Friday, May 14, 2010

1152 MHz LO Working

Okay, today I finished stuffing the 1152 MHz LO board, which goes with the W1GHZ 1296 MHz "Right Side Up" transverter. Since I hit a few landmines with the 756 MHz board, I double-checked a few things before applying power. All looked good, so on she goes.......

And yes, it's working right out of the chute. As you can see from the photo, I'm only getting -8.58 dBm out of this LO, although my test cable which is about 10 feet long is soaking up about 1 dB.

Paul Wade (W1GHZ) says he got -5 dBm out of his prototype, but that some trimming of the R2 and R3 bias resistors on the last two stages of amplification may be necessary for maximum power output. I'm 2.5 dBm off, but I guess we'll see just how much is really needed when it comes time to connect this to the transverter board, which has another stage of amplification for the LO input.

Next task is to get a 144 MHz IF rig to drive this stuff with. The trick is that these transverters only want to see about 1 mW of drive, so it's going to take some finagling to get the output of any of my rigs down to that level. I'll let you know what I figure out.

73 de W9HQ

No comments:

Post a Comment