[Boatanchors] F.T. RTTY Keyers: KY-58/GRY, KY-75/SRT

[n1udi at att.net]

Gent's 

I have for trade to towards some other Mil-type Receiver,Transmitter, Amp equpiment.
The units are a MC-765/URT Modulator-Power Supply and a AM-655/URT Amplifier-Oscillator.  Here's what they are and what they do as per the Navships 91543
Purpose and basic principles. 
The AN types KY-58/GRT and the KY-75/SRT keyers are directly calibrated frequency-shift exciters in which signaling is accomplished by shifting a constant amplitude carrier between two fixed freguencies repersenting the marking and spacing conditions of the telegpraph code or varying intensity of the facsimile(photo) signal. 

The keyers can be connected to different types of Navy transmitters and are arranged so that closure of the contacts of a telegraph key, to teletypewriters, produces a marking signal which causes the transmitter to emit a frequency of the transmitter. The opening of the contacts of a telegraph key or a teletypewriter produces a spacing signal which causes the transmitter toemit a frequency below the normal assigned frequency of the transmitter. The varying facsimile signal produces a marking and spacing condition similar to that of frequency-shift keying.

The primary purpose ofthe frequency-shiftkeyer is to replace the conventional exciter of a C.W. transmitter, with a source of R.F. exciation that can be shifed in frequency a small amount upward and downward to produce R.F. telegraph or facsimile signals corresponding to the d.c. polar, neutral or facsimile input signals connected to the keyers. 

The AN types  KY-58/GRT or KY-75/SRT  keyers transmit a type F1 frequency shift signal or F4 facsimile signal in the frequency range of 1 to 6.7 MC's. The out put of the keyer can be applied toany existing C.W. transmitter, capable of operating from a 2 to 20-volt excitation source, for passage through clas 'C' amplifier or multiplier stages. The keyer is used principlly for comparatively long range commuications in the HF range.

Well that's it in nut shell the only difference in the two units is the KY-58/GRT is in a tal rack wkth casters and shock mounts, hight 42 in. The KY-75/SRT is in a short rack desk mount with shock mounts hight 24 1/2 in. I don't have either of the two racks, just the units by them self.

I'm not into RTTY  so I have no use for them, but could use another  mil radio or two. The MD-165 /URT is to heavy to ship but it's your call! est weight 75lbs,  so a local p/u is in order or I will meet some with in a 100 mile radius of Southern Connecticut, ref point Yale Univ. I don't any jpg's of the two units but will work on it. 

 So what you got for trade?

Rock