May I just take a microsecond here

Hey, it’s me, I want to give you some good frequencies. (The part I’m referring to is the very end, and the bandpass filtered beat you hear in the background is the beat to Eple, which follows it on the album. Eple will sound familiar to anyone who’s ever fired up a fresh install of Mac OS 10.3…)

But all that aside, this is about metrology and frequency standards and things my cat likes to loaf herself on top of because they’re warm.

We’re preparing for the installation of a new GatesAir Maxiva DTV transmitter at work. I was gonna say it’s an ATSC transmitter, but… I’d at least like to hope… it’s ATSC3 ready, whenever that rolls out. Sitting in the space it was going to reside in was a weird old Axcera transmitter that never worked right and was yanked out in pieces to be e-waste’d. Sitting on one of the pallets of refuse left over was the reference oscillator for the exciter, which, interestingly, was just a standalone thing without GPS synchronization. The tub in the middle is an insulated chamber containing an oven controlled crystal oscillator. Basically, this is an oscillator in a thermostatically controlled heated chamber that keeps it stable. It MUST be allowed to warm up to full operating temperature before use, or, well… it just ain’t gonna be in spec!

(insert commentary here on how silly it is that I’ve seen OCXOs in battery powered equipment that has a shorter battery life than the warmup time)

Most modern stuff uses GPS sync because it’s a good inexpensive way of obtaining a stable reference frequency and timecode. The usual arrangement is to have a voltage controlled oscillator that’s PLL locked to a 10khz timing signal output from a GPS receiver head. Aside from a little bit of phase noise possible in the system, it’s always spot on. This is why you’ll see funky little cone shaped GPS receiver antennas all over the place at broadcast facilities.

Here’s the Evertz system we have that takes GPS time and frequency references and generates our facility master clocks, black burst, and trilevel video sync. I’ve never really gotten that good a look at the way it operates but I think the black burst is generated inside the automatic changeover unit which also has some distribution amplifiers in the back as well. One of the outputs is a 10.000.00000 (I’m not sure how many significant figures) reference which can be used by a wide range of equipment. After having an, uh, experience, with one of these changeover units (see link above) I wisely do not even look at it hard while we’re in anything but 4:00 AM Sunday morning backwash programming. A frame of Grass Valley distribution amplifiers near it is used to distribute its black burst, LTC timecode, and 10mhz signals to where they’re needed throughout the facility.

This will come into play later.

The toroidal power transformer has two primary windings which were series wired for operation on 240vac. That’s why it says 240 on the AC terminal block shield. I swapped them to paralleled for 120.

More pictures and calibration process — onward

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Tuned out

I’m sorry, I can’t put up with listening to the day’s news anymore, it’s all just illogical rubbish, let me just listen to ham radio operators talk on the radio about talking on the radio over a  synthwave soundtrack—

There’s a custom URL option in youarelistening.to but I’m not sure exactly how it works so— try this here. Hit play on this and open the stream link below.

KE6USA Repeater (new window)

Like a spark in the dark

Something I noticed recently…

WiGLE added Bluetooth device scanning and database functionality to their Wardriving app a year or so back. Originally, I would see a few things pop up in it, usually headsets and car entertainment systems.

Now, it seems like everything comes with Bluetooth and no fecking power switch.

This is the result of just leaving scanning active overnight as people and their Bluetooth devices move past. The newer BLE stuff has…. kinda terrifyingly long range.

It makes me think… If WiGLE is scanning this for nerds like me, there’s gotta be some shady-ass analytics company using Bluetooth to track everyone without their consent and selling that data.

Personally I use maybe three Bluetooth devices regularly, and they are all switched off when not in active use. Without trying to correlate addresses to vendors or anything, I’m just going to empirically blame Apple’s crappy AirPods for a lot of these potential tracking beacons.

dave what are you doing DAVE STAHP

I installed this board a couple years ago in Redding and then I see this on Facebook

Congratulations, you win a free upgrade to this shitty old Arrakis 1200 I dragged out of the e-waste bin.

That being said, You Can Decrease The Likelihood Of Damaged Consoles With This One Weird Trick: use consoles with a vertical front surface. Here’s an SAS like that, I stole the pic off someone else’s post and forget where it is but it’s slick.

Many early consoles had this layout, using big chunky rotary faders.

SAS has also replicated this with the Dees Digital, designed to meet Rick Dees’ desire to have a modern board with digital routing but with the classic rotary pots and vertical panel. It’s a beauty.

And now, additional folderol

The PISS

Note to self:

The PISS is a magical thing I came up with using a bog standard off the shelf outboard mixer along with the telephone hybrid to perform a few different functions including mix-minus, mono feed to the console, and stereo feed for recording (jock on one channel, caller on the other) to a computer for polishing up and re-airing later. I should really make a proper CAD diagram of this, but come on man it’s called the PISS, and it’s going riiiight in the shitpost category on this blog. The REC switch box thing is there because the USB interface in use was in the Arrakis MARC-16 console AND LET US NEVER SPEAK OF THAT SHITTY THING AGAIN

Better late than never– the arcy sparky harmonic filter

I forgot to post this over a year ago…

So we were working on the old Continental Electronics 816R that sadly later got nuked by the Carr Fire when we heard a voice come out of the power amplifier.

Uhhh, FM transmitters don’t usually do that.

In addition it kept arcing plate voltage to ground with an irritating snapping sound and restarting repeatedly so it needed some work.

Uh-oh!

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Suds Coleman

In the late 1990s, my since departed uncle loved listening to a few different programs on WIOD Miami. He wasn’t big on sports commentary, which there was some amount of, but he really loved the programs by the late Neil Rogers and Rick and Suds.

It saddened me to learn this morning that Suds Coleman has passed after a battle with cancer.

I’ll never forget one broadcast of his in particular… As a kid, I didn’t really get a lot of the humor of the shows my uncle liked on WIOD, so I didn’t listen that often, but then he and Rick Riley were there to keep us company through Andrew.

Hurricane Andrew rolled into the Miami area on August 24, 1992. Almost immediately, the television stations went dark and a lot of the other radio stations vanished from the dial or fell dead air. However, of all the goofy places you would not expect to be unaffected… the two tower AM directional in the middle of the freaking BAY stayed up, and WIOD still had power. Their building stood on stilts (a VERY WISE design choice!) and everything stayed powered off their generator and fully on air.

Meanwhile, Rick and Suds were up there in the studio looking down, and from their vantage point, it looked like the bay was just knocking on the station’s door. It probably was, considering how vulnerable the area is to storm surge. The WSVN studio next door had three feet of salt water in it and they were off air. At this point they had lost all telephone lines and other means of communication with the outside world, but were still on the air…. and they were just providing commentary on the objects and satellite dishes from WSVN flying past their windows.

They didn’t have much to report other than that due to the loss of communications, but hearing them on the air from a darkened house buried in about 30 feet of uprooted trees with flaming pieces of debris from a nearby tree that was hitting the power lines somehow managed to convince me that we’d all go outside the next morning and everyone else would still be there.

It’s things like that which will always show just how valuable the local broadcasters are to the community, and I thank him so much for his contributions.

[Buttloads!]
… Back at’cha.

The Telos One X Six – that’s dedication

We had a Telos One X Six blow up on us, sadly.

A second unit that needed a power supply was sent over from our other stations down south. as I replaced the power supply, I admired what insane dedication to electronic design went into this monster. Image heavy post follows.

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