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Sunday, 9 January 2022

Comparison of digital PMR446 radios. dPMR446 and DMR Tier 1.

Old radios:
Radio model Digital mode Approx. price Waterproofing Notes Availability
Icom IC-F4029SDR dPMR - None First digital PMR446 radio. Discontinued. Icom recommends IC-F29DR2 instead.
Icom IC-F29SDR dPMR - IP67 (submersible) Icom IC-F29DR with display. Not officially discontinued but availability is poor
Icom IC-F29DR dPMR - IP67 (submersible) Discontinued - Replacement is Icom IC-F29DR2
Kenwood TK-3401D dPMR - IP54 (splashproof) & IP55 (water jets) Discontinued - Replacement is Kenwood TK-3701D
Kenwood TK-3601D dPMR - IP67 (submersible) Not officially discontinued but availability is poor
Motorola XT660d / XT665d dPMR - IP55 (water jets) Motorola's first and only digital PMR446 radio. XT665d includes LPD channels (low power, not PMR446 and they have worse range so not much benefit of having these channels). The dPMR association claims that this is not a dPMR radio, but I received a recording of the digital signal from someone who says they have this radio and it decoded using some software that decodes dPMR signals, so I think the dPMR association are mistaken and it is a dPMR radio (maybe just not certifiied by them). Discontinued - No replacement. Motorola only sells analogue PMR446 radios now.
Hytera PD355LF DMR - IP54 (splashproof) Discontinued
Hytera PD365LF DMR - IP54 (splashproof) Discontinued
Icom IC-F29DR2 dPMR - IP67 (submersible) Programming cable is about £50 and software (CS-F29DR2) is about £24. Discontinued. Replacement is IC-F29DR3.

Current radios:
Radio model Digital mode Approx. price Waterproofing Notes Availability
Icom IC-F29DR3 dPMR £192 IP67 (submersible) Programming cable is about £40 and software (CS-F29DR3) is apparently available from dealers. Icom says software from the last model (the IC-F29DR2) is not compatible so you have to buy new software (which is rather a shame because the radios appear to be functionally identical with the DR3 only having a more powerful speaker).This radio seems a good choice. Good availability
Kenwood TK-3701D dPMR £145 IP54 (splashproof) & IP55 (water jets) Programming software is about £20 and cable is generic kenwood style so many can be found cheaply. Range test video. A good choice. Good availability
Alinco DJ-PAX4 dPMR €180 IP67 (submersible) Programming software freely available online. Cable looks to be kenwood style so should be cheap. Seems like it could be a good choice. Good availability in EU only
Wouxun KG-D26 dPMR €199 IP54 (splashproof) Programming software freely available online, but it shows that it doesn't use common IDs as is recommended for dPMR446 equipment (so programming is more complicated). May work fine just for groups who will only use this radio out of the box and not need to reprogram to talk to other dPMR446 radios. At the price I wouldn't recommend it and would just go for the Kenwood instead if you only need IP54 rating. Good availability in EU only
Dynascan DA-350 dPMR (AMBE+2C) €175 IP67 (submersible) Uses AMBE+2C vocoder (not the standard AMBE+2 that most other radios use) so will not be compatible with other radios, except in analogue mode. Looks like a rebranded cheap Chinese radio so probably not as good quality as other brands. Could not find it available in the UK so price is in euros. Good availability in EU only
Hytera BD305LF DMR £97 IP54 (splashproof) Not so good build quality and uses DMR mode so worse range than dPMR. Not recommended. Good availability
Hytera BD505LF DMR £153 IP54 (splashproof) Not so good build quality and uses DMR mode so worse range than dPMR. Not recommended. Good availability
Hytera PD505LF DMR £178 IP54 (splashproof) Seems better build quality than Hytera BD series. Uses DMR mode so worse range than dPMR. Good availability
Hytera BP515LF DMR £144 IP54 (splashproof) Uses DMR mode so worse range than dPMR. Good availability

My recommendations

For PMR446 use, dPMR is better for most users because it uses 6.25 kHz channels rather than 12.5 kHz. DMR has to do some trickery to allow the same effective number of channels (32) which not all radios do, whereas with dPMR there are 32 channels by default. dPMR mode also gives better range. For these reasons I recommend people pick dPMR radios over DMR when choosing digital PMR446 walkie talkies.

