[TowerTalk] Hygain vs. Yaesu rotors

[UpTheTower]

From: edward@syr.lmco.com

Date: Thu, 05 Mar 1998 14:07:05 -0500 (EST)
Subject: Hygain vs. Yaesu rotors

With the discussions on the Hygain vs. Yaesu rotors, I thought I'd add my
observations from playing with one of each over the last week.  I brought the
top 2 sections of two towers (towers not yet up) inside this winter so I could
be setting them up with rotors, bearings, and masts.  I was going to use two
thrust bearings on each which requires some care to get everything rotating on
the same axis (rightfully I should not be using two thrust bearings, but a
thrust bearing at the top and a self-centering bearing between the top and
rotor).

One rotor is a T2X I had used for about a year and the other is a new 2800.  I
put a runout gauge on the 2" mast just above the T2X and found the center of
rotation, as defined by the V-block casting, is off from left to right by
almost 1/16"!  No shimming is going to cure a left to right problem.  On top
of that, the V-block axis is not parallel to the axis of rotation!  A friend,
who is a mechanical engineer and has a machine shop, is machining the cast V-
block surface to place its axis in line (left to right and parallel) with the
rotor's rotation axis.  To say he was unimpressed with Hygain's totally cast
design would be an under statement.  When I get the V-block where it is
suppossed to be I'll be able to shim the mast equally against the block to
move it front to back over the center of rotation.

Now this probably seems excessive, and I would never have taken such a close
look at the rotor if I wasn't trying to line it up with two thrust bearings.
With a single bearing there probably is no reason to be so particular.
Although, I wonder if this off center, non-parallel problem in Hygain's
castings is why I broke ring gears in my old Ham IV?

Now the Yaesu has the spilt V-block design.  Since both are movable I can
readily center the mast on the rotor's center of rotation.  If there was a
non-parallel problem I can shim between the V-blocks and the rotor housing.
Now factor in Yaesu's better control box, 450 degree rotation, better cable
connectors, 6 conductor as opposed to 8 conductor cable requirement, quieter
operation, no play when braked, etc. it looks to be a much better unit.  I'll
have to reserve final judgement after I've used it for about two years, but
I'm considering replacing the T2X with maybe a Yaesu 1000, which goes for
about $20 less new.

Brian, N2MF


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