Author Topic: VP2 on surplus antenna mast system  (Read 528 times)

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Offline rpegg

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VP2 on surplus antenna mast system
« on: December 31, 2021, 07:50:54 PM »
Last month I got tired of all the trees encroaching the view at my small telescope observatory.  Had a track loader come in for a couple days and clear a large area around it.   The attached photo is prior to the clearing work.   Now it's a great view almost to the horizon for about 200 degrees of compass azimuth.   Some of the darkest night skies on the east coast here in nowhere WV.

So the next project was moving my Davis VP2 off the garage and away from overhanging trees to the new clearing 1000ft away.   Picked up a surplus military winched antenna mast system for free.   The mast system was designed to hold a 75lb antenna at 50ft height in sustained 90mph winds and it's military rugged.   I raised the entire VP2 27ft off the ground  (Could have gone the full 50ft).   It only takes 10 minutes to lower the entire setup for cleaning and maintenance.  I purchased a Davis long range repeater and Yagi antenna to get the VP2 ISS data back to the house.   Had planned to put the repeater halfway between the VP2 ISS and house but as a test I just mounted it above the garage.  Surprised that I'm getting zero data dropouts even though the signal is directly through heavy woods about 1000ft away.   Will see what happens when the tree canopy fills out with leaves in the Spring.    I was in the process of moving an IP camera to the same mast.   Since there is no power out there I had put together a solar panel/battery setup and a couple long range wifi antennas to get video back to the house.   As an Electrical Engineer with a strong electromagnetic theory background I should have immediately known that 2.4GHz and trees don't mix.   Tried to find a 900Mhz setup within my budget.  No luck yet.
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« Last Edit: January 06, 2022, 06:25:59 PM by rpegg »

Offline CW2274

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Re: VP2 on surplus antenna mast system
« Reply #1 on: December 31, 2021, 08:39:57 PM »
I raised the entire VP2 27ft off the ground 
Your temp, dew point/humidity, and rain data will all be skewed.

Offline Bashy

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Re: VP2 on surplus antenna mast system
« Reply #2 on: December 31, 2021, 09:32:44 PM »
I am jealous of that mast and for free, WOW... and ya dome....

As for temps as mentioned already, they wont be 100% accurate to Davis spec) but to be honest, with that ground being what it is, i too would have put it up higher than the recommended height of 4-6ft, probably not the 27ft though (anemometer should be at 33ft(10m)), but certainly a 3rd or even halfway. The anemometer can be separated and this is highly recommended for more accurate temp data and for ease of maintenance but the height placement will depend on the ground cover.

If you can keep green grass around the mast then lowering the temp to recommended height would be ideal, failing that, I believe that artificial grass is used officially here in the UK by our met office at some sites, that's only so they save some money on maintenance at the sites, I feel they will read warmer than real grass but what do I know, spouse it will depend on the quality and grass height. Damn, i cannot believe that mast, I would be looking at around 1000 here in the UK for that used.
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Offline rpegg

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Re: VP2 on surplus antenna mast system
« Reply #3 on: December 31, 2021, 10:34:38 PM »
Thanks.   I can easily add another two 42" sections of mast and adjust the side arm to get the anemometer to 33ft.   Had originally planned to mount the rest of the station lower but it was easier to have it on the same arm during the test and adjusting phase for the mast system and guy wires.   I probably raised and lowered the darn thing a dozen times.   My anemometer wind direction was giving me intermittent data and every time I thought it was fixed it would last several hours and fail again.   Finally gave up and bought a new anemometer.

As far as grass, or grass looking weeds, they will grow back this spring and I'll set everything up correctly.