I also don't recommend the Dynascan DA-350 because it looks like a rebranded cheap Chinese radio so the quality is dubious and it won't work with any other dPMR radios (unless they happen to use the same non-standard vocoder). I have the Kenwood TK-3701D and I can recommend it. It works very well and is much better value for money than the Icom if you don't need IP67. I haven't tried the Icom IC-F29DR3 or the Alinco DJ-PAX4 but they also look like good options especially if you need IP67 rating since the Kenwood is only IP55. Out of the Icom and Alinco I'd probably go for the Alinco because it has programming software that is free and the Icom programming cable is expensive.

If you find any radios I've missed off this page or if any information is out of date, please leave a comment (or email me using the details on my contact page) so I can update it.

This page was last updated 02/07/2023.

Chinese dPMR radios comparison

Names Type Vocoder / Vocoders Availability 3.125 kHz steps Compatibility group Notes
Puxing PX-508D, Puxing PX-558D, Radtel RT-14D, NRC DigiA Handheld, no display or keypad AMBE+2C Poor Yes 1
Zastone ZT-9908 Handheld, display and keypad AMBE+2C Poor 1
TYT DM-UVF10, Retevis RT2 Handheld, display and keypad AMBE+2C Poor 1
Puxing MD-500 Mobile AMBE+2C Poor
BFDX/Belfone BF-P108 Handheld, no display or keypad RALCWI Poor
BFDX/Belfone BF-P118, Luiton DG-1180 Handheld, display and keypad RALCWI Poor
Kirisun S780, Kirisun FP460 Handheld, display and keypad ASELP Poor Yes 2 Poor range - bad receiver sensitivity.
Kydera DP-550S Handheld, display and keypad AMBE+2C, ASELP Poor No. Rounds to nearest so 446.103125 becomes 446.1 Terrible audio quality - very muffled sound. Does not work with other dPMR radios.
Recent RS208D Handheld, no display or keypad ASELP Good 2
Recent RS209D Handheld, display and keypad ASELP Good 2
Recent RS308D Handheld, no display or keypad ASELP Good 2
Recent RS309D Handheld, display and keypad ASELP Good 2
Sainsonic FM-416, HYND DP320 Handheld, no display or keypad Probably ASELP Poor
Recent RS-619D Handheld, display and keypad Probably ASELP Good
HYND DP330 ASELP, AMBE+2C Good
HYND 500(DPMR) ? Good Be careful, they also sell a DMR model of the same radio with the same model number.

Vocoder
The vocoder is the part of the radio that converts your voice into very low bitrate digital data so it can be sent over the radio channel efficiently. Each vocoder will sound different because they make different sacrifices to compress the voice. I wrote a page about different dPMR vocoders here. Some radios are available with multiple vocoders so you have to make sure to get the right one. The only way to tell is usually by trying it, or sometimes the seller or manufacturer will be able to tell you. They often don't know much about their products though.

3.125 kHz steps
For a radio to work on dPMR446 channels it needs this. If not, it will be on the wrong frequency. The radios on this page are not legal to use on PMR446, however it is pretty common for people to program chinese radios to use PMR446 frequencies and as long as you fit in by using the right frequencies and bandwidth then it probably won't be noticed. Therefore, if you're planning to use one of these radios on PMR446 digital frequencies then you should get the one with 3.125 kHz steps.

Compatibility group
This is a term I just made up for this page. Radios in the same compatibility group should be able to talk to each other. This is not guaranteed as I have not tested them all and specifications (including vocoder) are sometimes changed even for the same model number.
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If you're trying to buy any of these radios, aliexpress, eBay and alibaba are usually good places to search. eBay is usually the easiest as they will post from your country but only the most popular radios usually get listed there. Aliexpress is the next best but they post from China so it may take a long time to arrive. I have linked some of the names to the product page on aliexpress.

Please leave a comment below if you have information missing from this page that I can add.

