[time-nuts] UK standard frequencies - where?
David J Taylor
david-taylor at blueyonder.co.uk
Wed Oct 12 06:43:25 EDT 2011
> I'm 70km north of London and have used the French 162kHz high stability
> signal as well as RWM (Moscow) on 4.996, 9.996 and 14.996MHz for
> frequency measurement and calibration before I got my Thunderbolt. RWM
> is particularly good because part of the schedule involves sending
> continuous carrier, which I used with SpectrumLab to calibrate
> transceivers - you simply use SSB, offset the transceiver by 1kHz to get
> an audio tone and measure the error using the waterfall on SPLab.
Yes, I can get the RWM on 14.996 MHz - so that's an excellent HF start.
> The technique is prone to sound card errors but these can be quantified
> and there are various tricks which can be used to minimise error,
> probably better discussed by e-mail.
OK, but I'm probably OK for the moment.
> I'd be (pleasantly) surprised if local FM transmissions operated to
> time-nuts levels of stability, but I can assure you that air traffic
> transmitters are probably not the way to go. Air traffic transmissions
> have 25kHz spacings but some allocations have multiple transmitters at
> different sites all using the same channel, but frequency offset from
> each other to give wider coverage - and of course, with the exception of
> VOLMET and ATIS transmissions, the signal is very intermittent.
Yes, it's been a bit hit-and-miss, and I suspect that all of the local
transmitters were aligned by the same team, perhaps even the same
instruments. Quite close agreement, but are they correct?
> Your best bet would probably be to get hold of a Thunderbolt as I did,
> you can also feed the 10MHz output to a set of dividers if you have
> test gear which can use external an external frequency reference - very
> David, Milton Keynes, UK (G4IRQ)
Something like a T/B but using a pre-amped puck antenna would be ideal for
Many thanks for your help.
SatSignal software - quality software written to your requirements
Email: david-taylor at blueyonder.co.uk
More information about the time-nuts