On 2/8/2011 5:25 AM, pc2a@pi4cc.nl wrote:
> Michael W5NIG schreef:
>>> Does anyone know how much different, if any the newer PST61D is to this
>>> earlier 61 rotator? So far the 61D has been turning the Steppir MonstIR
>>> for
>>> 4 years without a problem.
>>>
>>> 73,
>>> N2TK, Tony
>>>
>>>
>> I'm curious about this as well! I bought a used 61 (motor sits vertical
>> instead of horizontal) last year, think it is abt 10 yrs old. (was on pins
>> and needles
>> until I got home and tested it, hi hi:) Any trouble with the older
>> version
>> I should watch out for?
>> Michael de W5NIG
> We (PI4CC) has bas experience with this rotor. Within 5 years it hits
> the trash can.
> http://www.pi4cc.nl/bigboy/
I just noticed this link. Very interesting photos. Are you sure that's
not a PST-71? It appears to be larger than my 61. But be that as it
may, IT appears that you must be located near the sea. I've never seen
that much corrosion on a rotator and I've seen some bad ones.
Even had you removed the bearings, this would have involved some major
restoration work including the housing and motor.
It certainly would have benefited from several coats of good paint. I
use an *Industrial* *Alkyd Enamel. Specifically I use DEVOE Devguard
4308 Machine Gray (4308-6110). I have no interest in the company or
sale of their products, but having worked in the chemical industry for
over 32 years I was exposed to a lot of these paints. I was exposed to a
lot of other stuff too<:-(( Fortunately I was lucky.
At any rate this paint and a self etching primer can be brushed or
sprayed on. The can says "needs no thinning", but I thin it about 25%
for a conventional paint gun running about 45 psi. No thinning would
probably work in an HVLP gun, make less mess, and save a lot of paint
plus it gives a very durable finish. I'd prefer a powder coat baked on
in your environment, but that's not very practical and that poorly
designed top seal pretty well finished it off.
I was surprised to see corrosion, let alone that amount in the bottom
cavity where the direction pot is located.
Yes, you would have had some serious work to rebuild that one including
a thorough sand blasting and complete repainting of the exterior.
BTW I have the motor mounted horizontally on mine. I had to do that to
get it to fit into the 45G. I've seen them installed with a weather
proof but well ventilated box enclosing the motor. The corrosion in the
top of the motor was a real eye opener. I've never seen the fan cover
corroded with only the fan left in tact. To see one nearly disintegrated
is really something.
Although I like the new versions of the rotator and they do make a mil
spec rotator (for a price), I think my next one would be an Alpha Spid.
I've shown this photo many times but this is what I was turning with my
PST-61 http://www.rogerhalstead.com/ham_files/Tower29.htm. The rotator
handled the load just fine, but the leverage of that tall mast and those
antennas destroyed two TB-3 thrust bearings. When weather permits and I
can find all the parts under the snow, I have a 40M3-125 going up at
100' with the 7L 6-meter yagi at roughly 112'. I don't know how long it
will last, but I've had several requests to put the 21' tall diamond
144/440 antenna on top of the mast. That will put the base of the
vertical at roughly 120' for packet and other digital modes.
I have all of those antennas down at the moment for maintenance and the
current weather is not exactly ideal for antenna work with temps below
zero at night and 12 to 14F in the day (-18C to -11C). BUT it looks
like a warm up this week end. It'll be about the first time we've been
above freezing for a high since before December and "they" are
forecasting Sunday to make 40F or 4C (If I did the math correctly).
ALTHOUGH they are now starting to lower the forecast a degree or two.
It's been too darn cold and windy (with lots of snow, but nothing like
when I was growing up on the farm) to even work out there to mount a
mast holding the AV-640 vertical on the NW guy anchor post. The snow is
about 2 1/2 feet or about 76 cm deep at that point. However if it makes
it to the forecast temps from Sun through Thru we shouldn't have a lot
of the stuff left...I hope. OTOH under all that snow the ground isn't
frozen. We can have a solid foot of frost in the ground. Put a foot of
snow on top of that and the ground will be thawed within a week.
73 and better luck with the next rotator,
Roger (K8RI)
> Peter
> PC2A
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