[SFDXA] K4FK antennas repaired, multiple digital modes available

[Kai]

*K4FK is full operational on all HF bands except 60 m, and in all digital modes: 
PSK, JT65, RTTY, SSTV. *

Today I  repaired the 160 m dipole / 80 m dipole pair. The NE support rope for 
that 160 m band dipole had snapped putting both 160 and 80 m out of commission. 
I found new rope in the shack and made the repair. Both 160 m and 80 m are fully 
functional, and load up with the AL-82 without issues to at least 1 kW.

On the the new computer (W9IL donation) I configured the internal computer sound 
card as the Windows default sound card. That way, all Windows OS sounds stay in 
Windows and do not go out over the air. I then configured each digi program 
(Digipan/PSK, MMTTY/RTTY, and JT65) to use the Signalink-USB  "USB audio codec" 
sound card.

  Digipan, JT65 were simple, but MMTTY was the usual nightmare piece of 
software. The earlier version of MMTTY.exe on the computer did not have a 
"soundcard" setup tab (how can you NOT have a way to select a sound card??), so 
I replaced it with my later version 1.66g. The directories were still all fouled 
up, I was getting all sorts of "missing file" messages from MMTTY because of an 
SSTV installation. I straighten those out as well. All things considered, the 
antenna repair was the easy one!  The MMTTY, Digipan and JT65 programs all work 
fine stand-alone, but I could not figure out that SSTV program, so I left that 
alone. *
NOTE:  All digital modes are configured to operate with the radio in upper SSB 
no matter what band you are on 160m to 6m.*

I also started playing with MMTTY (with Digipan also running so I had a nice 
calibrated waterfall display) to explore the radio SSB filter options. It turns 
out that the radio in SSB mode can be configured with a BW as low as 300 Hz, but 
the center on the narrow  filter is around 1500 Hz and can't be moved much. I 
re-set the default RTTY tones to '1830' which places "MARK" tone exactly 2 kHz 
above the dial frequency - good for two reasons: (1) any audio harmonics are out 
of the pass band, (2) easy calculation for the RTTY spot frequency is dial+2kHz. 
If a RTTY station is "spotted" on 14,085 kHz, you tune to exactly 14,083 on the 
radio dial.

The radio filters can be set to cover that range, and set as narrow as 600 Hz- 
use the Digipan waterfall as a guide. Maybe that's enough because finding and 
tuning in RTTY with less BW is difficult, and you can always use the software 
filter in MMTTY to get twin-peak performance once you've tuned the RTTY station in.

*We will build and operating guide very soon. *

73
Kai, KE4PT