Gamal,
At 08:25 1.3.2000 +0100, you wrote:
GS> just see your regular Decca FS measurements.
There was no need to measure other than *Green* freq's.
It is a miracle that all 7 Green freqs have been
possible to measure day after day. A lot of QRM.
I'll produce a summary of measurements after 31st March
when the Decca story is completely finished - for ever.
GS> Recognize that you "only" have measured the
GS> green channels. As far as I understand the working
GS> of Decca as a system, it consists of purple, master,
GS> red, orange and green channels. The orange channel
GS> being not relevant for navigation purpose, instead for
GS> identification (?) and system status information (?).
Q> Do you have some more detailled info?
Decca format is so complicated that to explain how
it works would cover several pages. Also, the format
went thru a couple of large modifications in the past.
Q> My main concern is, how can one identify a specific
GS> station by other means as measuring frequency and
GS> look-up table.
The five frequencies are *channelized*, so is receiver.
Q> Are the purple, master, red and green channels
GS> purley unmodulated CW signals?
Yes, plain carriers without modulation.
GS> In the past I did monitor Decca on rare occasions
GS> once to put up a list of receiveable signals (now
GS> years ago). As my receiver is in repair I cannot
GS confirm this myself at the moment.
In January, after Scandinavian Deccas were shut down,
Matti, OH2BDQ telephoned me and asked whether I understand
what are all those remaining (Decca) signals. I said that
tried to monitor and measure them, but don't understand.
Matti is in charge of local Decca station at Mantsala and
has been working with them most of his adult life.
Mainly, the short *extra peep's* make it complicated
as they are transmitted in apparently random manner.
73 de Vaino
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