We had some crazy winter storms and the site I lovingly call Shit on a Shingle lost power. When the power came back after a couple days, the station didn’t.
Found this little derpshit howling away as usual with no output. Front panel buttons and remote interface were unresponsive. Power cycled it and the controls came back but still no output. I warmed it with a space heater for a while and if fully returned to service.
I know some transmitters don’t like extreme cold, but this thing had only reached about 34 degrees at the lowest.
It had a really shaky start too, the front panel indicated 1750 watts forward 0 reflect, but no PA current, and it wasn’t audible on the air. I set it to 500 and it was audible for about a block down the road. As incoming snowstorms chased me from the site I heard it just gradually chatter and wheeze back onto the airwaves.
Hello, Transmitter Fairy, what do I have to leave under my pillow for you to leave me a nice Nautel VS2.5?
Please don’t disturb the kitty on the pillow.
This is, incidentally, the same site where the combiner horror used to live. Yeah, that one that never worked at full power until the whole system was sent out for service for a few months then exploded after less than a day on air.
The stock heat block on the Malyan (200?) / Monoprice Select Mini v2 3d printer is a special sort of awful. Out of the box I had weird issues. PID autotune would fail with a “Temperature too high!” error, and I threw various sets of PID values at it to no avail. What’d happen was every time the heater came on, a 5 degree C overshoot was virtually guaranteed, leading to lots of print stringing. It almost seemed like the temp would rise for about TEN SECONDS after the heater shut off. I suspected poor thermal coupling between the heater cartridge and heat block, and ordered a $10 E3D V6 clone off eBay intending to just use the block it came with.
I wound up doing just that.
The E3D silicone sock even almost fits it! Uh, not great though. I cut away one tab to make room for the thermistor retaining screw.
And now, on to the block of horrors. It had this execrable kapton / fiber covering that disintegrated when touched.
Bad picture but you can already see it looks rough, right? It gets worse.
There’s the heater bore. It doesn’t look like the hole was drilled as much as ice picked.
The grubscrew that locks the heater in place, and the questionable looking threads for the nozzle and heat break…
Seems to me the whole damn thing was a heat break 😉
Yeeeeah, so I haven’t fine tuned it with the new block in yet but just switching the heater on at the front panel and watching the temperature reading, it ramps up and just locks in with occasional undershoot of maybe 3C. Much better… Maybe the PID tune will even work now!
Maxtor 1/4 height 3.5″ drive. I forget the name for these but they were some of the least reliable hard disks ever made. One very odd aspect of this design (possibly contributing to the problems?) is that it only uses one platter and only one side of the disk!
The head stack is comically simple … one thin film write head and one MR read head.
These drives usually lasted a year or so in service then provided a brief period of degraded super slow service during which you could save some data…. Then they’d up and die.
These images were saved to a Samsung micro SD card with about three times the capacity as the drive pictured which has been in service for about five years.
After three hellish days of having dispatchers lie to me and tell me to stick around waiting for a tech that’d never come, waking me up at 5 AM and insisting I stick around until after midnight, all sorts of broken promises, and an overseas call center keeping THE ACTUAL TECHNICIAN waiting on hold for hours and hanging up on him repeatedly, our office has phones and almost half the internet speed we’re paying for!
This is still an improvement…. SADLY…. Now we’re no longer stuck with this clusterfuckery as our only link to the outside world. In case you ever find yourself shopping for business Internet and managed VoIP telephone services, LOOK ELSEWHERE and do yourself a favor. As janky as Comcast’s business fiber / metro ethernet / VoIP offerings are, with the vile potentially self-destructing phones, THEY ARE STILL BETTER ABOUT UPTIME… SORT OF. You know, when they aren’t having failures due to having installed everyone’s stuff to a fiber patch panel somewhere with dodgy uxcell brand fiber jumpers that arrived in a beat up China Post epacket. (I’m not even kidding here one bit)
Another PTek. Another questionable combiner. This one doesn’t even make any damn sense. I’m scared to open up the top of the transmitter to find out why it’s wired the way it is. The resistors are sitting on top of that hand cut piece of random PTFE and will cause a fire if they ever dissipate any significant energy. This is inside an FM2500PS transmitter.
This is a two port Wilkinson combiner that combines together the output of the left two pallets and the right two pallets. Why it’s floating on the thick PTFE slab, I cannot understand— these resistors appear to have the terminal configuration in which one lead of the resistor is the heatsinking base, and the other is the solder tab which just passes right through otherwise. WHY IS THIS BOTH INSULATED FROM AND ELECTRICALLY CONNECTED TO THE HEATSINK??!! Basically, what WILL cause this combiner to blow chunks would be any imbalance between the left and right sides of the transmitter – a single module failure will roast the entire rig. Catastrophically. See video below.
The lower line from each side goes to the start of the harmonic filter network, where they are just unceremoniously smashed together. This is… about the caliber of a badly built CB amp.
Dare I open the top and look around or have I suffered enough torture already??
(edit: yes… sadly I did!!!)
Page spam cut— click to continue. If you dare. I warned you, and Alex Hartman always warns ME not to open these transmitters and look around. But I do anyway. Then my brain hurts. ARGH