[MRCG] band conditions Saturday night

[Mark J. Blair]

> On Nov 29, 2015, at 17:07, epvgk at limpoc.com wrote:
> I'm copying your opening message more or less with ST-6. 
> Transmitting is problematic as the high tone is outside the
> transmit bandwidth of my ic7000, so I need to figure out 
> some clever split setup to keep feeding the ST-6 high audio
> tones while letting the radio transmit/receive 1000 hz lower.
> Anyway I have no idea if I'll hear anyone else but I'll
> leave the machine on and printing anyway. 

I cheat by setting my modern rig 500 Hz higher to center the tones in its passband. We picked the tones for compatibility with the PRC-47 and its matched FSK modem, since it's the least frequency agile rig we expected to be used on the Clatternet.

For a numerical example, I presently have the radio set at 3587.5 KHz, and my center freq. at 1500 Hz in fldigi. A PRC-47 would be set to 3587.0, but it's modem's center frequency is at 2000 Hz so the actual mark and space frequencies come out in the same places on the air. We call the channel "3587" as that is the tuned frequency on a PRC-47 (maybe on a GRC-122/142 also?), but actual mark and space tones are higher due to the AFSK modems. Things get most difficult for true FSK rigs like the GRC-46, since they need to set transmitter carrier frequency right on one of the tones, but they also tend to have touchy tuning. It's all a compromise to maximize the number of different green rigs that can play.

Anyway, I had pretty good comms with AG6EB from San Fransisco here in Riverside, and noisy comms with K6NE from Ventura.

Heard a weak station a couple of minutes ago, but zero copy.


-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/