[Elecraft] K1 K2 - Interesting noise

[Phil Kane]

On 7/2/2011 2:48 PM, Ron D'Eau Claire wrote:

> There was general relief all over the area when the huge antenna
> disappeared from the mountain.

  The FPS-24 long-range Air Defense search radar antenna was
  huge, all right. and it operated in the 214-236 MHz range wiping
  out TV Channel 13 (Sacramento) reception and 220 MHz band
  operation in the SF Bay area.  One didn't realize how big it
  was until one was at the site.  Then there was the FPS-90
  (affectionately called the "Tipsy One D" after an earlier
  model), an S-Band height finder radar, which nodded in a
  vertical plane while being slaved to a bearing in the
  horizontal plane corresponding to a target in the search radar.
  The hidden "gem" on that hill was the UHF (300 MHz band)
  multi-KW ground-to-air data link, with a final tube the size of
  a wastebasket.  General Electric made a fortune on that system.

  This was all tied into the Air Defense Command SAGE system (of
  not-so-blessed memory) and I was given the "nickel tour" there
  in the late 1970s shortly before it was decommissioned.

  Lest I be accused of "disclosing national secrets", this is all
  written up in Wikipedia articles, as has most of the hush-hush
  projects that I worked on during the Cold War.  Start with
  "Almaden Air Force Station".

> Little did I, or anyone, realize at that time that we were about
> to be invaded by millions of noise switching "wall warts" and
> other digital noise generators. Quieting Umunhum's noise was
> child's play compared to dealing with them.

  The functions of that system were moved to the PavePaws system,
  and those of us using the 70 cm band in the San Francisco -
  Sacramento area became well aware of that system when we were
  ordered by the FCC at the behest of the USAF to lower 440 MHz
  repeater powers, in some cases to single-digit watts, to avoid
  interfering with PavePaws.  Many repeaters just went off the
  air.

  Back to Elecraft....yes, the wall-warts come in two flavors -
  those that are "clean" and those which I send to the recycling
  bin.

--  73 de K2ASP - Phil Kane
    Elecraft K2/100   s/n 5402