[GreenKeys] FRF FSK conv. (was - Two eBay Novelties)

[Duncan Brown]

I don't think there would have been much leakage through the steel hull 
of a ship.  The actual radio receivers were probably radiating a lot 
more  of their LO energy back out their antennas.

Duncan

On 09-Feb-14 16:41, COURYHOUSE at aol.com wrote:
> they mean radio signal leagage that would allow   bad guys  to find 
> and  torpedo  you
> In a message dated 2/9/2014 2:22:26 P.M. Mountain Standard Time, 
> duncanancy at earthlink.net writes:
>
>     The FRF looks like an early version of the CV-31B/FRA-7 used in
>     the AN/GRC-26 (c1950) and discussed here recently.
>
>     I wonder about the "Warning - Radiation exceeds safe limit -Do not
>     use aboard ship" label.  Were they worried about RFI?  to or from
>     the FRF??
>
>     The specification for the FRF is available at
>     http://jptronics.org/radios/Military/JANAP161/an.fcfg/an.fga-type.frf.pdf
>     .  It mentions tone _oscillators_ at 170 cps apart. It almost
>     implies a multiplexed system of 170cps shift signals on one
>     carrier  or sideband (which was done in WWII), but I think the FRF
>     (and certainly the CV-31) is a single channel output (one TTY
>     signal). It was probably designed for 850 cps shift, though might
>     work down to 425 cps shift.  Military converters often had a keyed
>     tone (OOK) output if the demodulated TTY signal needed to be sent
>     any distance from the RX site to where the actual TTYs were located.
>
>     The AWA Museum has a CV-31B/FRA-7, so we will not be bidding on
>     this, but it does belong in a museum!
>
>     have fun,
>
>     Duncan
>     K2OEQ
>
>     On 08-Feb-14 21:04, David Burns wrote:
>>     WWII Navy Western Electric Model FRF Receiver Frequency Shift Ham
>>     For Teletype
>>     <http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221370706399&fromMakeTrack=true>
>>     This is an odd duck...Navy dual-channel I.F. demodulator with 170
>>     shift, but preset at eight odd military frequencies, designed to
>>     interface with 1940 RBB/RBC battleship receivers.  There is stuff
>>     on the web if you search with the "CW-####" FRF numbers.  "Not
>>     for shipboard use", but the shipboard equivalent equipment seems
>>     to have been canceled.  Which would explain why this unit was
>>     never used.  I sent mail to the seller suggesting they list the
>>     associated teletype machine /they still have crated up!/  (That
>>     could be very interesting!)
>>
>>     Telegraph / Teletype Machine WUTEL Western Union Quotation
>>     Service
>>     <http://www.ebay.com/itm/231153851639?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT>
>>     This ticker is missing the motor (and other parts?)
>>
>>     -Dave in Boston
>>
>>
>>
>>
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