Month: March 2018

Breaking Things

Tom Gregory recently emailed some photos to me that he took in the ’60s while he was a student at Ravenna High School. These pictures brought back memories of the following events:

When Spohn’s TV Repair Shop in Ravenna closed and went out of business, the owner contacted me and asked if I would like to have the remaining stock of old TV’s and various electronic parts for use at the school. He informed me that there was about a truckload of stuff and I had to take it all. When he said a truckload he wasn’t kidding. The stuff completely filled my flat bed truck. There was everything from TVs in various stages of dis-repair to vacuum tubes, capacitors, resistors, knobs, wires, nuts, bolts and screws, along with things I didn’t recognize. This was an experimenter’s dream!

This stuff filled one corner of the physics lab. One problem that immediately needed to be addressed was that some of the TVs didn’t have a cabinet and the picture tubes were exposed. This needed to be taken care of for two reasons:

1) A picture tube acts like a large capacitor and can hold a lethal charge of electricity for a very long time.

2) If broken, the tube’s high vacuum will make it implode and go off like a bomb, causing glass shards to be violently thrown around the area – not a good thing to have in a school full of ornery kids..

So the first thing I did was remove the picture tubes from the TVs that were not to be repaired.

We repaired the remaining TVs, then sold them and used the money to buy lab equipment. Others were torn apart and the parts used for various projects. The power transformers and rectifiers were used to power radio gear and for power supplies in the lab. We also built some 6 volt power supplies as battery replacements for Mike Lenzo’s 6th grade science classes.

Now I had to decide what to do with those potentially dangerous picture tubes. I couldn’t just throw them away because they had so many interesting possibilities.

Tom Gregory was one of the students who first got me interested in ham radio. He was also the school photographer and an electronics experimenter. One day Tom showed me his recent project – a device that would allow sound to fire a strobe light. With it he could take a photo simply by clapping his hands.

When I saw this device my evil mind went into high gear. Why couldn’t we use this to take a high-speed action shot of a TV picture tube imploding? The sound of the implosion should set off the strobe light and cause the picture to be taken.

There were several problems to overcome. How and where could we safely do this, and how could we do it without sending the instigators (us) to the hospital? We consulted with “Otch” Houston, the chemistry teacher, who was also interested in this project.

Otch had recently built a new house with a large and almost empty basement. We decided that this would be the perfect place to conduct our experiment. I didn’t think his lovely wife, Dianne, would let some weirdos blow up stuff in her new house, but we convinced her that this was in the interest of science and the future of mankind, and we would clean up any mess we made and fix anything we broke, so to my surprise she foolishly consented.

We hung a pulley on the basement ceiling with a rope running through it. On one end of the rope we tied a large brick, the other end we strung behind a barrier where we could all hide and be shielded from the flying shrapnel. We then put a picture tube below the pulley where the brick would fall. Tom set his camera on a tripod, turned on the strobe device, turned off the lights and opened the camera’s stutter. We then crouched behind the barrier, hoisted the brick up to the ceiling, and let ‘er fall.

The resulting implosion was much more violent than we had expected- sounding as if a shotgun had been fired. It threw pieces of glass all over the basement, some as far as 40 feet. The size of the razor-sharp shards ranged from palm-size down to grains of sand.

We were so shocked at the violence of the implosion that we started talking and laughing excitedly – each of these sounds was repeatedly setting off the strobe. This cut down on the picture quality since the shutter was still open. More problems occurred when we walked over to close the shutter – each step crunched the broken glass, again triggering the strobe. To solve these problems we re-adjusted the sensitivity of the trigger device and restrained our laughter until after the shutter was closed.

The results of our efforts are displayed below. I hung these pictures on the bulletin board at school to show the students what a dangerous device they had in their living rooms, and to convince them that a television set needed to be treated with care.

