[Hallicrafters] rotor-mast

[Roger K8RI]

You might do better with this subject on the TowerTalk reflector, but for my 
2 cents worth.
My system is a bit larger than many  ( 
http://www.rogerhalstead.com/ham_files/tower.htm ) and along with the 
roughly 44 feet of masting is pretty massive as well. I went through several 
HDR 300s, and had to stick a Tail Twister or Ham IV (I've forgotten which 
now) in there to hold things steady until the new rotator arrived. I found 
that is not a good brake arrangement for a massive system when the wind is 
blowing if you try to turn the antennas  Same goes for the HDR 300. <:-))

You didn't say how large the 7L yagi is, or how much masting you have.

1 1/2" Galvanized pipe is very easy to drill through, but were it me (and 
it's not) I'd not pin a large antenna and mast to the Ham ** series 
rotators. It's cheaper to let them slip a little. If there's any play in the 
system a big antenna can tear the rotator housing apart.

Although the idea behind the sand paper sounds good, in reality the sand 
paper will act more like a bunch of little bearings. A thin piece of 
rubber/innertube *might* work. It'd hold better but at some point will slip 
like a clutch. One local ham uses something like that on some very large 
antenna array to rotator connections.

As I recall the Ham IV has a "set screw", or bolt you can tighten into the 
mast.  If you tighten the clamp properly and then tighten this set screw you 
are close to the design limits of the rotator.

OTOH there will be people who have put very large antennas on relatively 
small rotators and used them successfully for years.  I went through over 
$3,000 worth of rotators in as many weeks.  The HDR 300s, the Ham IV (or 
tail twister) and finally installed a PrositTel PST61 which costs twice as 
much today as it did then.
The PST61 is still working.


Anyone have a suggestion as to how I can secure the mast going up to my 7 
element beam more securely to my ham IV rotor. I know that someone ( I can't 
afford it) sells a device for this purpose but thought I could use
something else, like rough sandpaper, to increase the friction between the 
mast and the rotor.

I also could use a portable drill and drill through the top of the rotor and 
then through the mast but the mast is
1 1/2" galv. pipe and the going would be tough.

Any suggestions?

73 Jack
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