DMR Single Frequency Repeater on the Hytera PD985

Рет қаралды 6,801

Күн бұрын

So I bought a Hytera PD985 to test out the single frequency repeater. Very exciting. It works a lot better than the Radioddity GD-88 / Kydera DR-880UV Plus.
Kydera single frequency repeater video: • Radioddity GD-88 Singl...
0:00 Intro
0:16 Explanation of SFR
1:31 Backstory
2:20 How it works
4:42 Timeslot analysis of simplex transmission
5:35 Timeslot analysis of SFR
6:21 Guard time
7:08 Timeslot analysis of SFR and how it sounds
8:36 Issues
9:34 Demo

Пікірлер: 44

@bradkaral1188 Күн бұрын

Very well-explained. Just enough detail to be understandable.

@LavalampDM Күн бұрын

Thanks for this video Ben, I just played with some similar functionality on my Btech DMR 6x2 Pro. It's good to understand how this works.

@RingwayManchester Жыл бұрын

Cool stuff Ben and well explained

@radiosification Жыл бұрын

Thanks Lewis!

@Rypcipypci 5 ай бұрын

Very well explained, great video!! :)

@radiosification 2 ай бұрын

Thanks! It's very cool tech. I wanted to make another video showing it in action but it was hard to arrange for others to do a test with me from different locations

@tech-rich Жыл бұрын

Great video, a very interesting topic.

@radiosification Жыл бұрын

Thanks Rich! (I'm assuming that's your name based on your channel name)

@tech-rich Жыл бұрын

@@radiosification Correct!

@RabMac108AT10six Жыл бұрын

Hi @Radiosification, I've watched your videos for some time now and always enjoy them. Could you recommend a vhf UHF dual band dmr handheld. I am looking at radioddity GD-77, Aliunce HD1 x? Or the retevis rt3s or maybe you could recommend one? I have had the anytone 878UV plus and md380.. So something preferably moddable with a promiscuous mode perhaps as I mainly listen to business radio stuff. Thanks for sharing and always appreciated subbed Any help appreciated i

@radiosification Жыл бұрын

I haven't tried it myself but most people tend to recommend the anytone d878uv or whichever their newest model with a similar name is as the best dual band dmr radio for hams

@RADIOPROFI Жыл бұрын

As I wrote earlier, sfr well supports the Kydera emesh model and Belfone bf-td930

@radiosification Жыл бұрын

🙂

@user-yt9je8sq8l 6 ай бұрын

The Hytera SFR implementation has one disadvantage to SFRs using DCDM Split TS as in the Hytera implementation if two or more mobile subscribers (MS) are within simplex range of each other then I believe they will hear each other directly when on receive and depending on what the particular MS manufacturers do with the SFR signal being received as well then possible audio interference/cancellation may occur. I haven't tested this as I don't have the array of radios that 'radiosification' has, but I believe that this won't happen in a DCDM Split T/S SFR because of the TS synchronisation that will occur between MS & BS. This and other videos on this channel are very good as they aid understanding of DMRs more complex aspects but also provoke deeper thinking on the subject.

@radiosification 6 ай бұрын

Thanks. On good radio models, I didn't find any issue with the Hytera repeater. I think the Ailunce HD1 which I consider a cheap chinese radio had minor issues, like sometimes when transmitting it would get confused just after you let go of the PTT and it would play the signal in analogue momentarily. But if you have motorola and hytera radios, it works perfectly

@Rypcipypci 5 ай бұрын

I have tested this with 6 Hytera Radios plus one PD985 set in SFR mode - all in direct range - and it seems to be no issue with interference/cancellation you've mentioned. I used 4 x PD375 and 2 x X1P - all works great with this SFR, even if being in one room :)

@chamian1167 Жыл бұрын

The ailunce issue with the dmr audio being rx as analog (raw) form has also been experienced with my home brew SFR setup. No clue why it occurs though Edit: I'm interested to know if Motorola's SFR option in CPS does anything to Hytera SFR mode

@radiosification Жыл бұрын

The Motorola option doesn't seem to do anything, no. I think Motorola's SFR system works slightly differently and might need that box to be ticked. Not sure though. What's your homebrew sfr setup?

@chamian1167 Жыл бұрын

@@radiosification I've been just using two mobiles on DCDM mode as my SFR setup (similar to how you would have analog repeater set up from mobiles). works like gd88, better sound quality though and features range check (Private call to the repeater, repeater tx in group call which is included in rx group list). The radios are just on scan mode, works 99% of the time.

