Air Dehydrator

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sallen
Posts: 99
Joined: Sat May 09, 2015 8:39 am

Air Dehydrator

Post by sallen »

Looking for suggestions on a good air dehydrator. This is for a directional AM with a 1750' of 3' that needs to be pressurized. Bought a new RFS dehydrator four years ago and it is not pressurizing any more. Who else make a good dehydrator. I'm wondering if the RFS unit was undersized for how much transmission line was being pressurized.

I'm able to isolate the three separate 3" lines and checking how much pressure is being lost in each line.

Any one have experience sending in the RFS units in for repair?
jammerdave
Posts: 128
Joined: Tue May 31, 2011 9:03 pm
Location: West Sacramento, CA

Re: Air Dehydrator

Post by jammerdave »

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kkiddkkidd
Posts: 961
Joined: Mon Dec 03, 2007 11:13 am
Location: Lawrenceburg, TN

Re: Air Dehydrator

Post by kkiddkkidd »

sallen wrote: Tue Nov 03, 2020 11:05 am Looking for suggestions on a good air dehydrator. This is for a directional AM with a 1750' of 3' that needs to be pressurized. Bought a new RFS dehydrator four years ago and it is not pressurizing any more. Who else make a good dehydrator. I'm wondering if the RFS unit was undersized for how much transmission line was being pressurized.

I'm able to isolate the three separate 3" lines and checking how much pressure is being lost in each line.

Any one have experience sending in the RFS units in for repair?
Does your dehydrator run constantly or nearly so? Usually those units will last a life time at normal run time.

Running constantly... They may only last a few months or years. Does the compressor make bad noises as it runs? Can you feel air being pulled into the compressor inlet? I can't recall a single worn out or damage compressor that didn't make really concerning noises when it ran. I have also had issues over the years where a random fitting vibrated loose inside the housing and was releasing the air before it got to the output. Ironically, this seems to mostly happen on dehydrators that run too much...

IF the line has very low leakage, the dehydrator size doesn't really matter (within reason) but if you have a lot of leakage, the leaks need to be addressed or it is going to be hard to make any dehydrator last very long. Don't confuse pumping more CFM's into the line as fixing the problem.

Someone posted a link to 101telecom. I have had clients send them compressors and they seem to do good work but the shipping cost can be an issue from the east coast.

Good luck,
--
Kevin C. Kidd CSRE/AMD
WD4RAT
AM Ground Systems Company
http://www.amgroundsystems.com
KK Broadcast Engineering
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Ray
Posts: 78
Joined: Sat Mar 22, 2014 10:04 am

Re: Air Dehydrator

Post by Ray »

Most of the folks at work like to now order what I call small "baby" units that are rack mounted. They have very limited air volume capacity. Seems like folks are always chasing small air leaks since the duty cycle goes high due to the limited air volume. I remember a few years ago, we spent about full day trying to get a computer to interface with one of the new units. All this was never an issue with the older units. I agree with Kevin, the older RFS or Andrew units last a very long time and usually have lots of volume capacity. I see them on Ebay for a couple hundred of dollars.

We tried one of the newer membrane type units a few years ago. They can clog easily if any oil gets into the line. They are very compact. We never started using them.
sallen
Posts: 99
Joined: Sat May 09, 2015 8:39 am

Re: Air Dehydrator

Post by sallen »

Thanks for the replies. Does any one use an inline air filter after the dehydrator? I have seen them start to spew stuff when the fail. Thinking of what kind of protection filter I might be able to use after the dehydrator.
Kelly
Posts: 558
Joined: Thu Aug 21, 2008 5:32 pm
Location: Washington D.C. Area

Re: Air Dehydrator

Post by Kelly »

Hi Steve,

There should already be plenty of filtering in the dehydrator. Besides the filtering a desiccant provides, usually there is a moisture trap and filter in line too. If you're seeing gunk puking out of the dehydrator, there's a good chance it's got internal issues.

As other's have mentioned, they wear out eventually. Andrew/Commscope dehydrators can be refurbished.
Skype:kellyalford Twitter: @KellyAlford
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