part of the system. If the radio is a part of the system, it's capable of taking up system resources, conflicting with radio ids, and transmitting on talkgroups. It is also at the same time able to be...

I have been trying to figure out, are the bursts in superframes actually labeled for the count of A through F? I do see that the first burst is identified with a sync word. But the rest are not. How can I identify the rest of the bursts in the superframe? Is there actual data being sent with...