[NJARC] Fw: Radio Question

[Al Klase]

Hi Evan,

The topic that comes to mind here is Telemetry in general and 
meteorological radiosondes and dropsondes in particular. The earliest of 
these dates to the 1930's. See: 
http://www.aos.wisc.edu/~hopkins/wx-inst/wxi-raob.htm

These typically multiplex analog signals for pressure, temperature, and 
relative humidity onto a single radio carrier. They only weigh a couple 
of pounds, and are throw-aways.

My favorite is the AN/AMT-3. This is actually a dropsonde, i.e. 
parachuted from an aircraft. The three mechanical sensors move three 
tone arms that sequentially play two-letter groups in Morse from the 
raised quadrant of a phonograph record. The output modulates a 
single-tube transmitter on 3135KC. The beauty of this is that no special 
equipment beyond a general coverage short-wave receiver is required in 
the plane. I think I have one among my stuff.

They did work on these at *the** Temperature Standards Laboratory, Evans 
Signal Laboratory. There a minor reference on the InfoAge site.

Regards,
Al
*
Ray Chase wrote:
> Visit our web site - See http://www.njarc.org
> _______________________________________________
>
> ----- Original Message ----- 
> From: Ray Chase
> To: NJARC
> Sent: Monday, December 17, 2007 9:06 AM
> Subject: Radio Question
>
>
> Evan Koblentz of the MARCH computer group at InfoAge posed the following
> interesting question to several of us:
> "I was wondering today .... are there any radios from before 1993 ..
> specifically radios that are portable/meant to be carried around ... that
> sent/received any kind of data other than voice?  Please enlighten me with
> specifics."  Obviously there are CW (morse code) devices and maybe some
> military stuff but I cannot think of any others.  Any comments?  Obviously a
> referance to the introduction of data transfer on cell phones etc.  Evan is
> at evan at snarc.net.
> Ray
> _______________________________________________
> NJARC mailing list
> NJARC at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/njarc
>
>
>   

-- 
Al Klase – N3FRQ
Flemington, NJ
http://www.skywaves.ar88.net/