P25 simulcast on TK-5520 using KPG-112DN

[RobertI]

I'm a Motorola guy so Kenwood terminology and CPS is a learning curve.

Where do I verify the TK-5520 is correctly set for simulcast in KPG-112DN software? VHF P25 multi site repeaters, non trunking.

On my Motorolas, forgot to change "Digital Modulator" to "CQPSK" so I was having poor reception. Many thanks to @KevinC for pointing out my senior moment.

Thanks folks!

PS: As I said, Motorola guy, but what's the firmware update like on the Kenwoods? Big M is big M so I know it's a project with those.

 

[mmckenna]

I believe it only supports C4FM. None of the documentation I have shows CQPSK as an option on those radios.

I think you need to step up to the NX-5000 line of radios to get that.

 

[RobertI]

I couldn't find anything despite my best efforts searching every software option. Certainly not the answer I was hoping for, so unless someone else has a work around, I'll just deal.

The problem is, it's not my radio to upgrade, but I now know why I got it. I don't feel like getting into the politics of it, so let's just leave it there.

 

[kd4efm]

Did a little more digging,
The TK-5x20 series was basically a upgrade NX series to P25 C4FM. LSM (kenwood's verbiage to CQPSK) is called Linear Simulcast Modulation.
The TK-5x10 Series was the same way but had a little more options for it, but lacked LSM also.

The introduction of the VP/NX-5000 series, was capable of doing C4FM or LSM both Trunking, and Conventional channels.
The VP-6000 series followed suite as well.

The Viking Vp600, 900, did have the ways for simulcast modulation. As for the OLDER 53 series I don't know, as I came in on the VP/VM600-900 time frame as I was also kicking with the NX-x00 series when it came out in 2008, after I did my elmering stint with D-Star.

 

[RobertI]

That's quite a thorough dig, and I appreciate it. Even if it just reinforces that I'm SOL, it's good to know why. A very solid reason for me to get a radio that's actually compatible with the system. Do you have a document that shows the omission of Linear Simulcast Modulation? Or a spec sheet showing what LSM is and the TK-5520 not having it? I'd ike to print it out. Some leverage.

In your opinion, what symptoms would I see on my HT given it doesn't support simulcast/LSM? On my Motorolas, it was messy random reception until I checked off CQPSK. The Kenwood isn't completely unusable, but it's far from good. I leave it home most days because it's not worth clipping on my belt.

I won't quote you on it. If pressed, I'll say I did my own digging, which isn't a lie. I did ask here. 😏

 

[kd4efm]

in simple words, as I see it, Think of it as Gen 1, Version 1 gear, before Simulcasting came into play. I am going to find out from T.S. if there is
or was any updates to include LSM on either the 5x10 or 5x20 (nx-x00 series) that allows LSM algorithm.

 

[RobertI]

That would be very much appreciated. Unofficially spoke with someone and was unofficially told, you get what you get. Be thankful. 🙄

Yeah, the bottom of the junk box...

 

[RobertI]

In comparison, only ever seen APX. Thought that's what I was getting. Surprise, and not a good one😂

 

[GTR8000]

For some reference, LSM (Linear Simulcast Modulation) was developed by Motorola many years ago, and the first practical use of it for P25 systems coincided with the introduction of the G Series repeaters in the late 2000s that featured linear power amplifiers.

US5541953A - Data transmission method and apparatus for use in low BW:Rs applications - Google Patents

A data transmission scheme for use in a low channel bandwidth-to-modulation symbol rate ratio (BW:R S ) application employing a linear modulator for producing in-phase and quadrature (I and Q) components of a data stream inputted at a predetermined symbol rate. This transmission method allows...

patents.google.com

http://www.simulcastsolutions.com/userfiles/file/simulcastforums/motorola_simulcast_part4.pdf

 

[KevinC]

For some reference, LSM (Linear Simulcast Modulation) was developed by Motorola many years ago, and the first practical use of it for P25 systems coincided with the introduction of the G Series repeaters in the late 2000s that featured linear power amplifiers.