My nephew is a metal scrapper.   He gets dump truck loads of unwanted equipment from the local military base and scraps it for the metal content.  I picked up 3 of those mast systems still in their original military cases.   Haven't decided what to do with the others but I'm a borderline hoarder when it comes to cool stuff.   Just looked on Ebay and there are a bunch of used less heavy duty mast systems from the same manufacturer for $1000 or more.   I can't believe my nephew only scraps everything for metal content and doesn't try to sell stuff outright.   Thinking his contract with the military might require him to scrap it.
« Last Edit: December 31, 2021, 10:56:30 PM by rpegg »

Offline Bashy

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Re: VP2 on surplus antenna mast system
« Reply #4 on: December 31, 2021, 10:56:13 PM »
It sounds like you know what you're doing  =D>
You just had to mention about the other masts didn't you  :P , if it didn't cost so much to ship i would have bought one off you, whilst mine is aluminium (alloominum  :P  ) lightweight, its a 10m (33ft) mast but to help keep some rigidity I've kept it to just over 9m and ima stickler for spec so would really prefer the 10m or higher to counter the 2 storey houses over the back but i spose ya have to play with what ya have and put up with it. Youre a lucky chap. If i was loaded, i would have gone with a lattice job and no guylines (2x3), i spose you only need the 1 set of 3 guys for that beast?
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Offline rpegg

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Re: VP2 on surplus antenna mast system
« Reply #5 on: December 31, 2021, 11:09:28 PM »
The instruction manual (written for military grunts) says that the 4 guys I'm using were good for the height I'm at.  4 lower and 4 higher if I go all the way up to 50ft.   Actually the guys that came with the system are nothing more than paracord.   Probably because it was meant to go up quick and pack up, over and over.   I decided to use metal cables instead for longevity.

The entire mast system is aluminum; tripod, masts and arms.   The pipe sections are thick 3" aluminum pipe.   I can manually lift the 7 sections with the weather system installed but for the sake of my back will probably use the built in winch if I go higher.
https://blueskymast.com/mast-systems/al3-lift-series/

Offline Bashy

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Re: VP2 on surplus antenna mast system
« Reply #6 on: December 31, 2021, 11:17:51 PM »
Wish mine was winch, it really does start on my back. Good call on the wire, paracord degrades in the sun, I found that out this summer when I used it to guy a parasol, whilst it didn't break, the outer sheath did, it  crumbled apart showing the white inner.
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Bashy

Offline rpegg

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Re: VP2 on surplus antenna mast system
« Reply #7 on: January 10, 2022, 10:09:25 AM »
I raised the entire VP2 27ft off the ground 
Your temp, dew point/humidity, and rain data will all be skewed.

I will move the anemometer higher and the temp/rain bucket lower in the next month or so.   It's butt-ass cold out there right now.   A little concerned that by lowering the ISS I might degrade or lose the signal to my repeater 1000ft away through the woods.  But I'll deal with that if it becomes a problem.

That aside, I know what the recommended heights are but just wondering...   It is logical that the anemometer should be at 33ft and the temp sensor should be about 6ft off the ground for a standard, but wondering why the rain bucket should matter?   You wouldn't want it 100ft up but can't for the life off me figure out how there would be any difference in rain volume at 5ft or 25ft.   Makes it easy to maintain but the standard seems arbitrary.

Offline Bashy

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Re: VP2 on surplus antenna mast system
« Reply #8 on: January 10, 2022, 10:15:23 AM »
The bucket would be better lower as it would be less chance chance of moving in the wind thus tipping the bucket
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Bashy

Offline mcrossley

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Re: VP2 on surplus antenna mast system
« Reply #9 on: January 10, 2022, 10:30:07 AM »
Plus the closer the ground generally the lower the wind speed, so you have less wind effect - blowing raindrops out of the collector for a lower reading at higher speeds.
Mark

Offline Bashy

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Re: VP2 on surplus antenna mast system
« Reply #10 on: January 10, 2022, 10:33:48 AM »
Plus the closer the ground generally the lower the wind speed, so you have less wind effect - blowing raindrops out of the collector for a lower reading at higher speeds.

Good point, i knew there was a better reason lol
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