[time-nuts] Trak 8810 Station Clock

[paul swed]

Chris
What Bob was mentioning is true of the older units circa 1990s. I have
homebrewed down converters for two older units. Essentially everything gets
multiplexed onto the one jack so you can't really tell by looking if it
needs a downconverter or just an antenna. A bit of a hint. If there is
something like 12-15VDC on the jack then it needed a down converter. But
its just a hint not a rule.
Its funny how you find great receivers for $0 only to find out a key
component is missing.
Thats how I ended up with my Austron.
Good luck
Paul
WB8TSL

On Sat, Jul 20, 2019 at 9:00 PM Chris Quayle <syseng at gfsys.co.uk> wrote:

> Hi
>
> > It’s a pretty good guess that a device from that era ran a
> “downconverter” head end.
> > They had a full RF front end out at the antenna and fed some sort of IF
> frequency
> > back to the unit. Various outfits had approaches to how to do it. The
> net result is that
> > the head end is pretty specific to this or that box (or at least series
> of boxes).
> >
> > Since it’s an entirely different approach to getting things done,
> directly replacing the
> > head end with a modern module is going to be tough. The normal
> alternative is to
> > build up a downconverter. Some do it from scratch, others find a similar
> unit
> > somewhere and modify it to do the job. The big trick is to find out
> exactly what the
> > main box is looking for ….
> >
> > Bob
>
>
> I had wondered about that, but if you look at the antenna input, it
> looks like pretty high frequency, with a track inductor. Would
> assume that a downconverter from gps frequency would
> translate to baseband, but may be wrong.
>
> Took a few pics of the board, in case it looks familiar to
> anyone, but it must have been used on other, perhaps marine or
> avionics kit of the time. Problem is finding such an item, say
> on Ebay, without taking the lid off to verify contents. Have a
> feeling this quest may take some time :-).
>
> Here are the pics anyway:
>
> https://www.flickr.com/photos/182770787@N05/
>
> Regards,
>
> Chris
>
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