Folks,
I'm having an odd problem with my AS 3. Everything seems to work fine except transmission of IMBE signals. I can successfully decode IMBE signals such as LAPD, HT-to-HT or a couple of ham-band repeaters using Quantars here. However, transmission HT-to-HT or to the 2 local repeaters is a different story.
To decode signals, I select the normal C4FM modulation scheme. Everything works fine. But to be heard, I have to program the channel as WIDE, not C4FM. I then cannot decode the same radios which now hear me.
Is this due to a HOST/DSP mismatch? Is something else afoot here? Programming error on my part, perhaps? I'm rather curious. My radio's data is below:
ASTRO Saber III UHF 403-470Mc
Model: H04RDH9PW7AN
FLASHcode: 591008-4F1E00-9
HOST Revision: R07.11.00
DSP Revision: N08.02.06
This is supposed to be a more recent radio. Obviously a parts radio. (No tags, etc) But in good condition & working well otherwise. If I can fix this problem, I'll be 100% satisfied!
-KGB
ASTRO Saber III - Digital TX Issues?
Moderator: Queue Moderator
Yep, that's an official Nick radio. It needs to be aligned by someone who understands ASTRO and knows how to align these radios. They're not like analog gear - close doesn't cut it.
I can align analog gear all day long. I lack a P25 service monitor, so I send my P25 alignments out to someone with appropriate equipment and good qualifications.
I can align analog gear all day long. I lack a P25 service monitor, so I send my P25 alignments out to someone with appropriate equipment and good qualifications.
Mystery Solved? (Let's hope)
Thanks for the feedback, fellas. I was hoping it would be something simpler than firmware/DSP issues. Being new to owning ASTRO equipment, I'm still in part of the intial learning curve.
While it's not a P25-capable monitor, I tried re-aligning the radio a few minutes ago with ASTRO Portable CPS Tuner using my IFR 1200S to monitor waveform & deviation. The values were *way* off in the tuner screens. Doing what I could, I adjusted them per the brief instructions in help. Perhaps this'll do it. If not, I can have a friend with a P25-capable monitor do a "true-blue alignment".
The CPS instructions said "align for ~2.83KHz" in the 'Deviation Limit' screen & a Deviation Match in the 'Deviation Compensation' screen. Just for kicks, here are my before & after tuning values:
Original Values,
Mod Comp Balance:
403.1 @ 56
424.85 @ 59
438.05 @ 58
444.05 @ 57
456.35 @ 57
463.7 @ 56
469.65 @ 56
New Values,
Mod Comp Balance:
403.1 @ 49
424.85 @ 48
438.05 @ 48
444.05 @ 48
456.35 @ 46
463.7 @ 45
469.65 @ 45
Deviation Limit,
Original Values:
403.1 @ 102
424.85 @ 106
438.05 @ 105
444.05 @ 103
456.35 @ 104
463.7 @ 102
469.65 @ 100
Deviation Limit,
New Values:
403.1 @ 60
424.85 @ 55
438.05 @ 58
444.05 @ 57
456.35 @ 55
463.7 @ 54
469.65 @ 55
Thanks again for your input. This is something I should've thought of & didn't, but am not surprised to find it being the case. (Misalignment)
-KGB
While it's not a P25-capable monitor, I tried re-aligning the radio a few minutes ago with ASTRO Portable CPS Tuner using my IFR 1200S to monitor waveform & deviation. The values were *way* off in the tuner screens. Doing what I could, I adjusted them per the brief instructions in help. Perhaps this'll do it. If not, I can have a friend with a P25-capable monitor do a "true-blue alignment".
The CPS instructions said "align for ~2.83KHz" in the 'Deviation Limit' screen & a Deviation Match in the 'Deviation Compensation' screen. Just for kicks, here are my before & after tuning values:
Original Values,
Mod Comp Balance:
403.1 @ 56
424.85 @ 59
438.05 @ 58
444.05 @ 57
456.35 @ 57
463.7 @ 56
469.65 @ 56
New Values,
Mod Comp Balance:
403.1 @ 49
424.85 @ 48
438.05 @ 48
444.05 @ 48
456.35 @ 46
463.7 @ 45
469.65 @ 45
Deviation Limit,
Original Values:
403.1 @ 102
424.85 @ 106
438.05 @ 105
444.05 @ 103
456.35 @ 104
463.7 @ 102
469.65 @ 100
Deviation Limit,
New Values:
403.1 @ 60
424.85 @ 55
438.05 @ 58
444.05 @ 57
456.35 @ 55
463.7 @ 54
469.65 @ 55
Thanks again for your input. This is something I should've thought of & didn't, but am not surprised to find it being the case. (Misalignment)
-KGB
You don't need a P25 monitor to align these radios - although a BER or modulation fidelity test on a P25 monitor will tell you how good a job you did.
What you do need is a accurate monitor AND you have to be careful that the monitor's default settings [or your favorite settings] for IF bandwidth and rx filters don't introduce error.
The important alignment of the modulation balance uses two tones - a low tone and a high tone [which is 3000 Hz]. In the analog world we set deviation at 1000 Hz - never at 3000 Hz. If your monitor settings cause it to roll off the audio at 3000 Hz ahead of the deviation metering - you will align your radio wrong - and cause it to be unable to transmit to other P25 radios.
What you do need is a accurate monitor AND you have to be careful that the monitor's default settings [or your favorite settings] for IF bandwidth and rx filters don't introduce error.
The important alignment of the modulation balance uses two tones - a low tone and a high tone [which is 3000 Hz]. In the analog world we set deviation at 1000 Hz - never at 3000 Hz. If your monitor settings cause it to roll off the audio at 3000 Hz ahead of the deviation metering - you will align your radio wrong - and cause it to be unable to transmit to other P25 radios.