Transmitter sites used to be kinda different – it was not uncommon for them to be manned daily, if not outright equipped with an engineer in residence. Now they just tend to have weird ghosts and stuff. I’ve only ever seen the name O’keefe & Merritt on appliances in old transmitter site kitchens. Ok then?
Yeah, I was down at the tower again. 😀
Ok just gonna switch out this GatesAir exciter, let’s see, move all the connectors over and hey wait what’s this
The back of the exciter is just a db 9…
Ok, I’m done….. No wait hhhhhhhhhhhhhhhhhhhHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
WHERE DID YOU EVEN FIND A CONNECTOR THIS POWERFULLY CURSED
Hell it’s like a Phoenix Contact header had a severe case of multiple personality disorder and the adapter was nigh impossible to remove with the exciter in place and thanks I hate it.
Yesterday I noticed while at the hall of suds that CNN was kinda awkwardly taking someone else’s network feed from the CPAC conference* to air leading to a kinda Dueling Chyrons situation.
Given a little more thought, I don’t blame them, would YOU want to attend that crap? I’m pretty sure among other things it’s an absolutely guaranteed COVID-19 superspreader event, but then it’s… just ew.
* pure uncut cringe.
Anyway let’s just continue shitposting things
Can you just lob these filthy things in the wash? I wish.
grumble grumble blower vfd not configured to automatically ride through and restart after power glitch grumble
Oh, I have such a love-hate relationship with some manufacturers.
Now… I had previously made a vague shitpost while working on a Harris Apex A2X exciter. This would have dated back to, well, when they were Harris Broadcast before the spinoff that left them independent as GatesAir, with another division becoming Imagine Communications
Imagine Communications…. Because they aren’t necessarily ever going to work outside of your vivid imagination
Anyway let’s just get right into YELLING IN BROADCAST ENGINEER. First stop: The Apex M2X oscillator board.
Frequency stability is vital to generating a good solid digital TV broadcast signal. The Apex M2X features a disciplined OCXO (Oven Controlled Crystal Oscillator) with several options as to how to ensure proper longterm calibration – it has a GPS receiver, 10 Mhz external reference, and 1 PPS external reference options provided. More on OCXO references here (this describing a more basic, free-running one, without sync inputs). However, the OCXO itself is, uhhhhhhhhhhhh
WHAT DID YOU DO HERE
WHAT IS THIS
WHAT IS ANY OF THIS
YOU GUYS JUST GLUED A BLOB OF PACKING FOAM OVER THE OSCILLATOR AND A LINEAR VOLTAGE REGULATOR WHY DID YOU DO THIS
LOOK AT THAT BULGING CAPACITOR OF HAPPINESS ALL UP IN THERE OH BABY
I wanted to peel this crap off but I was fairly confident that if this is anything like the antistatic foam that ICs used to come packed in, it may have broken down and corroded parts under it and I’d be faced with irreplaceable parts that went out of availability two years before they sold this exciter crumbling to dust. So I left it alone. It only has to last about another year, if even that. I hope. Did I mention HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH? Because HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
So. Let’s move on to the power side.
The power supply is along the left wall of the exciter. On GatesAir’s admission, the power supply pretty much expires and becomes a ticking time bomb after 5 years – power it off and it will never ever start back up again.
But that’s unrelated to, uhhhhh, The Internal UPS Thing Of WEIRDNESS
For unknown reasons they felt the need to give the unit battery backup. It does not fully power it, like, the RF output disappears once it’s on battery. I think all it does is keep the controller with the RTAC data* in memory alive, and keep it from having to entirely run through the several minutes long boot process following a momentary power glitch.
It is, however, FUCKING RIDICULOUS.
On later versions it uses a lithium ion battery which consists of three 18650 cells, but rated at only 1.5 amp hour, which suggests… some 18650s of hilariously low quality. Behind the board is a charging / BMS circuit that steps the battery voltage up to 12V to keep the exciter powered. On earlier versions, they went through all the trouble of building this elaborate charger/step-up board, similarly…..
