At 08:05 AM 07/19/09, you wrote: >Okay guys, I might be biting off more than I know here, but I've been >tasked out to try to get this accomplished for a new fledgling group >of hams here. >How much effort is really involved in converting a 406-420Mhz Mastr II >machine (combination ending in 77) up to the ham band? > >Need to start learning more somewhere and this seems like a good >avenue to take. > >I'm sure someone must have written up a step by step guide for >re-tuning, I just have not found it yet. A point in the right >direction would be helpful. > >Thanks, >Dave - N0TRQ
Pulling a 406-420 MHz radio 25 MHz up is darn near impossible. On the other hand pulling a 450-460 radio (that the designers were deliberately a little sloppy on the low end) down 10MHz is rather easy and already well documented. If you really want to proceed, however, the instructions boil down to: 1) RX: Remove the front end and the oscillator multipler chain and totally rebuild with 88 series components. 2) TX: Remove the exciter and rebuild with 88 series components. 3) TX: Remove the PA deck and replace all the ceramics with the ones from a 88 series. The easy way: Post a message saying "Anybody want to trade an 77 series radio for a equivalent 88 series?" The 88 series radios that will pull down a little to 440 are 50 times more common than the 77 series ones that are highly prized for point-to-point links (420-423 MHz range). Mike WA6ILQ
