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Re: [TowerTalk] the elusive 1db

To: "'Bob Nielsen'" <>,"'TowerTalk List'" <>
Subject: Re: [TowerTalk] the elusive 1db
From: "Wes Attaway (N5WA)" <>
Date: Tue, 15 May 2007 21:17:37 -0500
List-post: <>
That is a real interesting observation about that dish.  I had
some experience at Michigan State back in 1962-63 writing some
Fortran programs and using IBM punched cards.  I never saw the
computer. In fact, I didn't really know much about how the
computer worked.  I just wrote some code, punched the cards, and
put them into a steel drawer.  The next day I would come back and
see if the white-coated computer priests had given me a printout.
It was touch and go, but finally I got some actual results.

My guess is that someone actually did the math for the dish and
wrote a program and ran it on a mainframe and came up with the
design.  It could be done .... it just took a little longer back
then.  But even then the computer was a lot faster than a slide
rule, and a whole lot more accurate.  Slide rules were great, but
you were lucky to get within 10 per cent if there were very many
calculations to make.

-----Original Message-----
[] On Behalf Of Bob
Sent: Tuesday, May 15, 2007 8:25 PM
To: TowerTalk List
Subject: Re: [TowerTalk] the elusive 1db

On May 15, 2007, at 3:02 PM, Pat Barthelow wrote:

> That elusive DB just reared it head at Jamesburg.  We
> that our
> dish has neither parabolas, or hyperbolas as part of normal
> surfaces.  Mike Brenner, our laser metrologist just determined
> the
> dish, built by Philco Ford in Late 60s, probably designed in
> 60s was a
> tweaked design that had reshaped both surfaces to gain only
about 1  
> db more
> in the 63 dbi gain dish.
> I dont know why they went to all the trouble to do that to just
> one more
> DB to listen to Geosynchronous Satellites.
> But a more interesting question, in light of the fact that this
> before  the HP 35 was around , (;>)  in fact in the REAL olden
> Engineers used slide rules, and surveyors used 8 place trig and

> Logarithm
> tables.   Logsin A minus Logtan B plus...oops...
> Anyone here from that era who might know if such a dish
required the
> computation horsepower of a mainframe of the time, to design
> build?
> Say a bunch of Fortran Punch Cards and an IBM 360?

Maybe a bunch of grunts wielding Friden or Marchant calculators?

I worked at Douglas Aircraft for a brief time in 1957 before
going to  
college.  My job title was "technical computer" and I had a nice
noisy Friden mechanical calculator on my desk to use in
flight test data for the Navy A4 jet (which I had read from 35 mm

film, their being a camera in the cockpit pointed at the
panel).  After I had been doing this for a few months, my boss
me to prepare some punch cards with the raw data, as they wanted
see if they could get one of their few computers (which belonged
the payroll department) to process the data (which I had already
manually so they would have something to cross check against the

computer output).

73 - Bob, N7XY

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