Custom Search

Friday, 28 June 2013

Kirisun S780 information on vocoder and standard

I'm very interested in this radio because it is a cheap way to try out digital, so I have been looking through the internet and contacting manufacturers and resellers about this product and thought I'd create a post to show everything I've found out that you might want to know.
The radios are available on 409shop for $128, or on ebay for $140 or £90.

So here it is:


Vocoder: BBMR. Apparently developed by a Chinese university. (According to 409shop, who told me that that is what the factory told them)  Must be a lower cost alternative to AMBE and RALCWI.
I have recently found out that the Chinese manufacturers have access to a chip that includes the vocoder, the Linktop LT1801A ASIC (That's Application Specific Integrated Circuit).
It includes the CPU+DSP+VOCODER+DAC+ADC apparently.
Terms explained:
DSP: digital signal processing
DAC: digital to analog converter
ADC: analog to digital converter
It is possible that this chip is used in the radio, but its difficult to extract information from anyone in the Chinese PMR industry!
Standard:
It uses 6.25KHz FDMA (so not DMR compatible)
It appears to be either dPMR with a different, manufacturer chosen, vocoder, or NDR. (NDR is actually still dPMR, but just with a certain set vocoder)

On this dPMR document, it talks about different vocoders which can be used by radios folowing the dPMR standard. The default one to use for the dPMR standard is AMBE+2, then it mentions the RALCWI vocoder, and there is something about another vocoder which will be selected by the Chinese DRA (Digital Radio Association), who are going to be going through a selection process to choose a vocoder for NDR (narrow digital radio). Finally it says that a manufacturer specific vocoder may be used.

After some further research, I have discovered that dPMR, NDR, and DCR (Japanese version), are all the same thing, but with slight variations. The second two (NDR and DCR) both conform to the dPMR standard, but have a slight variation, for example, the vocoder is different for NDR radios. They are like sub-standards, as in they follow the main standard, but specify their own vocoders.
I think this was made so that manufacturers can simply call their product an NDR radio if it uses the vocoder chosen by the DRA, or a dPMR radio if it uses the AMBE+2 vocoder.
It is possible that this radio follows the NDR standard and the vocoder used in this standard is BBMR, but this is not confirmed. I cannot even find any information on the NDR standard itself.

Which standard it follows is important because it decides whether it can communicate with other radios of that standard. Even when radios are using different vocoders, if they are both the same standard, they should be able to send text messages and status messages between one another.

Other info
If you want to see a video of it in action, there are now a few videos on YouTube, the easiest way to find them is via a search

There are also these photos from the Russian website 5radio.ru. Credit goes to them.
Check their website for a few more photos of the menus. http://5radio.ru/index.php?productID=1783



Finally, a good source of information is the yahoo group on this radio: http://groups.yahoo.com/group/S780/

13 comments:

  1. Hi, i have recently purchased some of the Kirisun s780 radios and have a few questions.
    1) is it possible to replace the belt clip with a klick fast stud? (police/ambulance style holder)
    2) how long do you recommend charging for, on the first charge and once in use.

    Thanks

    Sean

    ReplyDelete
    Replies
    1. 1. I doubt they make them for these radios but you could possibly find one that fits, or just stick one on with superglue on the back of the radio.
      2. Don't know. Check the manual. I just charged them up normally but the manual could recommend something else. I didn't bother reading it though.In fact, I can't even remember if there is a manual!

      Thanks for your comment

      Delete
    2. Hey, thanks for your reply, just did the same in the end, charged as normal. and as for klick fast items i can tell you (if anyone else wants to know) the sepura case fits great.
      also do you know anyone using these up near north wales area? and after testing i noticed range is quite terrible have you any tips on how to improve it? trying to use these over approx 3 mile radius and i can only get about half a mile if that.

      Sorry for all the questions

      Thanks

      Sean

      Delete
    3. Yeah, unfortunately the range of these sets on digital is just not good. Theres not really anything you can do. You'll get a better range on them if you use analog. Its a shame because everyone expects digital to have a better range, but in this case the range is much much worse on digital than analog.

      Delete
    4. This depends on witch anttena is used there a 2 with the radio us one with the most close frequency of choice. I mostly use the short one because the frequency that we use is in the 460 Mhz.

      Delete
    5. Well, compared to any other radio on the same frequencies with the same antennas, it does have significantly worse range.

      Delete
  2. Do you think these would be good for communications for race communications. Pit - Car coms?

    ReplyDelete
    Replies
    1. Honestly I wouldn't rely on them for something important

      Delete
    2. Pit to car comms is quite simple, analog will be fine for that purpose. Digital is only really useful when you have more complicated signalling needs, such as a need for ptt ID, trunking, different talkgroups on the same channel.

      Delete
  3. Have you got any idea to talk the Kirisun S780 wiht KYD DP-550S or MYT2081 ?

    ReplyDelete
    Replies
    1. I wouldn't bet on it. Don't trust any chinese digital radios to use the same vocoder, unless they specifically say. Even then, there is sometimes trickery involved, such as the Zastone ZT-9908 claims to have to AMBE+2C vocoder, which seems very similar to the AMBE+2, but it won't work with it.

      You never know what vocoder they'll actually use.
      I'd say as a guess that they won't be able to talk to each other.

      Delete
  4. Thank you for the reviews on this radio- convinced me to buy two units. However, I cannot find the programming software anywhere. Is there link I can access?
    Thanks
    Tony.

    ReplyDelete
    Replies
    1. Yeah, go on the yahoo group, in the files section. There is software in there. Link to the group is there at the end of this post.

      Delete

Please note: Comments with links to your own blog or website will be deleted if not relevant to the post.

Popular Posts