Towertalk
[Top] [All Lists]

Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?

 To: K4SAV Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section? W4LDE-Ron Thu, 20 Mar 2008 09:24:19 -0400 mailto:towertalk@contesting.com>
 ```To add to this thread, how can one ever turn a US Tower rotating tower using the K-factor method since the weight of the rotating tower is roughly 660#'s plus or minus the base assembly weight. Should the tower itself since its similar to a mast be included in the calculations? Thus a US Tower MARB-550 add a 55# antenna and turning radius 19' of would equal a K-factor of 13,400 Not to many rotors capable of that figure, however, I believe the tower does have a load bearing assembly thus removing the weight factor? How much I am not sure and what effect the rotational torque of the tower itself has is unknown to me. Thus that type of tower/antenna by the K-factor would be 19*55 = 1045 plus the effect of torque and any transfered weight.. I am thinking of using a MARB-550 at 55 ft with a SteppIR plus the 40/30 add on but am confused as to how big a rotor is needed? Would appreciate hearing from MARB-550 Owners and there experiences. Ron, W4LDE K4SAV wrote: > I just pulled the info from the web for that calculation which didn't > mention mast weight. I went back to the Yaesu manual, and yes that is > what it says, it includes the mast weight in the calculation. But that > really doesn't make sense. A mast contributes an insignificant amount > of torque compared to the weight of an antenna, and they are counting > them the same. (Antenna turning radius times mast plus antenna weight > doesn't make a lot of sense to me.) So obviously the K factor is not a > guideline for the amount of torque allowed, but must be some kind of > general really rough swag at trying to sum up the total of what is above > the rotator. I'm not sure that is a good way to sum up the requirement. > > Jerry, K4SAV > > John Elsik wrote: > > >> >From the Yaesu manual >> K = turning radius x (antenna + mast weight) >> The mast weighs around 110lbs >> So add 55 lbs to each antenna calculation. Then sum the two >> They give a pretty lengthy example of this in the manual. Metric of course, >> but the result is the same. >> John >> Wa5zup >> >> -----Original Message----- >> From: towertalk-bounces@contesting.com >> [mailto:towertalk-bounces@contesting.com] On Behalf Of K4SAV >> Sent: Wednesday, March 19, 2008 5:03 PM >> To: towertalk@contesting.com >> Subject: Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section? >> >> Are you sure you didn't get a metric number mixed in with the English >> numbers? Using Yaesu's method of figuring the K factor, I get 3264 >> ft-lbs for the antennas you have. The G-2800DXA is rated for 6870 >> ft-lbs. You are at 47% of the rating. >> >> Jerry, K4SAV >> >> John Elsik wrote: >> >> >> >> >>> I have a new LM354HDSP crankup tower. I got the tower up, back in late >>> >>> >>> >> November. That is where the project stopped for the winter. All it is >> holding up is an inv vee for 80 mtrs right now. >> >> >> >>> The antennas are a 4el SteppIR and a Cushcraft XM240 on a chrome moly mast. >>> >>> >>> >> Nothing is installed yet. >> >> >> >>> I purchased a Yeasu 2800DXA rotor to turn it, but now having second >>> >>> >>> >> thoughts if the rotor will handle it long term. The "K" factor is 85% of the >> published rotor rating. >> >> >> >>> I called Yeasu and they told me to take the weight off the rotor. They >>> >>> >>> >> suggested adding a second plate and bearing between the rotor and tower top >> bearing, and take the weight off. Sure did not come away with a warm and >> fuzzy feeling that the rotor would handle the load. >> >> >> >>> So I am taking pause and sort of rotor shopping. I realize I would take a >>> >>> >>> >> hit selling the Yeasu. I would rather be safe than sorry later. >> >> >> >>> I was looking at the M2 Orion 2800 (rotor only) and a Green Heron >>> >>> >>> >> controller. >> >> >> >>> Will the Orion fit in a LM354HD top section? I called Tashjian and they >>> >>> >>> >> could not answer that. >> >> >> >>> John >>> wa5zup >>> _______________________________________________ >>> >>> >>> >>> >>> >>> >>> > > _______________________________________________ > > > > _______________________________________________ > TowerTalk mailing list > TowerTalk@contesting.com > http://lists.contesting.com/mailman/listinfo/towertalk > > _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, John Elsik Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, K4SAV Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, John Elsik Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, K4SAV Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, wa5zup Re: [TowerTalk] Does a M2 Orion 2800 fit in a LM354HD top section?, W4LDE-Ron <=