Interesting how these news items circulate the planet and
suddenly become topical:-
>Laura mentioned spread-spectrum in her post.
and Gary AB7MY mentioned
>Wonder how many of you heard Paul Harvey's program last week
>that credited the patent for spread-spectrum to the actress Hedi Lamar?
There was a third of a page on Hedwig Eva Maria Keisler (Heddy Lamarr) in
the friday edition of the U.K. broadsheet (what we call newspapers with more
than just pictures in!) of the Independent. Heddy and her Co-inventor George
Antheil
(a composer) had the idea of using a slotted piano roll to switch frequencies
in a predetermined pattern. Sadly, the Lammarr-Antheil patent expired in 1959
(it says in the article), just three years before frequency hopping was first
used
on ships during the Cuban blockade.
Back to our regular program, i.e. 38 Specials.
I tried Jim Kortge's mod:-
>Adjustable VXO setting capability:
>------------------------------------------
>Parts affected - L1. The reason for this change was two fold. I
>wanted to get as much range out of the VXO as was practical, and
>easily adjust the lower end to 10.1Mhz. This was accomplished by
>making L1 a 10uH choke connected in series with a 5-45pF trimmer
>capacitor.
....and I found that the oscillator became free running but that may have
been down to component tolerances and my 10uH may have not been
"on the nose". So I fitted the just the 6.8uH and wound a few extra turns on
it like we've been doing on the 4.7uH jobbie. The result was it tunes from
10.102 to 10.125. Now this covers where most of the action is over here
so I'm going to leave it at that and get on with the Paul Harden version of
the P.A. I rather fancy being able to switch the power (rather than
continuously variable) between 1 and 5 watts.
Countries worked so far on 300mW are the Czech republic, Denmark
and Spain. Where are all the U.S. NC38S's, or do I have to get up at
some ungodly hour to find you?
Looking forward to Dayton & FDIM
Tony - G4WIF
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