Frequency hoarder (n). One who desires to add so many frequencies to the internal memory of their scanner or other radio device that they can easily fill the 1000 channels on a GRE scanner or any of the recent Yaesu radios* and find themselves dejectedly trying to figure out what won’t make the cut.
I am guilty of being a frequency hoarder. When will the scanners just read a CSV file off a microsd? I’m waiting…
* except for the 817/857/897 which only have 200!! Why, yaesu? Why did you make three rigs that beautifully span DC to 512 megacycles with no gaps in am/FM/ssb/cw/wide FM and then only give us 200 pigeon holes for our frequencies?!
This little monster showed up at my doorstep and I decided to see if I could get it running again. It’s an air dehydrator, which compresses air, separates the moisture out and ejects that, then uses it to pressurize an RF transmission line to avoid moisture intrusion.
The instructions mentioned a humidity sensor inside that has to be replaced every couple years of operation. I removed it and took a look, it showed no signs of wear or contamination. Upon powering the unit up I got a humidity alarm and the unit would just vent air via a “humidity bypass” burp valve inside which prevents it from firing wet air up the feedline should something go wrong internally.
After it ran on my bench for a while, the humidity alarm cleared and it pressurized its tank and was ready for business. The humidity sensor goes in that brass block with the 115V warning on it; the two cylinder blocks behind it contain the moisture absorbing material. The timer to its right controls some pneumatic valves which drop the pressure in the dessicant cylinders to zero every 30 seconds while the pump is running, firing air (and WATER!) out a waste hose in the back.
On the right is the Gast pump that compresses air up to 40 PSI to run the works. On the left is all the control logic. The other unit I’ve worked with before is an Andrew DryLine, which just has one simple programmable logic controller board in it. This one, well, looking at it makes me think that the people who designed it chose to build their job security into the control logic – what even IS all of that?! 😉 The four pole contactor at the bottom doesn’t appear to actually be what controls the pump turning on and off. I… don’t even know. It works, that’s the important part. The humidity bypass valve is under that threaded hex nut/nipple on the left, and the time delay relay brick below it appears to be responsible for firing off the Excess Run alarm should a pump run cycle last too long (usually, this would signify an air leak!)
The pump is cycled on and off by a simple Square D Pumptrol air pressure switch… off at 40 PSI, on at 20 PSI.
BY THE POWER OF GREYSKULL!!!
An amusing note I found on the Gast pump. I’ve seen similar pumps used for a lot of laboratory applications including as low vacuum pumps, for things such as providing suction in dental offices (that slobber extraction hose they hang in your mouth)… Well, once the pump’s been used like THAT, they don’t want it back! Can you really blame Gast? 😉
The Gast pumps are field rebuildable with a seal/gasket kit to keep the unit in service. On this unit, loosening four screws flanking the gray upper front cover is all you need to do to be able to reach in there and pop open the air inlet filter on the pump for cleaning, check the tank pressure, and get to most of the control logic. This is a sharp contrast to the Andrew unit I’ve worked on where you have to remove the whole thing from the rack and pop eight screws from the top cover to get to the filter, which the datasheet claims is behind the front access panel (NOPE!!!).
These pieces of turd infect some Harris Broadcast products to this day.
Sure, IDC connectors seem like a good idea at the time except… A) they use them on stranded wire, making them failure prone, and B) they put them on cable assemblies that experience vibration from blowers….
It’s a surefire recipe for very difficult to troubleshoot problems.
High power broadcast feedlines are usually pressurized with dry air or nitrogen gas to lock out moisture (which would lead to a Very Expensive Problem). The Andrew/Commscope pressurization gear for doing this has weird tubing fittings on it for the air hoses that hook up to the feedlines. I tried doing a job on one of these systems using little brass tubing fittings from Home Depot and it just didn’t all work right, it was a pain in the /dev/ARSE to get everything to stop leaking. Come to find out, well… The fittings are actually a different system – Parker Poly-Tite.They’re apparently most common in dental office equipment and car washes.
“Radio Engineer NEEDED ASAP, Duties shall include: Plumbing and toilet repair; Vehicle maintenance and repair; General building and grounds upkeep, modifications and repair; Removal of derelicts and other undesirables from building; Jewelry repair; emergency shoe and garment repair; kitchen appliance repair; office moves and logistics as requested; repair employees electronic equipment; equip, setup and tear down for remote broadcast as requested; install, maintain all phones, computers, as well as associated routers and networks; provide instant desktop support for all running OS and installed applications; Maintenance and upkeep of all FCC related compliance and record keeping matters; repair and maintain towers, transmitters and other broadcast equipment. Must supply own transportation and communications; On-call 24/7 is a must as well as a good attitude and willingness to take direction from anyone who ask….”
This is what a particular Sprint PCS cell site in southwestern Miami-Dade County, Florida, looks like inside.
Shield your eyes, it’s horrible. No, actually, you will want to shield your eyes because the batteries were installed so badly that I felt the need to place some cut-up pieces of a plastic container in between the battery terminals and some aluminum-cased monitoring widgets that were sitting on top of them to avoid an electrical fire. (Upon testing the batteries I found then to be at about 10.1 volts DC. FAIL.)
And this kind of thing is why I trust ham radio for communications more than anything I pay a mystery team for “service” on. 🙂