P25 (astro) mode across different brands..problem.

[Elroy Jetson]

I set out to make two radios operate in digital mode on the same channel. P25/Astro mode, of course.

One radio is an Astro Saber and the other is a M/A-Com P7100IP. Both have the right options and this should work.

Despite many attempts and changing many options around, the best I've been able to manage so far is a one-way link.

The Astro Saber's transmissions are always correctly decoded by the 7100, including group and unit ID numbers,
but nothing I've attempted yet (including selecting the digital CSQ option) has made the Astro Saber decode the
digital transmission coming from the 7100.

I've done everything including analyze the modulation of the two radios to be sure they're in spec. They are.

I can't see why this isn't working...but if you've got some ideas, I'd love to hear them.


Elroy

[escomm]

This may seem silly but how far apart are the radios? I seem to recall a similar thread some time ago and the problem was the radios being too close to each other.

[Elroy Jetson]

Interesting...I'll check it out.

Elroy

[GlennD]

Tait was trying to sell my city some radios. Their 9100 worked fine with our UHF XTS3000s and XTS5000s.

[Hightower]

This may seem silly but how far apart are the radios? I seem to recall a similar thread some time ago and the problem was the radios being too close to each other.

My 5K could not TMS a 2.5K 4 feet away, yet the 2.5K could send messages to my 5K no problemo. Once we departed, we could send TMS's not problem. We were out of P-25 range, yet messages keep making it through......

P-25 voice was no problem between the radios 4 feet apart however.

Have you check the alignment on both radios? Alignment is very important for IMBEEEEEE!!!!

[libuff]

This may seem silly but how far apart are the radios? I seem to recall a similar thread some time ago and the problem was the radios being too close to each other.

is this why FDNY Digital Fire Ground failed?

[nmfire10]

There are a lot of reasons P25 is a bad idea on the fireground. If this is a actually a problem, then I'm sure it is on the list.

[RESCUE161]

What is the firmware on the Astro Saber? Even if it's old "non-IMBE" firmware, it will still TX P25 fine, but will not decode it.

[Elroy Jetson]

The firmware is "up to the minute, version 7.7 or something in that range. I'm not motivated to go read it off the radio right now because it's been
a long day and I don't disturb radios when the batteries are being recharged, but be sure that the firmware is nearly up to the minute.

I know that the ASIII was recently aligned...I did the full alignment myself. And yes, I DO have all of the necessary equipment to do it properly.
All of my test and measurement gear is excellent, and recently calibrated or referenced to a calibrated source.

But I haven't aligned the 7100 yet. Since I only just got a service manual that explains the procedure, I guess I'll be doing that shortly.

Truth be told....in many respects, the m/a-com radios like the Jaguars, 7100s, and LPEs are considerably easier to hack than many Motorola radios.
For one, the radio maintenance software allows you to swap things around pretty easily. No special tools required to change a radio from no display
or keypad to a display model with no, limited, or full keypad.

And here's something interesting....on the jaguar and 7100 radios, the features are keyed to the ESN. The ESN is stored permanently in a single
small integrated circuit on the board. If you had, say, a useless low split UHF 7100 with some cool features in it, and an 800 MHz radio that could
use the feature package that was in the UHF radio, swapping the ESN chips first, and then exchanging the feature encryption data by the radio
maintenance software, is all you'd need to to to swap feature packages on the radios. Of course, the ESN would be different, too. I've got some
scrap boards (they can be read and programmed but have serious other problems) that have allowed me to "upgrade" some other radios in exactly
this manner.

But..the feature data string is half an encryption puzzle. The ESN is the other half. If they're not matched up, or edited with the aid of the RIGHT
software for calculating the new feature data string, you'll get errors and a radio that doesn't work well if at all.

Elroy

[escomm]

Did you try moving them apart yet?

[Elroy Jetson]

Did you try moving them apart yet?

It didn't help.



Elroy

[wavetar]

What letters preceed your Host/DSP firmware versions?

[Elroy Jetson]

R07.70.00
DSP N08.03.03
EMC R02.11

Whoreflashed, code 599108-1C5E00-1.

I think that's just short of the newest firmware radio code and DSP.

Elroy

[Hightower]

Sounds like whoever whore flashed the radio may have forgotten to realign the radio.

It's probably in serious need of realignment

[Elroy Jetson]

Like I said...the Astro Saber is recently and correctly realigned. I verified it myself, using the combined resources of the radio shop I work for and
my own calibrated test equipment as well. However, ASTRO mode alignments are a bit tougher. I don't have any Astro-specific test equipment.

But I have to get the correct manual for the M/A-Com 7100ip in order to be sure about the exact alignment procedure for THAT radio.

[oktagon]

I would also check the tx allignment of M/A-Com 7100ip. Moto has really good selectivity, so even if the syglas is slightly off it might get filtered out.
Have you tried using another IMBE radio to recieve the sygnal from 7100? I think the problem is not with Moto.

[Elroy Jetson]

As a matter of fact, today I was able to use both radios to monitor Lake County Sheriff's Department, (FL) which is running P25 CAI on VHF.

Both radios received them just fine. Which singles out the tx alignment of the 7100 as the problem.

Incidentally, the recovered audio from the SIGNIFICANTLY older Astro Saber (about ten years older!) is far superior.

Elroy

[d119]

FYI Elroy, latest HOST for Astro Saber / XTS is R07.71.00, so you're not exactly up to the minute, as you pointed out. Your DSP is current however.