Microwave Mortuary

Updated April 2, 2013

Have you ever thrown a shopping cart out of a convertible at 80 mph to observe the sparks? How about hooking up a power amplifier to 115 volts AC just to see how it craters? Your fellow engineers have done these things and more! If you have a great picture of totally destroyed hardware, or a photo of a blown circuit, send it to webmaster@microwaves101. If it gets on the web site you will receive a free Microwaves101 key chain pocket knife! Impress your friends, if not your boss!

New for January 2013: the mortuary has now been separated by year, as we have had a few complaints about how long it takes to load. But maybe it is time some of you considered a better broadband connection to the internet?

Here are links to our archived Mortuary pages:

2011 Mortuary

2010 Mortuary

2009 Mortuary

2008 Mortuary

2007 Mortuary

2006 Mortuary

2005 Mortuary

2004 Mortuary

Note to mortuary contributors: please consider that your boss may not find your submission in the best interests of your Big Company. Lately we've been getting a lot of "please remove my submission" emails, try not to send us anything that you might regret.

Note to Big Companies: Don't blame us for posting your spectacular failures, we only post what your employees send us. On the other hand, please don't rip off Microwaves101 pictures for presentations without permission, that's bad manners. Maybe it's time for some training!

Note to mortuary fans: In many cases, if you click on pictures on this page you can see higher resolution images.

New for April 2013: These photos came from Dave:

Here is an interesting item.  From a High Power HV SMPS, that is part of an old Varian TWTA.  One of the noisy types that scream at some 4 kHz....   200W out CW, 2 to 4 GHz, one of the "old school" types.

SnubberFail-1, the overall view of the board after we removed it from the amp.   Even more spectacular when you realise that the amp was still usable in that state!   We were told that it "just made a pop" but carried on working.  The customer only took the lid off to look, after finishing some testing.

That board is the main Switching Regulator card that in turn feeds the inverter that (literally) whistles up the HV.  It's fed from raw rectified 230VAC.  (No such thing as PFC when that was built!)

What's not shown, is the mass of resistor wire that spilled out of the exploded resistor, that in turn was entangled around all sorts of stuff, while still connected to the raw DC etc.   I guess it's insulated, as there were no shorts or other explosions.   No fuses were harmed either!

I apologise for not reacting in time and getting a picture of that mess, but even so, it's remarkable this unit survived relatively unscathed, and carried on working after the "Pop" (they say...)

SnubberFail-R and -C are closeups (as much as a phone-camera will allow) showing the result in detail.

The cap is (was) a 10,000pF 500V Silvered Mica part.  What caused it to fail we don't know, that and with all the other high power RF and switching stuff we deal with, we've never seen a Mica cap fail like that before.  Or for that matter, one of the aluminium clad resistors explode...

After stripping many parts from the board, giving it a good scrape wash and brush up, refitting the removed (good) parts back in their original positions, plus a new resistor and Silvered Mica cap, normal service was restored (we went through the recommission after repair procedure, but found no issues) resulting in a happy customer to boot, who were bracing themselves for a rather large replacement amplifier bill.  Not that with the time involved for all the above, it was a low cost fix, but much lower than the replacement cost of the entire unit.

After that, they then brought us (the day they collected the Varian) an old Logimetrics Pulse RF TWTA, that wouldn't do more than about 2% duty.  (It was spec'd to at least 40%)  We found a failed resistor in a medium power stage that caused the Grid drive to fail when pulsed beyond a low%, tripping the HV as a result.   Another old but high value bit of kit saved from the skip.   What they will bring us next, who knows...

(Click on images to view close up)

New for February 2013: This photo or the spectacular 2011 television tower fire and collapse in Hoogersmilde came from Ivo:

Today I had a look at your Microwave Mortuary pages….fantastic!! It remind me of what happened here in The Netherlands at July 15th, 2011. A local 300 meter TV-tower collapsed due to a fire in the tower. You can find more info (sorry; in Dutch) on: http://fmtvdx.eu/zendmast/smilde/hoogersmilde.html   This is a good chance for you to try out Google's translator, check it out! be sure to click the links at the bottom of the page to see a zillion high-res images of the carnage, plus videos. Also, this is a appropriate time for us to review the story of Hans Brinker, although it is more of piece of American culture rather than Dutch, they did create an awesome and inspirational statue of the boy and the hole in the dike to remind us all of what we do every day at work- UE

New for February 2013: these photos came from Tom, we'll let him tell the story. But let's first point out first that Teddy bears in museums deserve more respect, especially Misiu. And the movie Ted should win Best Picture for 2012 in our opinion.

Here at our facility, visited by thousands of happy children and their families every week, we have a pool with four Tornado remote controlled boats (not the Tornado corporation that makes rigid inflatable boats for people to ride in, but the one that makes amusement park interactives!) Anyway, over the past nine years of operation, at times the Tornado boats like to prove the old adage that electricity and water do not mix.

Over time the 12 volt DC power to the motors (which are beautiful Swiss made Maxon DC brush type and survive insane high mileage) simply made the traces Go Away.

Also, you will find attached the control board from a "ClearVue" condensate pump, on which the pump's holding tank apparently overflows right into the control board the first time it has trouble keeping itself drained, a karaoke booth that got a morocca through its monitor, and what some of our guests did to a giant teddy bear.

The one of the broken ELO Touchsystems monitor is curious and haunts me to this day. I still stay up at night sometimes wondering what possessed this one fifth grader on a class trip to decide to interact with the karaoke booth menus by smashing the Surface Acoustic Wave touch sensing glass with a morocca. I even nicely asked the child after the fact but he was inconsolably crying and could not get a word out. It will be a mystery forever.

