Batboard

I wonder if anybody has the original "factory" TX calibration levels for a VHF M1225 for both high and low power. There is basically 8 settings each for high and low power starting at level 0 , 1 , 2 ...7

Full details of my problem is in my "less clear" posting

Thanks

There are no standard factory settings. Each radio has it's own settings. You will need to do a complete
alignment on the radio with a service monitor. Following the manual may or may not provide a clear
step by step guide to it all.

Generally if you have arrived at this point it was caused by the lack of knowledge from a bench tech
playing with the radio and not knowing what they were doing. The other reason is that a major part
of the radio was replaced and as such will need to have an alignment done anyway.

Saving an old codeplug to reload back into the radio will not solve this alignment issue. The alignment
settings are not part of the saved codeplug info.

Jim

g8tzl2004 wrote:I wonder if anybody has the original "factory" TX calibration levels for a VHF M1225 for both high and low power. There is basically 8 settings each for high and low power starting at level 0 , 1 , 2 ...7

Full details of my problem is in my "less clear" posting

Thanks

I guess I am after "typical" TX calibration settings to check to see if the existing settings are way off or more or less in line. They certainly look sensible but maybe the settings follow a "curve" across the band rather than a "straight increasing line".

I will experiment anyway. However, as the M1225 is a fairly "new" broad band radio (my 1st Motorola which uses Windows based RSS , I would have thought that most M1225's just use the original factory settings (unless the PA was replaced or lower power was required - infact it seems a bit pointless to have a 40/25W setting - an extra 2dB will not make much difference in the real world!!

73

To restate, there are *no* typical factory calibrations for the power control loop circuitry.....it varies from unit to unit and depends on whether you're tuning a VHF, UHF, etc. The main point is that if you can't make 25W or 40W at the maximun settings, then there's a problem with the PA, driver, or power control loop. I've seen calibrations run in both a straight line with more or less constant slope and a few with exponential characteristics and "humps" or "dips" in the middle of the curve.
As far as communications coverage is concerned, you're right about 2 dB not making a significant difference, but when you have ERP and licensing requirements to meet in commercial service the 25/40W shift allows compliance.