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Re: [TowerTalk] the elusive 1db

To: TowerTalk List <>
Subject: Re: [TowerTalk] the elusive 1db
From: Bob Nielsen <>
Date: Tue, 15 May 2007 18:24:53 -0700
List-post: <>
On May 15, 2007, at 3:02 PM, Pat Barthelow wrote:

> That elusive DB just reared it head at Jamesburg.  We discovered  
> that our
> dish has neither parabolas, or hyperbolas as part of normal Cassegrain
> surfaces.  Mike Brenner, our laser metrologist just determined that  
> the
> dish, built by Philco Ford in Late 60s, probably designed in early  
> 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 get  
> one more
> DB to listen to Geosynchronous Satellites.
> But a more interesting question, in light of the fact that this was  
> before  the HP 35 was around , (;>)  in fact in the REAL olden days,
> 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 and  
> 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 but  
noisy Friden mechanical calculator on my desk to use in processing  
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 instrument  
panel).  After I had been doing this for a few months, my boss asked  
me to prepare some punch cards with the raw data, as they wanted to  
see if they could get one of their few computers (which belonged to  
the payroll department) to process the data (which I had already done  
manually so they would have something to cross check against the  
computer output).

73 - Bob, N7XY

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