IEEE Consultants' Network of Long Island

The Sculptor - John Dunn, Consultant, Ambertec, P.E., P.C.

The company had hired an engineer for a microwave project and the fellow dug into the work with energy and gusto. He seemed genuinely happy, until......

The planned design was going to need some stripline structures, but an examination of several circuit boards convinced this engineer that the available geometric precision of circuit board artwork at that company was inadequate for the purpose at hand. Therefore, he brought in from home an utterly exquisite set of precision carving knives and working by hand, he actually carved the required stripline structures out of raw copperclad circuit boards without ever etching them.

His stripline carvings were wonders to behold. Engineer after engineer, upon seeing them, walked away awestruck.

THE FTB-1 (For The Birds) Radar--Carl Schwab

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.

Weather Radar –What makes it work?

Almost without fail, if you look a local TV newscast likely somewhere they will
introduce a forecast, usually a 3 day, and imbedded will be a radar/satellite rain cover in
compressed-time format for the last 2-4 hours. How does this work?

The foundation equation upon which radar detection and measurement of weather
phenomena is –

   S=PI^5 x D^6/w^4 x K^2
Where:
PI=3.1416
D= droplet diameter, cm
W= wavelength, cm:
K= approx 0.93 for water; 0.197 for ice, 0.0 for air
S is in cm^2

This equation applies for spherical reflectors. K varies as a result of difference in
dielectric constant, e. For water it's about 90! For ice it's about 4 and of course for air it's
1. The weather radar receiver instantaneously sums S over the resolution volume of the
pulse packet. This summed signal is defined as Z, and its value Z-factor.

   Z=200 x r^1.6
   Where r is mm/hr rainfall rate.