[GreenKeys] on-off radio teletype (not FSK)

[Richard Knoppow]

    The multiplex signals sounded to me like machinery running. 
Not to be confused with the Russian jamming stations that sounded 
to buzzsaws. They were also very strong. There were many 
multiplex signals on the West coast. I thought at the time they 
might have been coming from one of the commercial communications 
services like RCA in San Francisco but they were probably the 
Navy. It seems to me that there was a very large shared site near 
Dixon Ca, with Navy, commercial, VOA, Telco and probably other 
stuff. These days I hear mostly power line noise.

On 2/17/2018 3:11 PM, David I. Emery wrote:
> On Sat, Feb 17, 2018 at 07:58:09AM -0600, Jim Haynes wrote:
>> I'm talking about 1940s, early 1950s.
>> I'm not sure when FDM on the radio started, but think it was late 50s
>> or so.
>>
> 	I was born in 1948, so that era is mostly before my time... I
> do remember finding some papers in the mid to late 60s about early VFT

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL