[TowerTalk] PST61 Rotor Reliability?
rob at n1kez.net
Fri Dec 15 10:44:19 EST 2017
I have the PST-71D with GH controller. Optibeam 12-6 at 65Ft on the tower. Tower is on the crest of a 650ft ridge where the winds occasionally can be gnarly. No problems identified so far.
73 & gud DX
Rob de N1KEZ
Sent from my mobile device.
Please excuse brevity and errorz.
> On Dec 14, 2017, at 10:26 AM, Jim Thomson <jim.thom at telus.net> wrote:
> Date: Wed, 13 Dec 2017 12:37:52 -0700
> From: David Gilbert <xdavid at cis-broadband.com>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] PST61 Rotor Reliability?
> <THANK YOU!
> <Finally someone understands.? I never meant my original reply about the
> PST-61D to devolve into this lengthy discussion, but I couldn't let it
> drop without the story being set straight.? My situation is indeed
> peculiar ... possibly even unique ... but some physically erroneous
> comments were popping up in some of the replies that needed to be corrected.
> And yes, my options at this point appear to be either a PST-71D or a
> prop pitch from K7NV.? I've ruled out the PST-110D for two reasons ...
> one is simply the weight of the beast, and the other is the fact that
> Pro-Sis-Tel apparently went to a Hall Effect position sensor for it.?
> Here is WA7NB's experience with the PST-110D:
> He ended up going with a prop pitch (don't remember which size).? I
> emailed Array Solutions to get their side of the story on WA7NB's
> issues, but they never responded.
> 73 and thanks again,
> Dave? AB7E
> ## The small K7NV PP I have.. + its mating GH control box is dead
> simple, point and shoot affair, with ramp up and ramp down features, etc.
> ## GH took a standard RT-21 control box, and modified it for the
> small PP. It contains a single hammond xfmr and rectifier for the PP motor,
> aprx 32 vdc un regulated, and with no load. Vdc drops of course, with the normal
> 10A load on it. The small PP weighs LESS than my M2 OR-2800 and eats it for lunch
> hands down. The small PP has a stupid amount of tq, like > 1200 ft lbs. Beauty
> is, it hangs BELOW the rotor plate..and is bolted to the rotor plate with just 6 x
> .375 bolts. The mast clamp is the ultimate, BUT they have to be configured for
> an exact size OD. Mine is setup for my 2 inch OD x .375 wall thick 4130 CM
> mast. He will make the mast clamp for any diam you want, like 1.9 OD up to
> 3.0 inch OD, or even bigger. The mast barely slides in. Once the 6 x mast clamp
> bolts are tqed down, the mast will not slip. Heck, I tested it with just a pair of vice grips and
> a rag to protect the finish..and no bolts at all. You barely pinch the mast clamp,
> and it clamps 360 degs around x aprx 6 inchs tall. IE: 2 inch od mast has a 6.28 inch
> circumference. And 6 inchs tall x 6.28 = 36 inches of actual surface area.
> ## with a 2.5 inch OD mast or a 3.0 OD mast, the surface area is even greater.
> And any of the above is far better than the semi useless mast clamps used on my
> OR-2800..and most other commercially made rotors.
> ## Ok, MAX rpm on the small PP is aprx .55 RPM. It takes 1 min + 50 secs
> to rotate 360 degs. with the ramp up and down feature, it will turn a lot slower
> than that. You can also set any speed you want, or START the ramp up speed at
> any speed you want. I bought a small PP back in 1977, it was the same .55 RPM.
> ## K7NV has modified the back end of the electric motor shaft, and installed an
> arm with a magnet on it, plus a counterweight at the opposite end of the same arm.
> This rotating magnet whizzes past a fixed magnet, to produce the pulses..... which are routed
> to the GH box...which is programmed for the 9600 : 1 ratio. GH box can be programmed for
> any ratio you want.
> ## So u end up with superb digital readout down to .1 deg increments. It doesnt get any
> better than this. Lightweight, globs of tq, and ultimate mast clamp. Plug + play. You just
> require 6 x .375 holes in the rotor plate, all spaced every 60 degs. Rotor is brought up from below,
> and bolted to rotor plate. Mast clamp assy simply passes through the large diam hole in the rotor plate.
> Plenty of info and pix on his website.
> Jim VE7RF
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