[CW] DDD SOS DDD from GLD

[Richard Knoppow]

    A2 or A3 was used for distress traffic on 500Khz because 
there were numerous crystal emergency receivers in use. All the 
autoalarms responded to tone telegraphy, anything from about 
400Hz to 1 Khz, they did not respond to CW.
    The RCA station in Los Angeles, KSE, used A2 when making 
calls on 500Khz. Evidently, the oscillator was keyed when the 
transmitter went on the air because the tone faded in after a 
couple of seconds, sounded like the filaments were warming up.
    A2 is where a modulated carrier is keyed, A3 where the tone 
is keyed on a steady carrier.  All this is a carry over from the 
days of spark (Class B) which is sort of modulated, sounds like a 
buzzer. Description meant for others, I know you know this stuff 
Dave.

On 12/21/2018 5:57 PM, D.J.J. Ring, Jr. wrote:
> I thought some would like to hear a recording of Land's End 
> Radio/GLD involved in a SOS sending DDD SOS DDD (SOS Relay) messages.
> 
> Finbar EI0CF (retired from Malin Head Radio/EJM) posted a DDD SOS 
> DDD from Lands End Radio/GLD.
> 
> Beautifully done.
> 
> I thought people would like a listen:
> https://archive.org/details/MalinHeadRadioEjm-The500KhzRecordingsOfFinbarOconnorEi0cf/RegSosGLD080394Mod1.mp3
> 
> More here: 
> https://archive.org/details/MalinHeadRadioEjm-The500KhzRecordingsOfFinbarOconnorEi0cf
> 
> 
> Lands End Radio/GLD appears to switch from A1A CW emission to 
> modulated to A2A Modulated Continuous Wave (MCW)  right after SAG 
> Gothenburg Radio, Sweden makes an TTT (Navigation Warning) for 
> DECCA malfunction, etc.  Notice the change in tone and how much 
> easier it is to copy. There are three "tones" on a MCW signal 
> with BFO reception, lower side band, carrier and upper side band, 
> at least one tone usually gets through the 500 kHz interference.
> 
> 73
> DR
> 
> 
> 
> 
> 73
> 
> DR


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