Vertical section is now 15 meters but only 31 radials connected at the moment. Note the 80m trap on the horizontal section that allows to use the antenna on both 80 m and 160 m. The shunt coil at the feed point brings the impedance close to 50 ohms.

Some photos from the project.

Sections of Rohn-55g on the ground.

Bearing installation on the tower (left to right: Dale, K5ZXH; Matt, KC1XX; Jussi, AA6KJ).

Theodore inspecting the foundation and the rotor

The first piece of Rohn-55g on the rotor

All 140′ of Rohn-55g up!

Antennas going up!

All done!

I worked 15m single band (high power, unassisted); about 30 hours. Some issues during the contest:

• 5 hour power outage on Sunday morning. Of course, there was a great EU opening during that time! G E N E R A T O R next time…
• hamlib/rigctld keying problems that required frequent restarting of both not1mm and rigctld. Switching to cwdaemon for the next contest.
• It was cold in the shack! I need to work on the insulation!

But still the contest went much better than last year (… new antennas …): 1344 QSOs, 122 countries, and 35 zones.

The following software works great (on Arch Linux):

• General logging: qlog which can be found from both AUR and Flatpak
• Digital modes: WSJT-X_improved from AUR
• Contesting: not1mm. I recommend using cwdaemon for generating CW rather than CAT with rigctld. The latter is buggy and can crash frequently. Install using the uv system (python).

145′ Rotating Rohn 55 tower (tower hardware & installation KC1XX) 

Antennas:

• 160m/80m inverted L with 80 radials
• 60m dipole
• 40m 3 element yagi (JK Antennas) at 145′
• 30m 2 element yagi (JK Antennas) at 105′
• 20m 3/3 yagi stack (JK Antennas) at 132′ and 90′
• 17m 3 element yagi (JK Antennas) at 105′
• 15m 4/4 yagi stack (JK Antennas) at 132′ and 90′
• 12m 4 element yagi (JK Antennas) at 105′
• 10m 5/5 yagi stack (JK Antennas) at 132′ and 90′
• 6m 6 element LFA yagi (InnovAntennas) at 52′
• Antenna switching: Hamation Bandmaster V controller
  and DX Engineering RR8B-HP remote switch
• Stack match: Hamation PB-2 controller and Hamation
  SM-2 switching unit
• Rotor: K0XG rotor and bearings from KC1XX
  and Green Heron RT-21 controller
• UNUNs & BALUNS from Balun Designs
• LMR-600 UltraFlex and 7/8″ Heliax coaxial cables from Davis RF

Elecraft K4 with KPA-1500 & Acom 2000A amplifiers.

If one starts cwdaemon directly on Linux, it produces rather choppy and poor CW. So, I experimented a bit and it seems that the following will produce nice and consistent CW:

# echo 1 > /sys/bus/usb-serial/devices/ttyUSB1/latency_timer
# chrt -f 99 /usr/bin/cwdaemon -d /dev/ttyUSB1 -o key=DTR -o ptt=none -x n

This reduces the rs232 port latency (1st line; 1 ms latency), runs cwdaemon with real time priority (chrt command) and disables audio output on the computer (-x n). In my case above /dev/ttyUSB1 is the RS232 port for the radio, which uses DTR signal for keying.

Once can put the above in a bash script so cwdaemon can be started easily.