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Re: [TowerTalk] Proper torque settings for G-2800 rotator mast clamp bol

To: Grant Saviers <grants2@pacbell.net>, "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Proper torque settings for G-2800 rotator mast clamp bolts?
From: Jim McDonald <jim@n7us.net>
Date: Sun, 25 Dec 2022 15:12:15 +0000
List-post: <mailto:towertalk@contesting.com>
Is anyone using the K7NV mast clamp with the Yaesu G2800?  Any issues?  Can it 
replace the Yaesu brackets without raising the mast to accommodate it?  (I 
understand I'd have to remove the rotor to slide the K7NV clamp up onto the 
mast.)

Thanks!

Jim N7US


-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Grant Saviers
Sent: Saturday, December 24, 2022 18:34
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Proper torque settings for G-2800 rotator mast clamp 
bolts?

I believe from using 3 Yaesu rotators, the 2800 bolt torque limit is more about 
the yield strength of the die cast clamps than the bolt strength.  A torque 
wrench will measure what "1/2 to 1 turn" really means.

The bolt heads will be marked so that will reveal the bolt strength and the 
permitted maximum torque can be looked up.  Since everything yields a bit, it 
is best to tighten in a pattern and repeat it 3 times.  After a day or two is 
even better but that is another tower climb.

Grant KZ1W

On 12/24/2022 11:50, Alan Higbie wrote:
> 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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