Why is there a pause between A/B QCII tones when encoding?

hsfdchief200 · Post by **hsfdchief200** » Fri Jun 02, 2006 2:48 pm

We are using CM300s and HT1250s to encode QCII tones. We use the A/B and Long B tone format. There is a slight pause between the A and B tone when encoding with these radios.

None of our other radios (Kenwoods) or the Motorola Moden 100 encoder has this pause between the tones. I've looked all through the programming software and can't find anything about adjusting the time between the tones. Am I missing something, or is this just how these radios operate?

nmfire10 · Post by **nmfire10** » Fri Jun 02, 2006 6:14 pm

My CDM1250, all my kenwoods, and the Centracom Gold all have no delay between tones. I don't know why yours are doing that, it isn't normal.

Al · Post by Al » Fri Jun 02, 2006 8:35 pm

To my knowledge, there's no user-programmable options for dead time between QCII tones. I agree with Matt: on any recent CDM1250 or CM300 I've never noticed any dead time. Things like QCII formatting are handled internally in the firmware, which brings my question to mind: what are the firmware versions in your two mobiles? If the firmware is very old the timing parameters may have been changed in recent firmware revisions to eliminate or minimize the dead time you're seeing between the A and B tones.

hsfdchief200 · Post by **hsfdchief200** » Mon Jun 05, 2006 7:08 am

We have 5 CM300s and 1 HT1250 that all have the very small gap between tones. The firmware on the CM300s is R03.00.03. I assume that it's still causing the pagers to go off - haven't heard any complaints from anyone. However, it just doesn't sound right. I thought at first it might be b/c of our higher tones that we use (from 1122.5 Hz - up). A neighboring dept pages with the same equipment, and they have no gap. Their tones are considerably lower, though, in the 600 Hz range.

Post by **alex** » Mon Jun 05, 2006 9:14 am

Firmware versions? This could be the problem.

You can find the firmware version under the utilites menu in the radio, or by reading the radio, and looking in the general information tab (it should be there...)

-Alex

Al · Post by Al » Mon Jun 05, 2006 12:36 pm

hsfd, just to satisfy my curiousity, I put a QCII system into a CDM1250 that is flashed to the current firmware level, R05.05.17. The tones I used were A=1122.5, B=1687.2, and I noticed no dead time between the tones when the call was sent with the front panel buttons and the PTT switch. I'd be curious to see your CM codeplug because the firmware version you mentioned is *not* that old(should work OK with no dead time).

n5tbu · Post by **n5tbu** » Thu Jun 15, 2006 3:31 am

I am not a two tone expert,and it has been awhile......
There were quite a few standards out there,GE,Motorola,Plectron,etc.
I think it was the Plectron and maybe the GE tones where a pause between tones was required for it to alert you.
For a more detailed description of the different tone schemes,Google a zetron encoder manual.
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