Thanks to Mike (K9MK); John (KK9A); Grant (KZ1W); Jim (N7US); Art (WA2LLN);
Rich (N5ZC); Jon (AA1K); and Greg (K9KL) for all the ideas and potential
solutions.
For the moment I'm not going to pin the mast - because initially when I had
a Yaesu G-1000 - - the mast was pinned - and with a 105 mph wind the mast
did not slip in the clamp. However, the winds ripped the guts out of the
rotator.
That was 6 years ago. Soon after, I replaced the G-1000 with a G-2800 -
despite high winds the rotator-to-mast clamps have held really well. Except
now after another round of 100-105 mph winds that mast has slipped around
approx. 180 degrees.
I'm trading the longevity of the rotator for the periodic inconvenience of
re-orienting the beam. Hopefully, I won't have to do it again for another
6 years.
73, ~ Alan K0AV
On Sat, Dec 24, 2022 at 1:13 PM <k9mk@flash.net> wrote:
> Alan,
>
> I had an original G2800 with a 4-bolt mast cup at my former QTH. It
> held a Mosley Pro-67C3 on it.
> Not a long boom antenna but a sprawling antenna that was heavy. And
> it really flexed around in the winds.
> After a couple seasons a real strong winter wind event spun it.
> Retightening worked for a couple months, and it slipped again in a
> spring storm.
> It was apparent the spline feature in the cups were wearing smooth.
> We decided to pin it to the mast, which worked perfectly for another
> 15+ years.
>
> At my new QTH, I have a couple mid-sized JK antenna. This time a
> G-2800 with the 6-bolt mast cup.
> Yes, after a couple years it slipped too. I pinned it last fall.
> In the past 48 hours we had high sustained winds for hours on end from
> this crazy winter storm.
> No slippage. This solution worked well for me. YMMV.
>
> Mike K9MK
>
>
> -----Original Message-----
> From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Alan
> Higbie
> Sent: Saturday, December 24, 2022 1:51 PM
> To: towertalk@contesting.com
> Subject: [TowerTalk] Proper torque settings for G-2800 rotator mast clamp
> bolts?
>
> As the result of an extremely high wind event, I will soon be going up the
> tower to loosen the G-2800 mast clamps, realign the mast and then
> re-tighten the M8 x 70 bolts.
>
> The Yaesu G-2800 manual says:
>
> “Caution: Do not over-tighten the nuts on the mast clamps.
> They should be tightened until the spring washer becomes flat, then
> tightened further by 1/2 to one turn maximum.”
>
> I am still using the original hardware supplied with the G-2800.
>
> These spring washers have been in service for 5 years - so their
> springy-ness may not be the best indicator for torque.
>
> I believe that torque settings depend upon the grade of hardware being
> used: e.g. 8.8, 9.8, 10.9 or 12.9 - but I don’t know the grade of the stock
> hardware.
>
> What its the proper torque setting for these M8 x 70 bolts?
>
> 73,
>
> ~ Alan Higbie K0AV
>
>
> _______________________________________________
>
>
>
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>
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