[time-nuts] Thunderbolt SV and AMU Signal levels

David Ackrill dave.g0dja at tiscali.co.uk
Wed Jul 23 16:28:49 UTC 2008


GandalfG8 at aol.com wrote:



> If your counter will accept an external reference I'd suggest using the  
> Thunderbolt for that and just trusting the results.
> However, if the figures you've shown represent the resolution limit of your  
> counter then you may want to consider a counter with better resolution, still  
> using the Thunderbolt as a reference of course, but just watch your balance  
> as the downward slide continues:-)

Thanks Nigel,

Yes, I suspected the counter, rather than the Thunderbolt.  After all, 
as I said before, the counter is over 20 years old and probably wasn't a 
cutting edge design even then.  It was bought from Maplins in Erdington, 
Birmingham, just a year after I got my old G6 callsign.

The thing with precision and accuracy is that it's all relative to 
whatever standard you have to measure the readings you get against. This 
frequency counter of mine has never been checked against any form of 
standard since I bought it anyway.

In my case, as long as the 10MHz output keeps the frequency of the 10GHz 
transceiver (when I save enough to get one) in one place long enough for 
another station to find it, whatever the nth decimal place might be, so 
that we can make a contact, that will be fine by me.

I've had the Thunderbolt and the counter running for over 24 hours now, 
and the 5th decimal figure, for a 1 second gate time, seems to have 
settled down a bit.  Now, that could be the counter , or the 
thunderbolt, or both.  Who can tell? :-)

The next arguement usually goes along the lines that, according to what 
I hear from some physicists, the very act of measuring something changes 
it...

Dave (G0DJA)




More information about the Time-nuts_lists.febo.com mailing list