Back in early 2022, I was fresh off my first major solo project—installing a runs of RFS Cellflex cable and connectors for a new tower site. I thought I had it all figured out. I'd checked the connector pull tests, the sweeps looked clean, and the GPS coordinates for the RFS antennas were dead on. Everything was textbook.
But there was one piece of advice everyone kept giving me: 'You have to let the dehydrator run for a full 24 hours before you even think about pressurizing the line.' I heard it from the senior tech, from the RFS support rep, and from a guy on a forum who'd been doing this since the 90s. I figured they were just being overly cautious. I skipped it. I pressurized the line after about four hours. The pressure held initially, and I documented the install as complete. Honestly, I thought I was being efficient.
A month later, I got a call. The site was reporting an 'Under-Pressure' alarm on the RFS dehydrator. I drove back out, assuming it was a faulty unit. It wasn't. The issue was entirely my fault, and the lesson I learned that day fundamentally changed how my team handles every single pressurized installation now.
The Surface Problem: A 'Bad' Dehydrator
The alarm log on the RFS dehydrator showed a steady, slow pressure loss over three weeks—not a sudden drop like you'd get from a cut cable or a blown connector. The unit's internal diagnostics all checked out fine. The pump was running, the desiccant tower was cycling. It looked like a very expensive, very reliable unit that was just failing to maintain pressure. My first instinct was to swap it out under warranty. That's the easy answer, right? 'The equipment is bad.'
But something nagged at me. The pressure loss was too consistent, too linear. A mechanical failure usually just means it stops working entirely. This was more of a slow leak. So, instead of ordering a replacement dehydrator (which would have been a $1,200 RMA and a two-week delay), I decided to do a proper isolation test on the entire transmission line system—the waveguide, the connectors, the jumpers, all of it.
The Deeper Cause: The Connector’s Dirty Little Secret
Here's what I found: The issue wasn't the dehydrator. It was the connectors I'd installed a month prior. Specifically, the RFS 7-16 DIN connectors on the main run of LCF12-50J cable. They were torqued correctly. The center pin looked perfect. But during the installation, I had failed to properly clean and dry the inner conductor before making the final connection. A tiny bit of lubricant and moisture from the compression tool was trapped inside the connector interface.
Now, here's the part that blew my mind—and the part almost no training video shows you. That tiny bit of moisture doesn't cause an immediate short or a VSWR spike. You can sweep it, and it looks perfect. But under pressure, that moisture acts like a slow-release valve. The dry air from the dehydrator absorbs the moisture inside the connector, becomes slightly heavier, and then bleeds out through the microscopic tolerances of the connector interface. It's not a leak. It's a 'breath.' The RFS dehydrator was operating perfectly; it just couldn't keep up with the fact that my connector was actively 'off-gassing' moisture into the dry air it was trying to maintain. (I later learned this is a well-documented phenomenon in high-humidity environments, but I'd never seen it in any quick-start guide.)
'I only believed in the necessity of a full 24-hour dehydrator cycle after ignoring it and creating a $1,200, month-long service headache for myself.'
The Real Cost of a Skipped Procedure
Let's break down the actual cost of my 'efficiency' in September 2022:
- Direct Costs: $0 for the dehydrator itself (it was fine). But I spent $320 on a weekend site visit, diagnostic gear rental, and new connector kits to re-terminate the two offending ends.
- Indirect Costs: A 1-week delay in turning the site over to the network operator. The SLA penalty on that contract was $150 per day.
- Credibility Cost: Explaining to my boss that the 'efficient' install I was so proud of had actually failed. The $1,200 RMA request I almost submitted would have been a complete fabrication of a problem.
That's roughly $1,200 in wasted money and a significant credibility hit—all because I didn't let the RFS dehydrator do its job for enough time. Since then, we've caught 7 potential errors using a pre-pressurization checklist I created, most of them related to incomplete drying of connector interfaces. That checklist has saved us an estimated $8,000 in potential repeat site visits over the last 18 months.
The Simple Solution (That Everyone Ignores)
The solution is boring. It's not a new tool or a software update. It's patience. According to RFS best-practice documentation (which I now keep bookmarked), you should:
- Connect the RFS dehydrator to the line.
- Let it run for a minimum of 24 hours to dry out the internal air volume and any residual moisture in the connectors. (I now use a 36-hour rule in humid climates.)
- Only after that period, set your final pressure and conduct the 48-hour hold test.
That's it. The technology—the RFS dehydrator, the Cellflex cable, the connectors—works perfectly when you follow the fundamentals. The 'magic' isn't in the box. It's in giving the box the time it needs to overcome our tiny installation errors. This was accurate as of my project in September 2022. The fundamentals of pressurization haven't changed, but always verify the specific model's manual at rfsworld.com for current procedures.
