Plishner Antenna Site Work Trip Report. By Gary Agranat. Photos by Steve Plock.
Ed Corn, Steve Plock, and Gary Agranat traveled to the Plishner antenna site in Haswell this past Saturday, October 19, 2019. The team completed erecting the 50-foot ham radio tower.
Completing the tower erection involved several tasks:
- Installing the 3-band/3-element Yagi HF ham antenna,
- Installing the 2-meter band vertical antenna on top of that mast. This will be our new antenna for our VHF talk-in radio system.
- Installing two stand-off bracketed supports near the top of the tower on the sides, to raise and hold the 80 meter band and 160 meter band dipole wire antennas. This arrangement replaces the long pole that previously centrally supported those wire antennas. These bracket supports each have a pulley and rope, to raise and lower the wire antennas. The tower also supports a 6-meter band delta-loop antenna, which is simply tied from height.
- Securing the coax cables for the Yagi and vertical antennas along the side of the tower.
- Properly arranging the system of wires, coaxes, and support cables.
- Raising the 50-foot tower, which involves turning the winch system that rotates the tower up from its pivot plate at its base. The 50-foot tower is raised from a pulley system on a second smaller adjacent tower.
- Once the 50-foot tower is raised, securing 3 guy cables.
Steve tested the SWR of the 3-band Yagi antenna with an analyzer. The antenna elements had been measured and assembled on a previous trip, to be optimized for the middle of each of the operating bands, of the 10, 15 and 20 meter bands. Steve measured an SWR ratio of 1:1 (perfect) at 28.51 MHz for the 10 meter band, and 1:1 at 21.19 MHz for the 15 meter band. The 20 meter band resonated with an SWR of 1:1.35 at 14.16 MHz. This is excellent, and as expected.
For lunch, Steve treated us with smoked ribs from Broken Bones BBQ in Monument, with sauces, potato salad, and coleslaw. Gary brewed coffee. Also, the team met first at the firehouse in Ellicott. Gary baked orange-cranberry muffins. We ate our muffins at the firehouse, and shared the rest with the fire department crews there.
The team left the Plishner site by 4:30 pm.
The tower work began about a year ago. The work involved support and efforts by a number of team members. See our past posts from October 19-21, 2018 http://dses.science/plishner-site-report-for-the-weekend-of-october-19-21-2018, August 24, 2019 http://dses.science/plishner-work-trip-report-august-24-2019, and September 28, 2019 http://dses.science/work-site-trip-report-at-the-haswell-plishner-radio-telescope-site-september-28-2019.
The tower should significantly improve our capability to communicate long distances on the 10, 15, and 20 meter bands with the Yagi. The 2 meter band vertical should enable us to communicate on our talk-in VHF radio system to much further out.