NX-700 upgrade to P25

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tvsjr

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Kenwood is currently selling a programming option (probably a flash) to upgrade the NXDN NX-700 to its P25 cousin, the TK-5720. Has anyone performed this upgrade and might know how it's done? I have an NX700 gathering dust... it would be much more useful if it were P25-capable.
 

llu727

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I have never actually talked to anyone that has done this, but the price pages state the following:
KWD-P25C P25 Flash upgrade; NX-200/300/700/800
Must order L-1663
Note: KWD-P25C will be Kenwood factory installed only (units must be returned for upgrade) - $792.00
I would be interested in how it works, should you do it.

BJ
 

com501

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!!! I'm looking in the price book on Monday. Now I know what to do with those demos gathering dust in the back of the stockroom that nobody wants.
 
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syntrx

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Found this on retardreference. Hope you're not paying list!

FIRMWARE OPTIONS LIST
KWD-P25C P25 Flash upgrade; NX-200/300/700/800
Must order L-1663
List Price $792.00
Note: KWD-P25C will be Kenwood factory installed only (units must be returned for upgrade)

http://forums.radioreference.com/kenwood-forum/228878-nx-800-nxdn-p25.html

That said an NX-200 would make a very convenient small P25 radio.
 

com501

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Not anywhere near list, that sounds more like a board change than a flash upgrade. Sounds like the old BK P25 upgrade. Send us the radio and magic we'll 'make' it P25. Might still be worth it though for free demo radios....
 
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TheWizard

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This option has been out for at least a year or more now. It's funny how much more the IMBE codec costs over the AMBE... I'm not too sure why considering how much more versatile and robust AMBE can be, and heck it's a few years newer too. Is it because so many things run off AMBE now that they felt a price drop was in order?

Now if I'm not mistaken P25 Phase II uses AMBE.

At any rate, it may be a board change, it may be an EPROM flash that Kenwood does't want to get into the wild, then everyone woudl be changing their NXDN radio to P25 considering that Kenwood doesn't safeguard their firmware/DSP upgrades to the level Motorola does with iButtons and whatever else.
 
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n1oty

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I know nothing about this particular upgrade, but I do not see any need for Kenwood to switch out AMBE for IMBE. I have two new UHF EFJ 5100es radios with the AMBE vocoder that talks perfectly with my Moto xts2500 IMBE radio. If anything, the audio from the EFJ's is slightly better.

John
 
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tvsjr

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The AMBE vocoder will function in IMBE mode. Kenwood has been using the AMBE+2 vocoder in their radios for a long time, for future-proofing.

And no, not paying list. Wish I didn't have to ship the thing back.
 
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syntrx

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This option has been out for at least a year or more now. It's funny how much more the IMBE codec costs over the AMBE... I'm not too sure why considering how much more versatile and robust AMBE can be, and heck it's a few years newer too. Is it because so many things run off AMBE now that they felt a price drop was in order?

Now if I'm not mistaken P25 Phase II uses AMBE.

At any rate, it may be a board change, it may be an EPROM flash that Kenwood does't want to get into the wild, then everyone woudl be changing their NXDN radio to P25 considering that Kenwood doesn't safeguard their firmware/DSP upgrades to the level Motorola does with iButtons and whatever else.

IMBE costs P25 manufacturers close to nothing, they pay a relatively small one time flat fee of about $100k to use it. P25 costs more than NXDN and TRBO simply because the manufacturers know they can charge more.

i'm guessing the upgrade requires more invasive means (JTAG programming or a board swap) to change the radio's firmware, hence why it needs to be sent in.
 
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ers404

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I was told it was a firmware change/upgrade and tweek to the RX/TX board. Kenwood only wants the factory to be able to do for all the obvious reasons.
Included in the upgrade is a new "P25" sticker and of corse a new S/N.
 
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TheWizard

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They can say what they want, I'm sure there's some tuning/alignment that should/must be done for "mission critical" type P25 radios considering the intended role they play as opposed to business grade NXDN; however, I think they do this for 'CYA' reasons. Consider the local dealer/repair shop doing this work. You know that the software is probably going to get leaked, just like firmware, software and everything else and how much fun it would be for us to have access to programs that can change serial numbers and what not... not going to happen when you plug the leaks by keeping things all in-house.

Now, I suppose a lab-leak ala Moto could occur or skeygen, but I'm not holding my breath because at least in my case I'm perfectly happy with what I have, how it is.
 

AFleetingGlimpse

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I used to work for a rather large Kenwood dealer. I was told it was a firmware bump that only factory techs had access too. (This was told to me by a factory tech at the time.) TVSJR is correct in that the AMBE vocoder will work IMBE just fine.
 
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TheWizard

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So, this is to say that if I tuned my NXDN radio onto a P25 channel, it would decode the audio?
 

Magnus

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No, there is more to it than that. Such as modulation scheme, p25 is C4FM or CQPSK not sure what NXDN is.
 

Astro Spectra

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NXDN is still CP 4FSK (continuous phase) 4 level modulation as is C4FM. But the 'deviation' is different; the four states of NXDN are represented by +/- 1,050 Hz and +/- 350 Hz whereas for P25 phase 1 they are +/- 1,800 Hz and +/- 600 Hz. This is why P25 Phase 1 occupies roughly twice the bandwidth of NXDN. The physics behind this is that the rate of changed of the modulation in NXDN is half that of P25 as less data needs to be sent.

In NXDN there are 2,400 symbol changes per second carrying 4,800 bits per second.

In P25 Phase 1 there are 4,800 symbol changes per second carrying 9,600 bits per second.

By the way the baud is the unit of symbol changes per second. Since each symbol represents two bits in a four level modulation scheme like 4FSK the data rate is twice the baud rate (and this is where all sorts of arguments of bauds vs bits per second come from).

References for interest:
http://en.wikipedia.org/wiki/Continuous_phase_modulation
http://www.nxdn-forum.com/resources/data/NXDN_whitepaper_201202.pdf

Of course the 'air interface' is so much more than just the low level modulation, there are all sorts of convoluted (indeed convolutional) processes that sit on top of the physical layer before audio gets to come out of the codec.



And to cut this long answer short, Magnus is right.
 
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