CW Ident timing

[G0DJA]

Hi all,

Not surprisingly, I can hear GB3MBA from its new location near Mansfield, as it's only about 14kM away from me.
However, the ident seems to come up at about 10 minutes and 36 seconds. So, it's not transmitting on 10, 20, 30, 40 and on the minute exactly, it moves on by about 36 seconds each time.

I've got some nice AS screen shots from SpectrumLabs as well.

Dave (G0DJA)

[G0DJA]

I've done a few more timings using a stopwatch, and the ident seems to occur every 10 minutes 32 seconds after the start of the previous ident.

[briang4nns]

Hello Dave. The CW is generated by PIC using it's internal oscillator it was not intended as a precision timing system but merely to meet the OFCOM requirement that it identify. Frankly this requirement is a bit of a nuisance. Phase II of this project is to develop and deploy multiple receivers to form a bi-static radar network to calculate location, velocity and trajectory by analysis of Doppler shift of head echoes at a mutual instant. For that purpose, precision timing ( and frequency control) is required at each receiver to eliminate latency through the receiver and internet. We are looking for volunteers to assist with Phase II. All the best
Brian

[G0DJA]

Hello Dave. The CW is generated by PIC using it's internal oscillator it was not intended as a precision timing system but merely to meet the OFCOM requirement that it identify.

Thanks for the reply, Brian,

Unfortunately, when people read that it's sending an ident every 10 minutes they might, like me, assume on the 10, 20, 30, 40, 50 and 60 second mark. The continuous tone is, let's say, unusual in the Amateur Beacon system. Until the word gets out that the ident is only approximately 10 minutes, it might cause some confusion about identifying it at long range.

It's such a strong signal here I doubt if I'll be able to use it for MS.