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Could fair 2020: Here’s a fried FET, from the sequence of the Unknown Editor. From the particular person source vias and the vogue the nitride is pulled reduction, you need to characterize it’s a millimeterwave effort. The arrangement the busbars are to this level from the active channels, a microwave man did not argue enough over the layout originate suggestions.
August 2019: The following photos attain in from Bernd:
It is the tip result of connecting a log-periodic antenna plan according to a FR4 substrate to a 50 watt amplifier at 1.7GHz. I deem or not it’s attention-grabbing to gaze what branches of the array had burnt. With this photograph every person is seeing how these antennas work and that are the aspects that are feeble for a given frequency. In a log periodic plan simplest a few aspects make a contribution accomplish as it will be clearly considered.
Thank you, Bernd!
July 2019: We fancy attending IMS, and we remove to meet with our chums and fans. And or not it’s sizable that some suppliers provide free beer on the exhibit floor, as long as every person remembers to be cautious. Here’s an image of an accident at a sales space that will seemingly had been prevented. Pro tip: procure not preserve close you need to say the phrase desk-high as a jam to jam your beer when you fawn over the sample hardware…
October 2018: This characterize came in from Dave, and we admit, it took us a minute to get dangle of the difficulty. Ogle closely – are you able to gaze where they went corrupt?
September 2018: From “Nameless”, that is a photograph of the clean room at an unnamed facility…ick.
Here’s a submission from David, who got this from a buyer for calibration. We’re not obvious calibrating will repair that needle!
Unusual for Could fair 2018: From Tom. Why is it soldered this vogue?
Unusual for April 2018: This came from Dave, title is “Coax Dielectric Loss”.
Positioned say at roughly 263 toes…opened the line 9 sections up from the imperfect of the tower and confirmed that this changed into once the positioning of the failure. It changed into once valuable to scrub six transmission line sections above the failure due to contaminants from the burned Teflon. 9 transmission line sections below the failure had been also cleaned due to the the soot contaminants from the burn.
All the arrangement throughout the cleaning the crew stumbled on a sad and charred ty-rap within the transmission line above the failure level. We suspect that the distinctive failure changed into once due to the a ty-rap that has now been thoroughly burned up. There changed into once no injury to the inner conductor or the growth joint and the finest level of failure changed into once a smash down of the Teflon insulator. The insulator wanted to be depraved with some foreign object or field subject in say to breakdown and burn as is on this case.
One other ty-rap changed into once stumbled on roughly three transmission line sections below the failure level.
Editor’s easy: trusty because something is white and plastic, does not mean it has very ample microwave properties fancy Teflon. If a ty-wrap has uncomfortable loss tangent and is exposed to high electrical field strength, it will heat up and in the end burn. Foreign object/debris (FOD) is a trusty say in manufacturing hand and asserting hardware.
Replace from Tom
Here’s what the final amps explore fancy inner:
Unusual for December 2017: Some concerns with a high-energy combiner, from Tom…
So is this Wilkinson or Wontkinson*?
Here is a 2500 watt FM broadcast band setup from a producer of very uncomfortable and smartly deserved reputation. The greater unit is the exciter, which is a mixed exciter and 150 watt PA unit. In fashioned operation it runs about 45 watts which goes to the power divider in the heart unit, which divides it out at 0 levels to every amplifier. These feed a Wilkinson combiner, which sends energy to the final output. Each amplifier is 500 watts output. Keep in mind this for later.
Sounds piquant, piquant? Brace your self.
The ability divider is full poppycock. I’ve by no arrangement considered anything else fancy it, and it does not work smartly — a few watts replicate reduction to the exciter. But then you definately hit the Wilkinson and the quarter wave transformers fabricated from coax cable. Very very thin coax. I overlook what the section number is but the heart conductor is potentially 28 gauge. For 500 watts.
So now, the resistors. Their goal is to dissipate energy and provide isolation in the event of a mismatch, which mustn’t be sustained on the total for the reason that amplifier must ideally decide up some safety aspects that will trigger foldback or shutdown in the event of mismatch.
This one has none.
The amps procure not decide up ANY interlocks or unified energy reduction watch over in any admire, and merely switching one of the amps off with the plan operating will thus trigger meltdown. The resistors could seemingly’t handle a important mismatch dissipating the pudgy energy of an amp. I procure not know which amp(s?) went down first but I got the message the signal changed into once “unlistenable”. As I drove to the positioning I heard a tainted chunking noise pudgy of 60 cycle ac growl. It sounded fancy the transmitter changed into once occurring a rubbish disposal…. Which wouldn’t be some distance from what no doubt took place. Three of the five amps seem to make a decision on up blown up and the combiner is WELL DONE, it even melted the fan partially.
It’ll be self explanatory which photographs are ahead of and after. The copper plate grew to change into blue!!
These photos attain from Jose. Editor’s easy… Jose just will not be by myself in the GaN-blows-up-when-you-explore-at-it-silly skills. Ship by yourself non-ITAR/non-proprietary failure photographs please!
In the midst of of making an are trying out some GaN PAs we ended up blowing up one of them, and the blown up transistor is so beautiful that I felt compelled to portion it with the sphere. Temporary story in the aid of it, we valuable to enact some measurements with out the say of off-chip capacitors and this unstable PA ended up drawing too valuable recent. Surprisingly it peaceable had accomplish after being left with one much less transistor.
Attributable to of Zach:
I’m hoping this iphone charging brick suits the hardware graveyard, my girlfriend’s sister had an extension cord next to her closet and one arrangement or the opposite a metal garments hanger got in between the outlet and the prongs and tripped the breaker fortunately but not with out doing a small bit injury…
By the vogue, that is precisely the goal that grounded shops are no doubt mounted with the bottom on high (gaze here). Too inferior cell phone chargers must be made so cheaply they leave off the safety ground…
Unusual fro July 2017: here’s a standard needle probe wreck from Robert. Thanks! Here is a DC probe, with integrated bypass capacitors feeble to stabilize amplifiers once they’re RF rested on-wafer. Imagine it or not, this vogue of accident will seemingly be repaired, both by a affected person technician, or by returning it to the producer.
This cautionary story came from Darrell.
Here is an Anritsu 2.92 mm airline from Ebay. The female discontinue changed into once stuck between the wall and center pin of the tip cap (short circuit) when it arrived. Or not it’s going reduction for a compensation. Ebay for anything else with microwave connectors looks fancy gambling. I’ve sent reduction about 25%.
Also from Tom, titled “C-band by the Sea”. The distinctive characterize are very high-res, sadly they’re too mountainous to upload…. we are going to figure it out and add them later.
This C-band satellite feed horn and polarotor lived by the sea. Are you able to characterize?
Hyperlink margin and EB/N0 trusty step by step shrank away to Davy Jones Locker.
Unusual for January 2017: from Jacob, in two installments:
This week I bought twenty surplus Nokia RRIC boards. After I bought them, it changed into once very obvious the warranty changed into once void… I bought the board very low-price, primarily for salvaging the N-connectors for ham radio say. And there are some tremendous other parts fancy a lot of xtal oscillators and smd chips for working in the direction of my smd soldering skills. I knew the location of the board after I bought them and for the phrase I could seemingly seemingly not complain. But I questioned what took place to the board ahead of I bought them… Are they been paddle over by a truck?! Now not simplest parts are lacking/prick up in half of, but parts of the pcb are cracked and even lacking, including half of of the connector!
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