[time-nuts] Thunderbolt accuracy...??
Dave Ackrill
dave.g0dja at tiscali.co.uk
Sat Dec 20 20:42:11 UTC 2008
Hal Murray wrote:
>> versus junk GPSDO
>>
>
> It's not junk.
>
> What are you interested in? Short term stability or long term accuracy?
>
I'm glad to hear that the Thunderbolt is not classed as 'junk'... :-)
Personally, what I want to do is two things. 1. Keep my PC clock within
a reasonable time frame when compared with other PC clocks for Amateur
Radio data mode transmissions. In this case, the actual time seems less
important than the effective time between the other station and myself,
so that we don't try to transmit at the same time, or receive at the
same time. What that time is, is not that critical, as far as I can
see. As long as we both agree when to transmit and when to receive.
2. I want to keep various transverters reasonably on frequency when
compared to other people who may, or may not, be 'on frequency' so that
we have a better chance of finding one another on UHF and SHF bands when
we set a frequency to transmit or receive on.
The Thunderbolt 10MHz GPSDO seems ideal for this second application.
The more accurate and stable the better, of course, but in comparison
with some older transceiver or transverter designs the Thunderbolt
option to lock in a frequency should be far in advance of many of the
older hit and miss operations when trying to agree upon what frequency
is in use on the SHF bands.
From what I can make out, the next technique to address is to use SDR
technology to identify when someone is even a few Hz away from where you
think they might, or should, be.
The pursuit of perfection is a laudable goal, but it can obscure the
original objectives that you wanted to reach, in my opinion, if you are
not careful.
Dave (G0DJA)
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