New for December 2012: these photos came from Kerry:

Ran across this on ebay; Airborne radar receiver I think. This seller is an optimist given the starting price of $200; he also has the subtle gift of understatement; “Item looks in non-working condition. Can't test it.  Sold as is.”.

New for August 2012: These fine photos came from Nicola, from Italy. and sat on our email in-box for several months (sorry!)

File 0 is taken from one of the two sides of a 2KW LDMOS UHF amplifier: as you can see, all the 250W class AB modules inside have burned their hybrid output coupler, for unknown reason.

File 1 is taken from a site in a very windy location: as you can see, wind stole the dish from the mounting brackets.

File 2 is... the dish found somewhere around there.

File 3 and File 4 are the same situation of above, in the same location: the parabolic antenna was attached at the corner of the building because we were not able to find satellite from the lattice tower: there was another tower just opposite the dish.

File 5 is a very old tube linear amplifier, found in a site before installing our systems.

File 6 is an inner damage of a rigid transmission line in a 2KW UHF amplifier: from the right, the line damaged, the coaxial cable of that line, and the new part

File 7 is a very annoying obstacle met in the street trying to reach our broadcasting site

File 8 are damaged antennas because of ice blocks fallen from the lattice tower.

New for July 2012: from Chris:

Attached are three pics for your microwave mortuary.  One morning while making a cup of coffee I saw a lightning bolt hit my backyard near a flock of turkeys.  I learned turkeys really can fly, but didn't think anymore about the strike until I went to get a tool from the shed and found my invisible dog fence controller blown across the room.  The lightning bolt did strike in the vicinity of the buried wire and apparently imparted enough energy to vaporize something within the controller, but what?  The damage clearly originates at the terminals for the buried loop antenna.  The MOV was never installed (no leads poking through on the back side of the PWB).  The teardrop shaped hole was for a case standoff.  My guess is that enough energy was input at the loop antenna to vaporize plastic and circuit board/resist so rapidly as to jet propel the controller across the room.  I've blown stuff up real good before, but nothing beats what mother nature can do.

Also new for July 2012, from Cliff:

The attached picture is the security ECU from a Porsche Boxster.

I live in a quaint English village with a central green and duck pond. Most of the residents here park their cars alongside the pond. Unfortunately about once every 5 years England has some sort of deluge rain storm which leads to the river that fills the pond being overwhelmed with floodwater and as the pond has a sluice gate at one end it acts as a natural dam to any floodwater that comes downstream. Rather sadly I happened to have parked my Boxster right next to the pond last time this flood happened. It was totally unexpected overnight or I wouldn't have been fool enough to park the car there. The first I heard was rather bleary eyed at about 06:00 the following morning when I could here a car alarm going off and then a sudden realisation that it was MY car alarm. Unfortunately the alarm only triggered as the car was in the latter stages of dying and the security ECU is positioned in a well beneath the passenger seat of the car so once the water reached it it not only triggered the alarm but completely immobilised the car so it had to be pushed out of the water. It sat for about a week in the hopes that it "might just dry out" (I didn't know the ECU was waterlogged at this stage) but when it still would not start it was then towed away to a garage who were astonished to find the ECU in the condition seen in this photo. Needless to say Porsche replacement parts are not cheap!

New for June 2012: this came from Reid:

I am a master's student who recently learned a fun lesson in checking part numbers.  I am working on a VHF power amplifier. I received a power amplifier pallet from a trusted source and promptly hooked everything up to test it out.  After having a metal clad SMT capacitor explode in my face (twice), I took the case off of the transistor to see if it was blown a long with the capacitor.  After removing the top casing I realized that this transistor did not look like the others I had opened of the same part.  I found the pieces of the case and found, in fact, it was not the part I thought it was.  Attached is a picture of a  blown UHF 1KW pulsed transistor.   Long story short, always check the part numbers to make sure the manufacturer put it together correctly!

New for May 2012: these came from "Ed 2":

Here are some images of the inside of a weather radar radome that suffered a direct lightning strike.  Two of the images show pieces of fiberglass and gelcoat that were blown off of the panels onto the floor.

New for May 2012: This came from George. Check out how "amplifier" is spelled in Japanese...

While looking through my radio shit/radio humor folder, I found this. No, it's not RF per say, but it is the real data plate on the back of a Sherwood quadraphonic amplifier that I purchased for $20 at a hamfest a few years ago. Despite its dubious nomenclature, it does work well - after I blew the cobwebs out of it and chased the cold-solder demons out of one of the left channel outputs. Enjoy.

New for April 2012. From Ed, his second contribution on failed rotary joints, which makes a great argument for AESAs...

Here are a couple of pictures of an X-band rotary joint that failed and caused the WR112 waveguide connected to it to twist at least two times.

New for March 2012: these came from Chris:

These seem pretty much self-explanatory; the birds are Long Billed Corellas (aka the juvenile delinquents of the bird kingdom), which come in flocks of anything up to a couple of thousand. You can imagine the chaos when they descend on an antenna farm, or even a household TV antenna.

I suppose you have to admire the neat way they have stripped the coax…...

Also new for March 2012: these came from David:

The fried board comes from a 1kW HF transmitter. One of the capacitors had overheated during an experiment, burnt out and taken the board with it. There was also a generous amount of conductive carbon deposits spread around.

The other photographs are of the remains of a protective coaxial spark gap which protected another 10kW HF installation from a nearby lightning strike. The flashover welded one end of the removable spark discharge capsule (about 1cm diameter & 1cm long) to the centre of the coaxial housing as a blob, damaged the outer casing and loosened the central conductor. The rest of the removable spark discharge capsule had been reduced to fragments and hadn't been saved for photography.