@radiosification Жыл бұрын

Sounds good! Can you explain a bit more how the range check works? Is it only to check if you're in range of the repeater or not when you transmit? So when you transmit to the repeater with a private call it fails if you're not in range?

@chamian1167 Жыл бұрын

@@radiosification Yeah pretty much the repeater’s Rx end is set to private call. So subscribers have to tx private call and they have rx group list set up to receive a group call.

@wrongsideof40 Жыл бұрын

Informative video. Thanks! I'm thinking about dabbling in some digital scanning and I wonder what your recommendations are for best 'bang per buck'. I also just saw your 'makeshift scanner' video, scrolling through the variables until you hit the jackpot. Is that how digital scanning is? Or are there options for radios that'll take all the guesswork out? Thanks :-)

@radiosification Жыл бұрын

The cheapest way to get into digital scanning is buy an RTL SDR and use that. There's lots of software out there these days that can decode the common digital modes. You can also just buy a digital scanner like the whistler trx1

@wrongsideof40 Жыл бұрын

@@radiosification Thanks for that. I actually have an RSP1 hooked up right now for analogue reception. Can you recommend some of the software that'll work with this, for digital reception, please? Thanks again

@wrongsideof40 Жыл бұрын

@@radiosification forgot to say I'm using SDR Uno with this, at the moment.

@radiosification Жыл бұрын

@@wrongsideof40 I don't have one of those so no, I don't know. I use SDR# with the rtl sdr but I'm not sure if it works with the RSP1

@JakobBuis Жыл бұрын

Great explanation, thanks for sharing :) I've looked into a new setup for our film-set use that get ever more complex, but being an all-volunteer organisation, this kind of shiny technology is out of reach for us unfortunately.

@radiosification Жыл бұрын

Thanks :) it's always fun to look at technology even if you can't justify buying it 😂

@JakobBuis Жыл бұрын

@@radiosification Yeah, def. I have a few notes on setups costing upwards of 20k, which was about 40x the budget. Still, it helped my get a feel for things I feel

@SloNicKTub 10 ай бұрын

Hello! Can you please tell me if several stations in SFR mode can work simultaneously, like a chain / network of repeaters?

@radiosification Күн бұрын

@@SloNicKTub I don't think so, because with only two timeslots one station would interfere

@rogersmith4926 20 күн бұрын

Did you try the duplex calling option, you are able to do a phone call to other Hytera-985 and mobile phones, did you try that? I read that in the description Would be interesting how that works, I'm thinking about buying one of these Hytera Talkies. But they aren't cheap at all. XD

@radiosification 20 күн бұрын

I don't have a second hytera radio to try a call with, but yeah it would be cool to try that

@rogersmith4926 19 күн бұрын

@@radiosification it should be able to do calls to a normal mobile phone, but I have no idea how. I know Wouxon does have Radios that work with sim card and dual band, would be interesting to try that out,

@timmy3-rr4kx Жыл бұрын

Were you able to test the Motorola as the receiving radio?

@radiosification Жыл бұрын

Yes I did another test that I didn't film where I talked between the radio shown on the left in the demo and the motorola radio via the SFR and it worked fine

@militaryrig 10 ай бұрын

@@radiosification How did you know it was going through the SFR? The tests I've done I can't get motorola or hytera to tx and rx on different timeslots to test it. When I turn the SFR off they still talk to each other even though timeslots are set different.

@radiosification 10 ай бұрын

@@militaryrig that always happens on a simplex channel because there's no source for when each timeslot starts and ends. There are essentially no defined timeslots in a normal simplex channel.

@radiosification 10 ай бұрын

@@militaryrig in my test I knew I was talking through the SFR because the hytera radio was high up and was the only radio that could have had signal to where I was. The other radio was indoors on the ground floor and would not work to the location I was at. Also I did a radio check to the hytera directly and it succeeded, so I knew I was at least in range of the hytera

@Jacob-mm8xq Жыл бұрын

How do the older MOTOTRBO radios do with this?

@radiosification Жыл бұрын

I haven't tried them but I would guess they should work okay because the subscriber radio (the radio using the SFR) doesn't need to have any special capabilities to use it or even know that it's using it.

@dennis8196 Жыл бұрын

The Aliance radio is extremely buggy, has an underpowered (or unoptimised processor) and fails far more often than my other budget radios, even the RadTel copies.

@radiosification Жыл бұрын

I've been quite lucky with mine then, not noticed many bugs. The one thing about it that I find annoying is that it always forgets the time and date and to turn it on after the internal battery runs out you have to try twice