[time-nuts] Accuracy/drift of Garmin GPS 16 HVS 1 PPS output under invalid fix conditions...

[Steve Olney]

Hi Tim,

On 13/03/2019 5:10 pm, Tim Lister wrote:
> Hi Steve, let me first off say that what your doing is very
> impressive;

Likewise - what you guys are doing time-wise is very impressive.

I think the level of precision you guys are aiming for is massive 
over-kill for my application.   Holding +/- 1 us over 15 minutes would 
be a doddle by many means as has been mentioned by you guys.  I just 
wanted to know whether the basic GPS mouse PPS would stay accurate 
enough to do the job for my application.

Radio astronomy is a hobby - i.e., a source of fun - although I do 
strive to maintain a level of scientific rigour to the best of my 
abilities.  One of the key drivers of the fun is doing things with 
simple systems.   I get extra pleasure in using a $20 DBTV dongle as my 
pulsar receiver to achieve the detection of a pulsar glitch (AFAIK the 
first time an amateur has ever done so on any pulsar).   You can pay up 
to $8,000 or so for the best SDRs. Hence, while more sensible/serious 
people might go the way of playing with more complex systems I am 
motivated to do it with as simple/basic a system as possible.   Granted, 
this approach does not always work - but when it does it greatly 
enhances the fun factor for me.

So - if I don't seem to be following the 'sensible' path you would 
probably be right ;-)

BTW - I have just had one of those wacky ideas pop into my head which 
has the potential to simplify things for my particular application.  I 
will evaluate it in the next week or so.

Cheers

Steve