How to use your racks and avoid unspeakable engineering horror

On most equipment racks you will find the following pattern of holes:

** * ** * ** * ** * **

No, it was not drilled by a drunken woodpecker.

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But this gear was installed by a drunken bonobo at 4 am.

See the holes with the wider spaces between them? Good… IGNORE THEM! They do not exist! You never saw them. Fnord.

See the closely spaced holes? Imagine they’re the dots on a double 1 domino. This means there’s a center line between them. See attached photograph. The center line will be the edge of each piece of equipment to be mounted.

Why are the center holes there? Okay… Fine, I’ll admit to their existence. Begrudgingly…

Some oddball accessories like cover blanks and cable lacing bars may be screwed in here. In the case of cover blanks it’s usually on weird ones that have a single hole in each end of a 1U* high blank. If you install a lacing bar this way it will be in the middle of one rack unit space – handy for the rear rails behind a patch panel.

Otherwise, do not use them unless you really have good reason to.

If you do mess this up…. Well, look at the wonderful mess in the photograph. Huuurrrrrgghhhhhhhhhbbllll.

Is any of this real? None of this can be real, right?

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No way. This must be the ergot talking.

I’m beginning to wonder if this city even exists or if this has all been a prolonged mass hallucination caused by ergot growing in the croquettas or something… Kinda like how the ergot growing in the bread in Salem led to the witch trials

There’s just no way any of this is real

Well if it’s hallucination it’s a really good one because dude I can smell the hot vinyl and feel the warmth from that bad crimp splice there that likely breaks about 23 parts of the National Electric Code

The Tropical Meta Prediction Center issues its forecast

This is what you will be seeing in all broadcast media in the near future and oh what a glorious time to be alive

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And every last inch of me's covered in Gaston

The above image was used in the fabulous YouTube Poop “Beauty and the Beastiality”.

You know at this point that storm could leave me floating out to sea and I couldn’t even be mad because I’m just going to keep thinking of Gaston’s song.

Fictional or not, he’s the only dude I know of who can break a belt with his neck muscles. I still can’t really grasp whether that’d be realistically possible or not. Does human anatomy even work that way? I did snap the collar button off a dress shirt once, but I feel that’s not much of an accomplishment. It was actually kind of amusing at the time because it fell right in my hand.

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Seconds later, a random person suffered the curse of falling trousers.

I dunno, maybe the only reason I’m posting that is because it’s amusing that it momentarily looks like he’s
wearing a collar.

Try as anyone may, you can’t scrub the old goth out of me. Old school goth troll. That’s me.

Harbor Freight has yet to learn about “quality fade”

Quality fade is the unfortunate massive ugly side effect of Chinese outsourcing which causes a product to become utter garbage with successive manufacturing runs.

I am suspecting what you’re looking at here is two different runs, one specified to be cheaper than the other. The new cheapened one got a different SKU number, 93928. The original was 62778. The original weighs about twice as much and well uhhhh

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The bins have all buckled out of shape!

Ridiculous. As for why I’m even here, you can’t buy anything like this in any of the other stores around here for less than $20 each and they’re built like the one on the right. At least they still had the older ones.

Another day, another dehydrator

Previously I posted about the Dielectric dehydrator. Here’s another common model, the Andrew / CommScope …. Newer models are controlled by this honking weird motherboard.

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This thing's some engineer's iron clad job security

Basic parts:

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Upper left: black top hat is the air inlet filter that Andrew claims is accessible from the front panel (big fat lie), twist cover and pull off to open. Felt element is easily cleaned. Do not oil, use dry.

Pump: A field rebuildable diaphragm pump.

Center left: vent valve.

Bottom left: Spaghetti Junction.

Center bottom: output pressure regulator.

Bottom right: Coalescing filter bowls. Accessible at front panel.

Right: Molecular sieve unit and air tank.

Top center: Humidity sensor, pressure alarm switch, power input, air output.

Just so you know I didn’t simply open this for fun, here’s what happened on this unit.

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Sliiiiiiimeeeeeee!!!!! The vent valve was blocked and the unit couldn’t drain, so it threw a humidity alarm.

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Water was building up in the coalescing bowls and not being purged. That line at the bottom leads to the vent valve.

How it works: The spaghetti board starts the pump. Air passes left to right through these filter bowls, actually going through them backwards best I can tell. That is to say it enters the inner part of the fiber filters. Believe it or not there is a good reason for this. It then flows through the molecular sieve unit which absorbs moisture, passes through a check valve (where?), and enters the storage tank. From there the regulator allows enough air to pass and pressurize the line. Usually it’s set to like 3 psi.

The tank pressure is gradually increased up to 40 psi at which point the controller stops the pump and opens the vent valve.

When this happens, the pressure in the molecular sieve drops rapidly with outflow to the input side. This causes water droplets to form and be ejected. The water blows back into these two bowls and is vented along with the air via the drain.

Since this is taking place backwards, the bowls are backwards so the droplets will hit the filters on the proper side and fall downwards.

There’s method to the madness, see?

To return the unit to service, I backwashed the vent valve with the air coming from the pump and a snot rocket launched out and went….. Well, it’s never been seen since. Who knows.

It works now, that’s the important part.

And now some hot electronics porn. Here’s a Harris Broadcast ATSC receiver….
Hardcore model.

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Top left: RF and IF board. Right: 8VSB demodulator. Bottom: big mama power supply.

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The 8VSB demodulator.

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Video stream decoder and video output

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Pin count anyone?

This. Unit. Was. Not. Cheap. To. Build. Daaaaaaayuuuummmnnnn

I accept your challenge

I wish to test this claim.

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"15,000 watts"

Can I borrow a big ass shortwave rig for a moment? I’d like to see how many milliseconds this lasts before becoming a plasmoid cloud of hissing metallic gas.

Don’t leave your radio near me

Because I’ll start playing with it.

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The only thing that prevented my coworker from winding up with memory channels named after colorful air-entrained car wash products is that I really didn’t like that touchscreen user interface. A+ for cleverness though. I’ve heard the Yaesu System Fusion digital mode on these radios works very well and sounds great.

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