[TowerTalk] Tower project

[Gene Fuller]

Hi Doug -

Your twin towers sounded a bit familiar. Digging back in my "swamp"  I came up with a two page "Collins "Product Description and Application" from the mid 1960's which describes their Model 237B-4 Rotatable  Unidirectional HF Antenna (Collins part number 522-1536-025).This includes two 80 foot towers, four guy cables, a 90 foot mast with split bearing at the top and motor, gear reducer and rotary joint  at the base, and a 6.5-30 "Megacycle" LP - 12 full sized elements (longest is 80 feet) on a 61 foot boom. Antenna is hinged on the mast and mast hinged at the rotator at the base of the tower. All designed for 120 mph wind or 80 mph with 1/4" on ice. 

I was working for General Dynamic / Electronics Division here in Rochester (NY) at the time and was Project Engineer for the HF communications system antennas for the Apollo mission tracking ships which required several 7-30 MHz LP's, so I interviewed and collected data from a number of sources. I also found a spec sheet from Antenna Products Corp, much less detail of interest except that they also offered both 6.5-30 LP and a 4-30 MHz LP with a 116 foot boom and longest element of 123 feet, also with twin 80 foot towers. We purchased the antennas from a relatively small company down near Boston (CHU Associates) who did a really nice job of design and manufacture of those and some for another requirement. I did also talk with and get a quote from Hy-gain but didn't see any info on their twin tower setup. 

Sorry I don't have any specific tower installation instructions, but with the model and part number you might be able to dig something up. It sure looks like you should have a real good tower if you can figure out how to safely erect it. Collins did offer a winch type erection kit for the mast and antenna but that was only for after the tower was in place.

Good luck with the project !

73's,   Gene / W2LU