Tuesday, September 18, 2007

Laminated Moxon Antenna

Haven't been updating my blog for some time. Not much activities towards my hobbies lately. Too tied up with other commitments...

Anyhow, managed to try fabricating Moxon Antenna for a friend. Unfortunately I forgotten to scale the dimensions to account for the PVC velocity factor of the laminating sheet resulting in very high SWR... Nonetheless, the friend is still able to smile a bit as the Slim-Jim I fabricated for him is giving him much pleasure in his QSO...

The wrong sized UHF (70cm) Laminated Moxon Antenna...

Monday, September 3, 2007

New 144MHz Foxhunt Transmitter

Hello again all,

At the request of several of my amateur radio friends, I've redesigned the previous foxhunt transmitters to make use of a more easily obtain PIC16F84A instead of the PIC12F675. Photo of completed transmitter below. Setting for FoxID and delays are done via jumpers. Overall transmitter power is about 300mW and frequency of 144.010MHz.

For those building the unit, the label below shows how to set the jumpers correctly for various foxes. For sync start, jumper JP2 could be connected in parallel to a single reset switch which can be removed after reset/sync is done.