Thursday, 16 July 2020

Quansheng UV-R50 programming software download

I found it very difficult to find this software online so thought I'd provide an easily searchable download link. For some reason it installs itself as TG-Currency03.exe. They probably just didn't bother to rename it from a default. So you'll need to look for that to open it once installed. I suggest you rename the folder during the installation to something sensible, so you know what it is later on.

If you're going to link to the download then please link to this page as I may change the download link if it breaks, and then your link would break too.


The original link to the Quansheng website where this file is from, is below. I provided this just in case it actually stays up and doesn't break. It might be a good idea to try this link first because it may have a more up to date version of the software. 


Wednesday, 13 May 2020

Tuning your hotspot (Pi-Star)

Tuning your hotspot is something you should do to get the lowest BER (Bit Error Rate) - that means to get the least errors in the digital data being sent by your radio. If you have a high BER then it causes your audio to sound bad to others or even to fail to decode if it's very badly tuned.

So to do this, first open up the dashboard of your hotspot. This can be accessed at pi-star/ usually. Then click on configuration near the top right of the page.

Next, in the same area click on Expert, then MMDVMHost. Scroll down on this page to the Modem section. You should see an RX offset field.

Now, set your radio to use a talkgroup/room/reflector where you won't be disturbing anyone by transmitting. I suggest using an echo test one. On the Brandmeister network this is done with a private call to 9990.

Open a new tab in your browser and navigate back to the dashboard. When you transmit, you should be able to see it under the Local RF Activity section. If you don't then it could mean that your frequency is off by such an extent that the hotspot isn't even detecting the transmission.

From here you can start tuning up and down on the RX offset frequency. I'd recommend going up or down in 100 Hz steps at first. Each time, save the new RX offset and transmit again for a few seconds. See if your transmission comes up under Local RF Activity. Look at the BER and write it down along with the RX offset. After some trial and error, you should find an offset that gives the lowest BER. If you are still increasing/decreasing the offset and the BER keeps going down, then keep going until the BER starts to increase again. At the minimum point, you've found the correct offset.

At this point you can either tune it further, by going up and down in smaller steps than 100 Hz, or you can just stick with the current offset. I'd recommend tuning it more if you have the time.
If you choose not to tune it further, then you're done!

Wednesday, 23 January 2019

dPMR vocoders

Kirisun S780. An example of a cheap Chinese
dPMR radio with the ASELP vocoder
There are a number of vocoders commonly used in dPMR. For those of you who are not familiar already with what a vocoder is, here is a brief explanation: A vocoder converts the voice signal into low bitrate digital data so it can be sent over a radio channel, and then converts it back to voice at the other end. This allows the voice to be sent in less bandwidth than if some other audio codec that is not optimised for voice (MP3 for example) was used, or even than analogue modulation. A vocoder is just an audio codec that was specifically designed to be optimised for voice, and usually will not accurately represent other sounds.

The dPMR standard has two bits allocated to denoting which vocoder is in use, allowing four choices. This is specified in the dPMR Mou tech.lib-Voc Bits-v1 document. The options are:

1. (00 in binary) Standard vocoder. AMBE+2.
This vocoder is very widely used in digital PMR/LMR products including in DMR, P25 Phase 2, and NXDN. It is a solid choice of vocoder, but far from the only choice. A sample of how this vocoder sounds can be heard at the start of this video. All Icom and Kenwood dPMR radios use this vocoder and are guaranteed to work together because they have been through interoperability testing.

2. (01) Vocoder to be selected by the Chinese DRA.
According to one commenter on this article, the DRA is a Chinese entity but seems not to have produced anything since 2010. I did some further research (originally for this article) and found out that DRA stands for Digital Radio Association. It seems they originally intended to create a dPMR based radio standard called NDR, using their own vocoder. dPMR radios with this vocoder could be sold as NDR radios, presumably to assure users that they would be compatible with each other.

I could not find any information about this vocoder online. I requested information from the dPMR association and they did not know what it was either. My guess is that the DRA and their NDR project got abandoned.

If any vocoder was selected, I believe it's highly likely that the ASELP vocoder would have been the one chosen. This is because it's a Chinese developed vocoder. See more information later in this article.

If you have any further information then please leave a comment below or contact me.

