Batboard

Ran into a reproducible symptom with several of these monitors we have.

Wondering if others have experienced the same issue.

When in GENERATE mode, and running the 1011 test pattern for say a
GTR8000 receiver BER test. The level will be adjusted for an approx 5%
BER figure.

Letting it just sit there idle, the value will suddenly begin to creep up.
To say 7%, 12%, 22% - then back down to 3% and resettle at the original
approx 5% value.

After about a minute or two, it'll repeat the same cycle.

It's definitely caused by the 2670. When we used our other Aeroflex 3920,
the BER figure was rock solid.

Seems like the 2670's have some kind of design flaw if I didn't know
better.

If anyone has time, try the 1011 pattern and measure using the BER
screen in CPS. Curious if other people observe the same symptoms.

Interesting. Can you perhaps feed the 2670 into the 3920, and see if the RF level is wandering or it the constellation/eye diagram gives any clues?

Just curious, how OLD is the firmware in your 2670's? That was a problem before I retired and it was resolved.

DJP126 wrote:Just curious, how OLD is the firmware in your 2670's? That was a problem before I retired and it was resolved.

Dave, I show -

STANDARD V6.12.I00 (that's the letter "i" in upper case before the two zero's).
P25/Astro/SNET V6.11.H00

I presume CTDI loaded the latest firmware when they go in each year for calibration. Do
these versions seem later than the release you had mentioned ?


Wowbagger, the actual RF level and BER going into:
(a). the 3920,
(b). an Anristu S412D w/the P25 option,

appeared to be "normal". Constellation appeared "normal" as well.

Only when running Moto CPS and monitoring BER did the symptoms appear.

"...and running the 1011 test pattern for say a GTR8000 receiver BER test. ..."

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Have you tried the same BER test with any other Motorola products such as Quantar or subscriber products such as APX?