Seacom SEA 245 HF Transceiver
SEA 245 Notes
- Program Scan - Select frequency, mode, etc. [Radio], 7, bin number,
[enter], 1 (overwrite existing bin), [enter], alphanumeric name (default is
userfreq), [enter], 1 (scanning mode voice), [enter]. If first three characters
of name is different from that of the previous bin, this is the start of a new
- Scan Mode - Determines whether a scan leaves an active channel after the
hang period or, instead, stays on the channel until it is inactive.
Continuous (stay on active channel) - [Radio], 1,3,1
Stop and Go - [Radio], 1, 3, 2
- Start Scan - Select a bin number in a scan group by keying in bin number
followed by [enter] (such as 1, [enter]). Key in [Radio], 8 to start scan. PTT
stops a scan.
- Current Scan
- 1 - 7.086 MHz LSB, RTTY
- 2 - 7.200 MHz LSB, Voice
- 3 - 14.086 MHz LSB, RTTY
- 4 - 14.200 MHz USB, Voice
SEA 245 Documentation
Seacom SEA 245. This runs 150W CW or SSB between 1.6 MHz and 30 MHz. It is a dual conversion system with the first IF at 45 MHz and the second at 40 kHz.
The 40 kHz IF is run through an A/D and then into a DSP where final filtering and demodulation are handled in a DSP. On the transmit side, the DSP generates the SSB (or other) signal at 40 kHz. It is then
upconverted to 45 MHz, and then to the final transmit frequency. The high first IF provides good image rejection with broad band RF filters. In fact, the same band pass filters that are used on the
transmit side are used on the receive side.