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August 11th 04, 12:31 PM

On 11 Aug 2004 03:25:21 GMT, (Len Over 21) wrote:

snip

BTW, you mentioned in an earlier post that you have a Patent
registered to you, in the area od radio. Interesting - mind if I ask
what it was?

U.S. # 3,848,191 - Pulse Compression Receiver with AGC, granted
in 1974, assigned to RCA Corporation. Sole inventor on patent.
Missed two other applications due to being too close to prior art.

Basically it is a pulse processor and operating in an environment
of many different pulses, only a few of which come close to being
in synchronism with the system. The application was for SECANT,
an R&D project for 4 years at RCA, the acronym standing for
SEparation and Control of Aircraft by Non-synchronous Techniques.
SECANT was an aircraft collision avoidance system and in direct
R&D competition with a modified helicopter station-keeping system
done by Minneapolis-Honeywell. Both the RCA and Minnie-Honey
systems were flight-tested successfully in PA at the (former) Naval
Air Development Center (NADC). Flight testing local in PA, at the
Patuxent River range, and at Key West, Florida, observed by FAA
troops locally as well as USN and USA people. First air tested at
Kern County Airport #7, Mojave, CA...("Mojave International" in fun)
now the site for Scaled Composites, the first company to make it
into space privately.

SECANT worked at 1.6 GHz nominal bandcenter. The final version
(of three) in 1974 used 8 SAW (Surface Acoustic Wave) matched
bandpass filters done on quartz substrates (done at Sommerville,
NJ) at 1 MHz bandwidths centered between 55 and 64 MHz. I got
to play with the SAW filters and the final version IF-detectors plus
the pulse pre-processor. Al Walston, W6MJN, and I shared
responsibility for the Tx and Rx parts. Jim Hall, KD6JG, was the
engineering technical manager over the last two versions of
SECANT and all of RIHANS, another R&D program, again working
in L-band at the RF level.

The U.S. government scuttled any more testing funding in 1974 for
both the RCA and Minnie-Honey systems, opting for a less-tested
ATC transponder modification which is now in use, but only by the
air carriers and large executive aircraft.

TCAS? (now TCAS II)

Military doesn't use that
system. MIT had friends in higher places to sway gubmint opinion.

RCA Corporation began (well before WW2) as a place to hold
U.S. patents and try to keep control on the then-new technology
of radio. As a result, RCA built up a fantastic legal staff and pursued
patent filings aggressively. Back in '74 the average cost of any
electronic patent application cost about $6000, nearly all of it being
taken up by the non-patent-office Search costs. Corporate
employees of the lower levels would not get much chance to patent
anything unless a corporation had a large legal staff. I was lucky in
getting a sole patent award and don't sweat the other two at RCA
nor the one multiple-inventor patent turn-down at Electro-Optical
Systems (Xerox division). [sometimes good minds think alike! :-)]

Very impressive - thanks for the summary. I'd never heard of the
SECANT system before.

That would have been quite a challenge back in '74 - all discrete
components, no microprocessors, no CAD tools or circuit
emulators....real hands-on design work.

No wonder you're getting so much heat here, Len - clearly, you are out
of your league. Are you aware that there are folks here who have
successfully assembled their own Elecraft kits, and built working CW
transmitters from plans? :-) :-) :-)