And then, waaaait for it—–
Ok, take a good look at this, and prepare yourself for the description of what you’re actually looking at: someone… went through the trouble of getting a spot welder in house and welding tabs to unmatched dumpshit tier** Energizer retail packed NiMH cells.
Because, uh, only the finest with Brand HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH.
* Sorry, I am not currently in a sufficiently coherent mental state to describe what RTAC does, other than that it is Fucking Magic and if the Fucking Magic doesn’t work, the signal comes out on air as distorted non-decodable dog turd
** only slightly better than Duracell
It doesn’t work, we have no idea why.
It works, we have no idea why.
Well, if you look up the brochure for this thing they say up to 300 lines resolution…
Thing’s so fuzzy when I first plugged it in I thought it needed a focus adjustment. No… It just needs…… actual resolution.
Seriously, what were you thinking, Panasonic? I’ve got dank memes with more pixels than this.
How many people came away from using these monitors with a lifetime of eyestrain?
“but the rf swirling around in the circulator will keep it cool…”
CIRCULATORS DO NOT WORK THAT WAY! GOOD NIGHT!
this has been a high quality shitpost
Gingy would like to remind you every time is the right time for petting your feline assistants.
The cool looking radar is sadly no longer in use. Anyway, as for the title, we’d been having issues with the big transmitter here for months and it just wouldn’t run on all three cabinets. Its intermediate power amp had been giving issues on one cabinet and our other engineers had been over the manual and talking with tech support for months, it just wouldn’t make wattage.
Finally the solution was to not trust the manual. It said the arbitrary “IPA Gain” number was supposed to be between 100 and 450. It was set on 100 and that led to only 9 watts drive to the IOT tube — 150 was needed. The solution in the end was … set the gain to about 520 or so. Amusingly, it only raised up from 9 watts once I went past 420.
420 blaze it
One of the other engineers had this Printrbot Simple Metal that he hadn’t gotten working so I took it back to play with it through the boring Thanksgiving morning shift. Despite it being a SOLID chonker, the carriage plate was bent up causing the hotend to hang at a weird angle, and some screws were loose or incorrect, so I fixed that and got it extruding. The only thing I wasn’t able to do which bugs me was to get a bootloader onto the Printrboard in there and load it with a newer version of Marlin supporting mesh bed leveling. This one is old and appears to take no parameters to G29 – it probes only three points. Weird. I couldn’t get Atmel’s FLIP utility to work and had issues with building Marlin for that particular cpu — it seems like you either have to use the toolchain for the Teensyduino++ or use PlatformIO, neither of which wanted to cooperate. Thus, it remains on old firmware.
A while back I noticed, hey, we’re actually using a…. plurality…. of 2000 watt halogen Fresnel fixtures in our studio. I brought up to the network’s one lighting guy that I’d found this cool (literally!) VisionSmith ReLamp System that includes a 275 watt tungsten lamp colored drop-in replacement for the CYX lightbulb… and can apparently also let you use acrylic Fresnel lenses which increase the fixture’s output even farther. He gave me this look like I’d just waved a dead skunk in his face, so I dropped the subject on the spot. Oh well, someday we’ll be able to explore MODERN technology 😉
So I’d mentioned this to someone in a thread on Facebook who got sticker shock seeing that the LED CYX replacement costs $945.25 from one vendor. The halogen CYX costs $30 (surprisingly, that’s a little less than the common HPL bulb used for Source Four lamps). I immediately thought to myself the total cost of operation must be VERY VERY much lower so I ran some back of the napkin numbers on it. These do not include the cost of air conditioning to remove the waste heat from the space as I don’t know how to calculate that off the top of my head. This is just for the bulb cost and electricity cost:
Average US electricity cost: 13.19 cents/KwH.
Rated life of the VisionSmith module: 50K hours
Rated life of the CYX halogen: 300 hours
Cost of electric power to run CYX bulbs for 50K hours: $13,190
Cost of 167 bulbs (!): $5010
Total cost of operation: $18,200
Cost of electric power to run the VisionSmith for 50K: $1814
Cost of one module: $945.25
Total cost of operation: $2759.25
Yeah—- I’m pretty sure which one I’m gonna go with.