Batboard

Hello group, I have a VHF M1225. I want to use the radio in the two meter amateur radio band, down to 146 MHz. I am able to program the radio down there. The receiver has good sensitivity but power output is lacking. I am getting about three and a half watts out in the 146 range. Without changing anything other than the transmit frequency to 154 MHz I get 40 watts out. Is there some known transmit tuning or tweaking I need to do? I don’t have a service manual. Help would be appreciated!!! Mick – W7CAT

TARRA_Mick wrote:Hello group, I have a VHF M1225. I want to use the radio in the two meter amateur radio band, down to 146 MHz. I am able to program the radio down there. The receiver has good sensitivity but power output is lacking. I am getting about three and a half watts out in the 146 range. Without changing anything other than the transmit frequency to 154 MHz I get 40 watts out. Is there some known transmit tuning or tweaking I need to do? I don’t have a service manual. Help would be appreciated!!! Mick – W7CAT

Not having moved that specific radio myself, my bet would be on the PA output filter needing more L or more C.

Jim

What he's saying is you should have the radio retuned for where you want the max RF output. Best to do it with good equipment because on all these radios there's more to the setup than just tweaking the final amplifier's output (though you MAY be able to get away with a simple final tweak). I have one of these units running on UHF and it seems to work fine but your inquiry prompts me to check my radio with a Bird meter next chance I get to see how it compares between, say, 460 and 446 mHz on transmit.

Regards,

Just for reference, I am using a HP service monitor to look at everything. I feel like I am okay for test equioment to work on it with. I just got a UHF M1225 and don't seem to find any trouble done at 445. It still has about the same power and sensitvity. As a side note, I am using the VHF and UHF along with two IDer's to build a true crossband repeater that will go either direction and be legal. It will be installed for mobile operation. Mick - W7CAT

Our Club has received a donation of some of these M1225. I am seeing the same issue, low RF when programed for the amateur freqs.
Has anyone resolved this without the need of service monitor ? Detailed procedures, can they be found anywhere ?
Pete -N1ZRL