[ForSale-Swap] echo echo echo box box box

[James Duffer]

An echo box is an instrument consisting of a cavity (resonant circuit) that 
is tunable by a micrometer indicating type dial.  It was used daily at a 
long range radar sight.  By observing the time length of oscillation a 
relative indication of system performance could be obtained.  "Ringtime" as 
it was called depended on, among other things, the pulse power, receiver 
sensitivity, condition of TR/ATR switch, and the tuning of the box.  When 
peaked it would also indicate the frequency of the radar pulse.  The one I 
am familiar with was about the size of a large washtub and was on rollers as 
it was rolled between the two channels of the Long Range Radar.  The 
frequency of operation was L band approx 1300 MHz.  Obviously for higher 
frequencies, the box could or would be smaller.

73, Jim, wd4air


>From: doc <kd4e at verizon.net>
>Reply-To: kd4e at verizon.net
>To: forsale-swap <forsale-swap at mailman.qth.net>
>Subject: Re: [ForSale-Swap] echo echo echo box box box
>Date: Fri, 11 Mar 2005 14:04:38 -0500
>
> > Lloyd KK7IZ wrote:
>>Any one out there need, want, lust for a TS488A/UP echo box? I have one, 
>>no cover, has been professionally rack mounted for use in lab. $10 plus 
>>shipping. Thanx Lloyd  KK7IZ kk7iz at cox.net
>
>
>OK, only found a reference to 9GHz.
>
>What exactly does this thing do, please?
>
>Inquiring minds want to know!  ;-)
>
>
>--
>Thanks! & 73, doc kd4e
>
>           |_|___|_|
>           | | & | |
>              {|
>      /\      {|
>     /  \     {|
>    /    \    {|
>   /   @  \   {|
>   |   |~_|~~~~|
>   |   -| |    |
>============\ #    West Central Florida
>     KD4E     ==============================
>http://bibleseven.com/steelhouse1.html
>Ham PC = 100% Linux Novell-Suse 9.2
>Halli, Heathkit, Homebrew, MFJ, TenTec, Yaesu
>Radio Life: http://www.gospelcom.net/twr/
>Linux-Incompatible hardware is defective!
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>______________________________________________________________
>ForSale-Swap mailing list
>FAQ: http://mailman.qth.net/swap/swap.htm
>Home: http://mailman.qth.net/mailman/listinfo/forsale-swap
>Help: http://mailman.qth.net/subscribers.htm
>Post: mailto:ForSale-Swap at mailman.qth.net