Hello All,
There are many key factors if you are shopping for an HF transciever with respect to MARS operations as we are now making use or more frequencies that do not straddle the edges of the Amateurs bands and newer digital modes.
1. The ability for the radio to operate at all frequencies between 2-30Mhz at full output and a clean signal is needed. Full built-in automatic antenna tuner performance if the radio is so equipped is also required. So existing makes/models fall short on this.
2. Transmit/Receive recovery time: This is critical for the use of digitals modes and especially with the use of Automatic Link Establishment (ALE).
3. Wide Bandwidth Selection: The day used to be that a 2.4khz or less SSB bandwidth with the way to go, that being needed for receive capability on our crowded Amateur bands. However, for ALE operation we need a wider bandwidth now, 2.6Khz for 16 tones and 2.8Khz for 39 tone ALE. Thus the addition of a 2.8Khz filter from the likes of INRAD etc. or IF DSP is needed here.
4. A nice feature, would be full radio interfacing
for external TNC's and PC sound card digital solutions where the radio provided all the points of connection and automatic switching between microphone and modems. Some manufacturers have attempted to address this with Accessories ports (ACC) to some
extent, but have fallen short of real success.
Sincerely,
Steve Hajducek, N2CKH/AAR2EY NJ