3. (10) RALCWI vocoder.
I have never seen a single dPMR radio using the RALCWI vocoder. I cannot even find any samples of what that vocoder sounds like online. I contacted the company that made this vocoder, asking if they had a sample, and if they would give me permission to post it. They said that they do have a sample but that "audio samples are only made available to known equipment manufacturers with a defined relevant project." My guess is that this vocoder must not sound very good, because other vocoder makers usually want to show off how great their product sounds.

4. (11) Manufacturer defined vocoder.
This is probably the second most used choice after number 1. Although the certified dPMR radios all use the standard vocoder, many Chinese manufacturers have been using the dPMR standard to create fairly cheap digital radios, however their radios have not been certified by the dPMR association so are not guaranteed to work with other dPMR radios. The manufacturer defined vocoder is not one specific vocoder. It can be any other vocoder that the manufacturer selects.

Other Vocoders

The vocoders that I have seen in use (with, I assume the manufacturer defined setting), are ASELP and AMBE+2C. More information is given below.

ASELP
A vocoder developed by the Chinese Tsinghua university. ASELP stands for Advanced Sinusoidal Excitation Linear Prediction and is not to be confused with ACELP, the vocoder used in TETRA. This vocoder was developed because of the desire for a vocoder with intellectual property rights that were owned by a Chinese organisation. There is not all that much information on this vocoder online in English, however you can read my attempted translation of the journal article describing this vocoder.

ASELP is commonly used in Chinese made dPMR radios and sounds fairly good. A sample of the vocoder as implemented in the Kirisun S780 can be seen in this video.

AMBE+2C
This vocoder caused a bit of confusion for dPMR enthusiasts because nobody seemed to know who it was by, if it was the same as AMBE+2, or if it was just a name made up by the Chinese manufacturers to trick people into buying their radios (which would not be surprising because Chinese radios are commonly listed online with exaggerated output power and specification claims).

I contacted DVSI, the company who made the AMBE+2 vocoder to ask them about AMBE+2C. They told me that it is their vocoder. It is made as an alternative to AMBE+2 but is not compatible with it. Although I was not given pricing information, I would guess that this vocoder is cheaper than AMBE+2 and that's why it is commonly used in Chinese made dPMR radios. It is available through a software licence.

My advice
If you're looking to buy dPMR radios then I recommend that you buy radios using the standard vocoder. These are sold by Icom and Kenwood, and they are all good quality radios. The dPMR radios sold by Chinese manufacturers are cheaper, but the quality is usually nowhere near as good, and you cannot rely on them to work with each other. Even within the same model of radio, the vocoder is sometimes changed, so if you need to buy a new radio later on then you might find that it won't be able to communicate with the older ones.

Wednesday, 16 January 2019

Jumbospot ethernet adapter

A cheap Chinese ethernet adapter

If you're thinking of getting an ethernet adapter for your jumbospot hotspot, watch out. The cheap Chinese ones on ebay (usually marked with the number 9700) have issues. See this link for full details. The short version is that they're only USB1 so are very slow, and they have a poor design that makes them perform sub-optimally.

They still work but it might not be as good as a properly made and supported ethernet adapter. The slow speed is generally not too much of a problem since hotspots don't need to transfer data at a high speed most of the time anyway. Digital voice is low bitrate, which means it only needs low speeds.


They should work out of the box, assuming you have a relatively up to date version of pi-star installed. I had to restart the hotspot to get it to work. I also noticed the dashboard loading much quicker than on Wi-Fi so even with the slow speed and poor design, it might be better to get one of these than relying on Wi-Fi.

Still, it would be better to buy one which is properly supported, like the 3 Port USB Hub w/ Ethernet - Micro USB (Pi Zero) sold by ModMyPi, Pimoroni and other retailers.

Update (19/04/2019): After about three months of use, I haven't had a single issue with this ethernet adapter. Although in theory they might not be completely optimal, I find that in practice they work perfectly adequately for hotspots. Hotspots generally operate at a low data rate, so the fact that this product only supports USB 1 isn't an issue for this use case. I recommend this product if you want to connect your hotspot by ethernet cable for more reliable connection to the internet.

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