Using EMP-Hardened HF Ham Radio to Send/Receive E-Mail During Nationwide Outage- Part 2, by PrepperDoc
Transmit-Receive Frequency Offset This should be zero. Synthesized digital radios have no problem accomplishing this; however, vacuum tube rigs may struggle. Surprisingly, the less expensive HW-series transceivers and the SB’s with the vacuum tube based LMO (VFO), in my experience, have little shift between transmit and receive. Later SB-series transceivers with the solid-state VFO may have an offset. If this offset is > 100 Hz, you’ll notice it during SSB conversations (“leapfrogging” as you chase the fellow you’re talking to), and you’ll want to fix that for digital communications. Happily, the solid state LMO includes a FSK (frequency shift keying) …