US5541953A - Data transmission method and apparatus for use in low BW:Rs applications - Google Patents

A data transmission scheme for use in a low channel bandwidth-to-modulation symbol rate ratio (BW:R S ) application employing a linear modulator for producing in-phase and quadrature (I and Q) components of a data stream inputted at a predetermined symbol rate. This transmission method allows...

patents.google.com

http://www.simulcastsolutions.com/userfiles/file/simulcastforums/motorola_simulcast_part4.pdf

Getting a little OT, but the STR3000 supported LSM and was basically an iDEN BR.

 

[RobertI]

That PowerPoint presentation is outstanding. Nice find. Enough pretty pictures clearly intended for the admin staff to not deep sleep through 91 slides. Even a chief could understand it!

*looking for projector*

 

[kd4efm]

Okay here is Kenwood's response to the LSM on these radios.

Evans,

The TK-5x10 and TK-5x20 series will support LSM by default in production firmware. Nothing special is required.
In order for the radios to work well the system must be in good standing.
That said, LSM was adopted after those radios were designed. In marginal conditions the radios may not work optimally.

 

[KevinC]

Okay here is Kenwood's response to the LSM on these radios.

Evans,

The TK-5x10 and TK-5x20 series will support LSM by default in production firmware. Nothing special is required.
In order for the radios to work well the system must be in good standing.
That said, LSM was adopted after those radios were designed. In marginal conditions the radios may not work optimally.

I would venture to guess the overlap areas are where it will have the most issues.

 

[RobertI]

Now that's going above and beyond *deep bow*

They could have shortened that reply.
"It'll work but it will probably suck"

I can confidently say the system is in excellent standing. And if they mean in marginal conditions at my house, as in within +/- 5 miles of 2 towers of a 5 tower system, then yeah it's marginal. I'm sorry I'm not in the shack at the tower base.

Reading between the lines, my takeaway is:

"Yes, the radio can get the transmissions but because it's so old it probably won't work as well as radios specifically designed for it (evil Motorola gear). Your mileage may vary, but it's likely to be in the single digits unless you're sitting right on top of it. May the Schwartz be with you."

I very much appreciate the effort everyone, but this is honestly not worth it. It's entirely possible the radio hasn't been aligned in countless years. Getting even that addressed will likely be a non-starter, but I'll try.

Oh, and another demonstration of how much the programmer didn't care, it had a whole host of other frequencies, some defunct, others with a dyslexic NAC or Pl, and one that just never licensed in the state but it had a label and pl and everything. Wonder what was going on on that...

Now that I have something I own working properly, I'll do something but I won't say what.

Thanks everyone. I owe you all a round 🍻

 

[kd4efm]

I would venture to guess the overlap areas are where it will have the most issues.

Hard to say, we are not there to troubleshoot the system freelancing. But I would venture to say yes Kevin.

 

[KevinC]

Hard to say, we are not there to troubleshoot the system freelancing. But I would venture to say yes Kevin.

That’s just from my experience with users having it set wrong in a MSI subscriber (C4FM vs CQPSK). But I’m sure someone will tell me how wrong I am. 😁

 

[AM909]

That’s just from my experience with users having it set wrong in a MSI subscriber (C4FM vs CQPSK). But I’m sure someone will tell me how wrong I am. 😁

Same thing happens when trying to decode with DSD+ the output of SDR#'s standard FM demodulator. It sort of works, depending on the sites and signal strengths, the phase of the moon, etc.

 

[wd8chl]

Umm...what is a TK5520? I work for a Kenwood dealer, and I've never heard of it?
(And how come no else asked?)

 

[RobertI]

That's why I asked. There was almost information specific to that model, only the series. On paper it doesn't seem like a bad radio. The feature is seem there (minus the simulcast obviously), but in all honesty, it kind of sucks. It's fat, clunky, pretty uncomfortable to hold. It's like holding a slippery rounded half brick, about that size and weight too. I'm thinking best suited for a speaker mic

 

[mmckenna]

Umm...what is a TK5520? I work for a Kenwood dealer, and I've never heard of it?
(And how come no else asked?)

It'a typo, TK-5220. Essentially an NX-200 with the P25 firmware loaded in it.