This one had previously lost its vacuum and merely broke apart

These imploded violently 

Clean-up time

Tom, Otch, Gene – The Instigators

(Also read Tom’s comments below)

MARS

While conversing with some of my amateur radio friends I learned about a group of hams who were attached to the military. This group was called “The Military Affiliate Radio System”, or “MARS” for short. Members were trained to help the military in emergencies. Much of their time was devoted to providing communications between soldiers on active duty and their families. This was before satellite phones and the internet, and by ordinary means these communications were often slow and difficult . The MARS system made these contacts more efficient and almost instantaneous. This appeared to me to be a worthwhile endeavor since our country was in the middle of the Vietnam war, so I joined MARS.

After some training I became very proficient in Morse code and was put in charge (net control) of the Sunday night MARS CW (Morse code) net. Message traffic was passed from Vietnam by the military to state-side MARS members. Any of us who lived close to the receiving family would accept the message, translate it to regular English, and forward it to the appropriate person by phone or letter. We could also communicate in the other direction- from civilian to military.

Some MARS members provided “phone patches” so that soldiers could talk to their families in real time.

At that time MARS was the quickest way that messages could be passed between members of the military and civilians.

As a reward for providing this service the MARS member received outdated surplus military equipment that could be modified to use for his radio hobby. Through this program I received much of the equipment that I used for my radio station, along with some that was used at the Ravenna High School radio club and and in the physics lab. My students and I rebuilt several transmitters and receivers that we used in the school radio station.

Collins AN-ART-13 auto-tune transmitter used in WWII bombers. I used one  in my amateur radio station.

Hammarlund BC779 Super Pro. These were used onboard ships by the Navy  and when modified worked well as short-wave receivers.

The most fascinating things I received from MARS were Teletype machines. These beasts consisted of an amazing array of levers, gears, motors and springs, and just sat there and typed all by themselves without any apparent human intervention.

Model 19 Teletype

I built an interface that connected a Teletype machine to my Super Pro receiver. This combination interpreted two timed audio tones, 850 cycles apart, that were sent by the transmitting station, and turned these into typed messages. This seemed like absolute magic! When the cover of the machine was removed, it revealed a whole bunch of stuff in motion that magically typed out messages on a roll of paper!

The “Innards”

When I received my first Teletype machine I hooked it up to my receiver, tuned it to the MARS Teletype station at the Pentagon, and began to make adjustments. All of a sudden it started typing:

” WAR WAR WAR WAR WAR WAR “

I didn’t know whether to run or to get under the bed!

It turns out that the MARS station in the Pentagon had the call letters “WAR” and the machine was acknowledging that I was receiving them. WHEW!

The highlight of my MARS career was when I was chosen (twice!) as an operator of the CW station at the Pentagon in Washington, DC, on Armed Forces Day. MARS celebrated this day with a military to amateur crossband communications test and a message-receiving test. These tests gave amateur radio operators an opportunity to demonstrate their individual technical skills. On this day hams from all over the world tried to contact the Pentagon. If successful they received a QSL card from the Pentagon MARS station.

A QSL card is a fancy postcard acknowledging the fact that your station made contact with another station, naming the call sign, country of origin, signal report, and other comments. These are proudly collected by hams showing the different countries that were contacted. Most ham stations have their walls covered with QSL cards from all over the world. Getting one from the Pentagon on Armed Forces day was a coveted honor.

QSL Cards

When operating this station on Armed Forces Day, I was the most sought after person in the ham radio world.

I would send an invitation in Morse code that went something like this:

“CQ CQ CQ de WAR WAR WAR        K “

Then listen – and try to untangle the swarm of replies, all jumbled up, sounding like a bunch of mad hornets were after me.

I would answer the strongest signal with a signal report – RST 599 or whatever, and log the event so that the Pentagon could send this guy his QSL card. He might give his QTH (location), but there was no time for chit-chat since there were too many people waiting in line. I would terminate this message and try to identify another caller. When the racket subsided I would send another “CQ” and the process would start all over. This went on all day, and I made literally hundreds of contacts. Needless to say my head was full of dots and dashes for the next week or so.

Gene at the Pentagon MARS station

MARS is still active today. It is now called The Military *Auxiliary* Radio System. Morale and welfare messages are no longer the largest activity in MARS due to the increased use of the Internet and e-mail by deployed military personnel. Its primary mission now is to provide contingency communications to the Department of Defense and Military Services. It is also available to assist state and local emergency response agencies.