Kydera DR-880UV Plus / Radioddity GD-88 firmware

This post was originally intended to be a repository of firmware for the DR-880UV Plus radio since Kydera does not have a page on their website like other manufacturers do to provide updated firmware. However, now that Radioddity has started publicly releasing new firmware that works on both brands, I've started using it to provide more details on their newest firmware.

If you want to share the any of my downloads (not the ones on Radioddity's website), please link to this page rather than the mega.nz link directly because I will update it with new ones in the future.

How to use

To apply the firmware you need the IAS software and the programming cable. Turn off the radio, connect it with the programming cable and then turn on the radio while holding the top side button. It should show a different screen from normal with A or B on the top. You can change between A and B by holding the top side button again.

Then use the IAS software to load in the A firmware with A on the screen of the radio. Switch it over to B and then load in the B firmware. Each firmware package should have two files in - one for each of A and B.

Versions

September 2022 Version

Screenshots of radio (one for each VFO. The firmware is different for each):

It's interesting to note that this version says GD-88 V1.0 at the top line when opening the versions on the radio.

Issues I've found with this firmware:

• Volume is way too loud even on minimum.
• Screen backlight setting (BL Switch) keeps resetting itself to BL ON after I set it to auto.
• Wrong ham contact shown. If two people are talking it keeps showing the details of the first one.
• VFO B keeps changing its step back to 5kHz. I've changed it to 6.25kHz about 10 times now.
• Recording feature just stops recording even though it's still turned on in the menu. Can't get it to resume recording even if I turn it off and on.
• The Single frequency repeater (SFR) is buggy. Half the time it doesn't pass audio. It always sounds muffled and quieter than the original audio so it seems like it's being transcoded even though it shouldn't be.
• Analog APRS can lock up the radio and it continues transmitting until you pull the battery out. I think this occurs if the message you set is too long.

Download link

October 2022 Version

This one is from Radioddity and shows as Oct 27/28 when loaded to the radio. It still shows as GD-88 V1.0 though. It works on the DR-880UV/Plus.

Changes:

• They've changed the version display so you can see the version of both A and B VFOs on one screen now (instead of two separate screens like in the photos for the previous version). 
• Includes talker alias! Excellent feature so you don't have to load the ham contacts database and keep it updated. The radio will now transmit and receive talker alias on DMR.

Download direct from Radioddity: https://www.radioddity.com/pages/radioddity-download

Click on the GD-88 then download 2022-10-28 Firmware B49E.D64.EHRSAB.007.

November 2022 Version

Changes:

• Supposedly fixes the ham contacts database. I've loaded the firmware onto my radio and it does seem to be better. It would previously get stuck on one contact and show that contact for everyone else until you restarted the radio.
• Adds support for programming cables based on the FTDI-chip. Most people won't notice the difference but if you had a programming cable you thought should work but didn't, it might now work after updating the radio to this firmware. The problem is you'd need a working cable to update the radio first anyway.
• "minor fixes within the Talker Alias display". Not sure what Radioddity meant with this one. It seems to be working just the same for me. They didn't provide any more detailed information about what they fixed.
• "Assignment of 1450 Hz Pilot tone fixed (does require at least CPS 3.3 DMR CPS_DRS [9.2.16])". Again not much detail provided by Radioddity on this one. I'm guessing the 1450 Hz tone which is needed to speak through some analogue repeaters wasn't working before and now it is.

See Radioddity's page on it here: https://www.radioddity.com/blogs/all/bugfix-for-radioddity-db25-d-and-gd-88

I think I heard someone mention in a discussion that if you put this firmware on a Kydera radio it will brick the radio (make it stop working), but it works fine on my Kydera DR-880UV / Plus. I'm guessing if you have the non-plus version (Kydera DR-880UV) it would probably not work.

Download direct from Radioddity: https://www.radioddity.com/pages/radioddity-download

Click on the GD-88 then download 2022-11-20 Firmware B49E.D64.EHPSAB.010.

March 2023 version

Changes:

• DTMF is supported now
• Single VFO mode added
• "DMR-audio level aligned to analog-audio level" Still too loud on both at minimum volume.
• Talkgroup will be received now if programmed as the contact for a channel
• "Current entry of menu or submenu and the total number of entries are displayed in the upper right corner above each other" Still hard to use. They should just replace it with an extremely simple text based menu.
• "RXGroupList’ menu within ‘Device Info’ now displayed correctly" To be honest I hadn't noticed there was an issue with this before.
• A few other minor things. You can see the rest in the release notes provided within the update package.

I actually made an update video based on the state of the radio with this firmware update applied:

Download direct from Radioddity: https://www.radioddity.com/pages/radioddity-download

Click on the GD-88 then download 2023-03-30 Firmware. Or direct download link here.

June 2023 unofficial version

This is not an official Radioddity or Kydera released firmware. This is one I got sent by a radio dealer I know, who got it direct from Kydera after he showed them my videos complaining about the radio's problems. They made this firmware to address one of those problems. 

I expect they will include the changes in the next official firmware release.

Use at your own risk! I have tested this on my own radio and it worked fine, but I don't take any responsibility if it causes issues with your radio!

Changes:

• Analog and digital audio are now at a much lower volume when the volume is set to the minimum level.
• There may be other changes - I haven't tested everything and no changelog was provided by Kydera.

Download link had to be removed after a request from Kydera to take it down. It turned out they had used the radioddity model number (by mistake I think) in this firmware even though they sent it out via Kydera. I think that's why they wanted it not to be shared anymore (but I'm not 100% sure). The Late June 2023 version below seems to be almost the same anyway so if you were looking for this update then just use that one instead.

Late June 2023 version

This one is an official Kydera firmware. I've had one person verify it also works on the Radioddity GD-88 which is usually the case with all of these firmware releases.

This has just come out on 03 July 2023 even though the date in the versions info shows June.

Changes:

• Analog and digital audio are now at a much lower volume when the volume is set to the minimum level.
• There may be other changes - I haven't tested everything and no changelog was provided by Kydera. Please let me know in a comment or by contacting me using any of the details on my contact page if you find other changes from the last firmware.

This is an official release this time (so I shouldn't be asked to remove it), so here's the download link.

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.

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.

https://mega.nz/file/ZNwRkbzI#4srxAMaqACmBZFrLeoJFWEW2kzd_Eava56Rj23o3Pu4

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. 

http://www.qsfj.com/products/459

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!

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.