I have heard around 4 psi is a good pressure to keep your line dry. Some opt for lower pressures of 2 or 3 psi when the system is leaky causing frequent nitrogen tank changes or dehydrators to run too much. Many dehydrators don’t have a storage tank followed by a regulator to keep the pressure constant. The line pressure varies between lower and upper limits between runs, such as 3 to 6 psi.
Whether you opt for nitrogen or a dehydrator usually depends how leaky the line is. Dehydrators are best when the line is so leaky a nitrogen tank needs to be changed too frequently. At one of our sites the nitrogen tank needs to be changed only once a year so we are staying with nitrogen. At another site the tank needs to be changed every two or three months so I may put a dehydrator in next year’s budget. Two or three months isn’t convenient during the winter with deep snow on the mountain.
Dehydrators come in various sizes and specs so be careful what model you order. Some are designed for low pressure microwave systems that output less than 1 psi. Some output only about 0.2 cfm which are good for smaller systems. If your antenna is a 6 bay fed with 3 inch line your probably need a larger dehydrator. The Customer Service should be able to calculate the size you need for your system.
From: Steve Tuzeneu [mailto:email@example.com]
Sent: Friday, November 17, 2017 8:59 AM
Subject: [CRTech] Line Pressure
I'm curious to know how much pressure you put into your transmission line and how you arrived at that number. I want to compare that to what we set ours to.
How many pounds of pressure do you set your line pressure to?
Also, what do you use? Do you use a nitrogen tank, dehydrator, or some form of air compressor with desiccant at the output. And why?
I find it disappointing that Phartronics may be out of business. As much as Willie loves the name of the company, they made a good product that we have used at most of our transmission sites.
Have a great and quiet Thanksgiving!
Charlotte , NC 28241-7300
704-523-5555 Extension 138
Member: Society of Broadcast Engineers
G.R.O.L./N1XXE-Extra Class Operator