KF4RKR Antenna Installation

The AARC Antenna Team completed installation of a 120-foot off-center-fed dipole for Charlie Grisham (KF4RKR). Team leader Ed Berkowitz (N3US) did an initial “virtual” visit via email, with recommendations about how to use a garden hose as an underground conduit for coax leading from a basement ham shack and ideas for where to hang the antenna. The physical situation (a steep second-growth forested slope adjacent to the house) was ideal for use of an arborist’s throw bag (a cloth bag containing 12-14 oz of lead shot) instead of the usual potato cannon (which would have been overkill for this location). John Porter (KK4JP) used a throw bag to put lines over 3 trees suitable for hanging the antenna. Finally, team member Ian Callahan (KN4TBG) and guest installer Patrice Porter (KM4RSL) worked with KF4RKR to successfully hang the antenna. Multiple people were needed for the antenna hanging due to the presence of numerous intervening branches that needed to be maneuvered around using loops of rope as the antenna was raised. Typically two loops of positioning ropes were needed for each leg of the antenna. The final hanging was completed in two hours, allowing time for some tasty sandwiches provided by K4RKR. Masks and social distancing were used at all times, except when eating which was done outdoors with wide spacing between diners.

The team enjoys a socially-distanced outdoor celebratory lunch after a successful antenna hanging. (Photo Charlie Grisham)

Use of the arborist’s throw bag was suggested by Joe Devencentis (KO8V) during one of the informal “Panera” gatherings. The throw bags have an accuracy advantage over slingshots, with comparable range. They have less range than potato cannons, but are faster to use, since a thicker throw line is used, which can directly pull over the final “parachute cord” line, as compared to a potato cannon which uses monofilament line to pull over an intermediate line prior to pulling over the final line. The thicker line on the throw bag may also work better in high winds, where the very light potato cannon lines may drift. But the ideal weather for this installation did not require testing that supposition.

Home-made Arborist’s Throw Bag and Line Container. The Throw Bag hangs from the carbineer between uses. Line is loose within the bucket – it works fine as long as you don’t shake or tip the bucket! (Photo John Porter)