ARDF 80M TRANSMITTER FOR CLASSIC, SPRINTS AND FOX-ORING EVENTS
by Andras Paal, HG0HK (SK)
For ARDF Sprint and Fox-oring training sessions and competitions an
automatic 3.5 MHz transmitter has been designed and built according to
the IARU Region1 ARDF Rules
GENERAL
Power supply: built-in Li-Ion accumulator 3.7 V/3400 mAh
Charger: built-in with automatic, supplied from any 5 V DC source
Charging current: 300 mA
Operating temperature range: -10 ... +50 °C
Dimensions: 70 (W) x 50(H) x 110 (D) mm
Weight: 200 g
TRANSMITTER
Carrier frequency: 10 channels (3.51 ... 3.60 MHz)
Mode: A1A (CW)
Output RF power: HI: 1.7 W, LO: 0.5 W
DC current: max 0.8 A (@4V)
Internal loading possibility: 47 pF series with 68 Ohm
Antenna: vertical wire 7m + 2x7m counterpoises
Fox-oring (Fo): 0.3m vertical wire
Antenna tuner: manual with output power indication
Total hunt time: 6 hours (software limited)
LOGIC UNIT
Transmitted codes: MOE, MOI, MOS, MOH, MO5, MON, MOD, MO and S
Keying speed: 60 or 75 PARIS
Continuous (Fox-oring)
12s transmit, 48s space (Sprint)
60s transmit, 240s space (Classic 1/5 min)
60s transmit, 360s space (Classic 1/7 min)
Time base accuracy: ±10 ppm (1s/day)
Start delay: 0...21 hours, in 3 hours increments.
The modified Montreal Controller allows the PIC to be programmed and then tested without having to remove the PIC16F628A.
I got programming help from Geza Szekely, Jozsef Kujbus, YO5AT and Istvan Vanyi, YO5OFJ.
