Fixed TX Power - GM338 UHF

Post by **mvrx** » Thu Oct 13, 2011 12:55 pm

Hi guys,

I have recently purchased 2 x GM338 UHF mobile units (refurbished) and I've noticed something strange. After I set up the TX Power Low and High (Low : 20 / High : 40), I programmed a few channels and measured the power level using a Telewave 44 meter.

To my surprise, no matter the power level I select, the RF Power measured is always ~32 Watts
The level changed slightly when different freq. was used but I couldn't set it to Low TX at 20 Watt or High TX at 40 Watt

I'm using CPS R06.12.02, radio S/N : AZM25RKF9AA5 (GM338 UHF 403-470MHz)

Does anybody have a clue?

Post by **mvrx** » Sun Oct 16, 2011 8:15 am

Problem identified and fixed. You can close / delete this topic.

Thanks for the overwhelming suggestions!

jmr061 · Post by **jmr061** » Sun Oct 16, 2011 9:01 am

It is always nice to state what the problem was so others can learn if they have the same issue.

Jason

Post by **mvrx** » Sun Oct 16, 2011 9:12 am

I totally agree but was surprised by the feedback received. Well, I guess experts are on vacation.

So, in order to fix this "fixed / mismatch" transmit power on a GM300 series mobile, yo will need :

1. Global Tuner R02.16.00 (02.15 is fine too)
2. Watt meter (digital is better for accurate readings)
3. Service Manual for your model / version
4. Read the "Radio Programming and Tuning Procedures -> Transmit Power Tuning -> K and M Tuning" chapter
5. Apply the procedure.

Important : Always backup a copy of your "softpots" (.sfp file) before applying any kind of change!

I hope the above method will save others valuable time.

Regards,
Razvan