On Monday, December 3, 2012 8:58:55 PM UTC-5, Arid ace wrote:
On Sun, 2 Dec 2012 23:07:55 -0800 (PST), wrote:



On Sunday, December 2, 2012 10:13:50 PM UTC-5, Arid ace wrote:

On Sat, 01 Dec 2012 07:02:26 -0500, Bob wrote:







Hi,







As apparently WWV doesn't transmit up that high in freq., what are some



good "freq. standard" signals to use for calibration in the vhf/uhf ranges ?







Thanks,



Bob







What could be used as frequency standard "plucked from VHF" is the TV line



frequency.



I'm not sure if like in Europe, all TV stations in the US would be equally



useful but if you enter this search string in Google



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"Calibration of high precision oscillators using the TV line frequency as a



frequency standard"



-----



you get several links that suggest it might be the case.







Jan



During the analog TV days maybe it was possible, but not now. I doubt if it could be done now at all...at least in the US. Best frequency standards are at low frequencies,such as 60KHz or even lower.



As far as I can remember, the time limit to end all analogue TV transmissions in

the US is somewhere in 2015 but if none are left already it's a pity.

However WWVB at 60 KHz now is modulated in phase just like happened with many

stations in Europe so you can forget to lock a 10MHz VCXO to the WWVB carrier,

to measure the drift of any XTO, even oven controlled ones. I looked up

available time & frequency stations and unless living close enough to Europe, no

luck: http://ac6v.com/standard.htm

We don't have any analog tv broadcasting since 2009 over here,in NYC. If WWV and its sisters like WWVB or WWVH cannot be used due to the phase modulation- I think the Canadian CHU still uses simple AM modulation or something very close to it.