When Cardion Electronics was first organized in late 1960, the first president was Orville M. Dunning. He had an illustrious history including work at Hazeltine and also AIL, Airborne InstrumentLaboratories. His background included both an engineering background and a patent law background as well. Coincidental to all this he was a widely respected amateur ornithologist (birdwatcher) and friends with a Dr. Lanyon, Chief Ornithologist of the American Museum of Natural History.
Apparently in chance conversation, the question of how fast birds could fly in various surroundings came into discussion. Bear in mind that these discussions took place inthe very late '50s and stretched into 1960 when the Cardion idea took form. The use of CW radar to measure speed was relatively well know but no one had considered its use to measure the speed of flight for birds. Dr. Lanyon had very little money, only $1800 as I recall, but we didn't have crushing business so we set out to design a CW radar for the American Museum of Natural History.
This time frame was late 1961 and the stores along Canal Street were chock full of so called "war surplus" of every manner and means thinkable. So from flier sheets it was possible to locate spun lightweight aluminum parabolic reflector about 15 inches in diameter complete with an X-band waveguide antenna feed. These units were apparently production run surplus from the company fabricating the antenna and feeds for some prime contractor. Apparently they were part of an airborne radar. They suited our purposes perfectly.
If you look at the classic CW radar, it used 2 such antennas; one for transmission and a second for the receiver. These two antennas of course have to be aimed so that their respective axes are parallel so that they see the same volume in their respective beams. Radar types refer to this as collimating
their beams. To assure this mechanical alignment the antennas are best mounted on a stiff beam support and then this assembly turned and tilted to aim the antenna(s) beam.
This beam support was fabricated from two so called "Budd boxes", each 7" x 11" with a flat sheet metal cover on the open side. The boxes were 7" deep. Two of these boxes were joined at the end providing a transmitter enclosure and a receiver enclosure with the metal covers on the back side away from the
antennas. The antennas were respectively mounted to the far wall of the boxes and positioned so that the edges of the parabolic reflectors just touched.
If one consults the first edition of "Introduction to Radar Systems" by Merrill Skolnik, turn to page 1, chapter 1, in Fig.1.1 there is a block diagram of an elementary form of radar. This accurately describes the FTB-1. On page 3, equation 1.3, shows the equation that relates the tone frequency to the target
radial speed.
The transmitter source we used was a Varian VR153, reflex klystron, which put out about 250 milliwatts and was adjusted to 9375 mhz frequency. The doppler tone constant then was 27.947 Hz per mph radial speed. So to measure the radial speed of a bird, you had to (1) keep the antenna(s) beam pointed towards the bird and (2) measure the frequency of the doppler tone. The aiming part was aided by an inverted "T" rail attached to the topside of the box support. The unit was modified so that the center of the box support would mount directly to camera tripod. Using a good quality pan-tilt head the unit could be maneuvered and aimed easily. Two meter displays were provided, one displaying the frequency of the doppler tone and the second was used to monitor critical and essential voltages and currents to
assure proper operation. Initially the full scale reading of the speed meter was single scale set at 50 mph maximum. After some use, this was changed to a multi-scale reading of 0-25. 0-50, 0-100 mph. In addition provision was made via phone jacks so the tone could be recorded on a magnetic tape recorder for subsequent playback and further analysis. This further analysis showed some very interesting and previously unknown flight characteristics of certain bird species. Just what Dr. Lanyon wanted for his students.
The prime power source for the FTB-1 was a 6-volt car battery. Actually we made up a Nicad pack intended for short term operation which worked quite well but provided only about 1 hour combined operation/standby. The car battery allowed them to set up in a blind and go on standby for the entire day and still have enough power to record all they wanted.
The electronic guts of the unit were straightforward. In this time frame the so-called DC-DC converter was all the rage allowing 6 volts input and multiple output voltages. In the case of the VR-153 we needed 6.3 vdc for the filament (remember those?), +250 vdc for the anode and -150 vdc for the reflector.
This DC-DC converter was located within the transmitter box. A separate DC-DC converter was provided for the receiver and located in the receiver box. In this manner we provided quite effective shielding between the two systems. The shielding was important because the amplifier following the receiver crystal detector had sufficient gain to be noise limited.
Operational experience
After we had assembled the unit we played with it a while in the parking area behind the plant using targets of opportunity. We quickly determined that it performed quite well against cars, people on bicycles, and even airplanes overhead approaching JFK. Interesting thing about CW radars is that they
will work at some range on almost any target; question is, is that range useful for the intended problem. So we were confident that we could detect birds at some range but we just didn't know how far. That remained for Dr. Lanyon and his students to determine.
They did indeed use the unit and quickly learned the routines to provide optimum siting of the unit for best performance. Eventually they worked mostly from a flat-bottomed boat with camouflage applied so that they could approach water fowl quite closely. Using the tape recording and playing the audio through an audio spectrograph they were able to determine and measure the wing beating patterns. One unusual thing previously unknown was that a frightened black duck could fly up to 95 mph and his wing beat pattern was 4 beats followed by a pause, then 5 beats followed by a pause, then 4 beats etc. Never
heard any explanation why the 4, pause, 5, pause pattern. But it was fairly consistent but unique to that species.
The FTB-1 had sufficient sensitivity that large birds could be tracked while flying overhead but now the speed reading had to be corrected by the upwards aiming angle of the radar unit. The pan-tilt head had a protractor scale to show the angle. So the students had to use a little trig to correct the speed reading.
I am not sure how many students actually used or participated in using the FTB-1, but after about a year to 18 months, I received a phone call asking if we could rehab the unit. I, of course, said Okay and expected to see the unit come back needing some checking over and rehab. NOT THE CASE! Seems
what had happened was the boat capsized and the FTB-1 got dunked in a few feet of salt water. That's the bad news. The good news was the car battery connection was broken so the unit was not powered at all while submerged. Now for some more bad news. The students thought by washing it thoroughly with fresh water and drying it out they could apply power and hopefully the unit would work again. Now for some more bad news. Didn't work. The component boards were NOT coated and the corrosion was
horrendous. So that was when they decided to call and brought it back.
We completely rebuilt the unit and COATED the boards this time. We had found a better crystal for the receiver improving the sensitivity and gave the outside a nice protective paint coating. In the intervening time since the original unit left the plant we had hired many more people and the usual question was, "Who the hell made this thing?" When someone who knew answered, "We did," the usual response was "No sh_t".
Epilogue
Now for the last detail. How did the nomenclature FTB-1 come about? At that time (early '60s), a favorite slang negative expression was, "That's for the birds". We had a tiny company newspaper and in the article we said that the radar was literally, "For the birds", hence FTB-1.
Dr. Merrill Skolnik, a very reputable radar guru gives a lecture periodically on the subject of "Unusual Uses of Radar". He called and asked if it was Okay to reference the FTB-1. I said fine and provided with as much technical info as I could.
So that's how the FTB-1 came to be.
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