Warren, KE6LEA and I put together the flex-disc shock absorber
scheme pictured below for the M^2 OR-2800 rotator at W6UE:
Warren got the flex-disc from a local Mercedes dealer. I think
he found that the Mercedes disc is considerably cheaper than
the BMW disc (I think he paid $40). The bottom flange for
the flex disc is the stock Orion flange which we trimmed down
from an ellipse to circle for a better fit in Rohn 25. The top
flange assembly is a home brew job that Warren cut and
welded up from some steel rem that he had laying around his
Some folks probably consider this setup to be overkill, but
the antennas we are turning are a bit on the heavy side for
Rohn 25. The flex-disc arrangement was the cheap
alternative to replacing the existing Rohn 25 tower with
Rohn 45 or 55.
So far so good.
73 de Mike, W4EF.................................
----- Original Message -----
From: "Dennis Mowers" <firstname.lastname@example.org>
Sent: Tuesday, September 10, 2002 6:20 AM
Subject: [Towertalk] Mast Coupler
> Has anyone built the shock absorbing mast coupler described in Leeson's
> "Physical Design of Yagi Antennas"?
> He describes a BMW "flex disc", used to isolate the drive shaft from the
> My local NAPA auto parts supplier shows nothing in their books for any
> year BMW.
> I will try BMW next.
> Has anyone ever seen one of these things?
> Dennis, K5YA
> Self Supporting Towers, Wireless Weather Stations, see web site:
> Call 888-333-9041 to place your order, mention you saw this ad and take an
additional 5 percent off
> any weather station price.
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