World War II Navy Radio
Fixed Station
Home | The Radioman's Job | My Receivers | Mill | Point to Point | My Transmitters | Remote Control | Radiotelephone | Portables | Test Equipment | Frequencies | Training | Procedures | Museum Activities | Museum Ships | On the Air Activities | Navy Television | Men Who Lived It | Resources | Hints and Kinks | Nancy(Infrared) | Wanted | Contact Me

NOTE - This is a re-creation of Rob Flory's original site which crashed some time ago - unfortunately some photos are still missing but most of the text is here - if you can help with any replacement photos, please send e-mail to Rob or to Nick K4NYW

Click here for Nick's 1950's-60's Navy Radio Pages -  www.navy-radio.com

High Speed CW between Fixed Stations with Diversity Reception.

rdm.jpg
RDM Project, A Work in Progress

RDM
 
The RDM is a fixed-station diversity receiver using three RCA AR-88F receivers, also known as CRV-46246-A.  It lives in a 7-foot rack containing the 3 receivers, an antenna patch panel, a demodulator/tone keyer unit, a monitor unit, a speaker unit, and a power supply.  The three receivers were intended to be used with three dipole antennas apaced 1000ft. apart in a triangle.  In civilian life, the RDM was known as a DR-89. 
 
On AM or MCW, the demodulator/tone keyer unit combines the avc and detector outputs of the three receivers, so that whichever receiver is getting the strongest signal will mute the others and produce the output. 
 
On CW, the outputs of the detectors are rectified to produce DC voltages that are combined through diodes so that the strongest one produces the signal.  That signal is applied to a comparator, along with an adjustable threshold voltage.  If the signal exceeds the threshold, the comparator keys a tone oscillator, which can be fed to a remote location via a phone line.  Keying speeds of up to 600wpm are mentioned in the manual.  The output of the receiver could drive a tape inker, which produced "slips" that operators would transcribe visually.
 
In its current configuration, my unit consists of an AR-88F, an AR-88D, and an AR-88LF(Canadian-made RAF R.1556B).  Simple modifications have been made to the 2 latter receivers to feed the AVC line out to the demodulator unit.  Since I lack the monitor unit, and the D and LF units don't have an IF output for the monitor, right now I cannot monitor the individual receivers without taking the others off-line and temporarily disrupting the diversity action.

bc-1016.jpg
BC-1016 Paper Tape Recorder

This BC-1016 recorder was made by Waters Conley Company, Rochester, MN.  It records Morse up to 300-400WPM with ink on 3/8" paper tape.

tp100lowres.jpg
DeLisser TP-100 Tape Puller

This DeLisser TP100 tape puller was used to wind inked tape out of a redorder like the BC-1016 or pull inked tape past an operator so the message could be copied on a mill.  It has an orange Navy anchor stamp on it, and the reel is 3/8" wide, just like the tape used in the BC-1016 inker.

TRANSMITTERS
 
To transmit high speed CW, certain transmitters were equipped with vacuum-tube keying instead of the usual relay.  For example, the TBK-16, the shore version of that transmitter, used an 807 to screen-grid key the oscillator tube at up to 500 WPM.