[time-nuts] Re: Phase microsteppers
wa1raj at arrl.net
Thu Mar 10 17:31:37 EST 2005
The micro-steppers in question used for LORAN timing were indeed the
2055A units, if memory serves. I don't believe they supported 10 MHz,
but I didn't really pay much attention since the LORAN timers only used the
5 MHz output of the Cs standards for all requirements.
A 1 nS step size wouldn't be too difficult to accomplish in a home-brew
Finer resolution would be nice as you suggest, and is worth considering.
step insertion could easily be made programmable with a minimal processor,
and that's what I was thinking about implementing. I'd rather write code and
control the unit via serial port than cut a big square hole in the front
thumb-wheel switches ;-)
I'm going to have to consider going further with the design effort for
one of these,
as I believe it would be a useful addition to the tool kit here. If I
could find one
commercially (at surplus prices) I'd rather go that route, but judging
by what I've
seen out there and what others have said I don't think there are too
many of them
circulating on the market. Googling doesn't turn up much, either.
> Hi Carl:
> In an old Austron brochure is says their model 2055A Phase Microstepper
> works with either 1 or 5 MHz signals (no mention of 10 MHz).
> The adjustment range is from 0.00000 ns/second to +/- 9.99999 ns/sec.
> (i.e. 6 decades). "Exact time base frequency adjustments having a
> resolution of 1E-14 may be made." Note that 0.00001 ns/sec is 1E-14.
> It also has provision for changing the phase at a constant rate
> determined by the thumb wheels on the front panel.
> When I was trying to make a 1 PPS saw tooth corrector for the Motorola
> GPS receivers I found an IC that was a 1 ns phase shifter and had just
> enough range to correct the GPS receiver. I did get it to work but
> never could figure out how to get around the bug in the saw tooth data.
> This type of chip would be one way to get down to 1 or using another
> part number a fraction of a ns time step. But some other method must be
> used for finer steps.
> Brooke Clarke, N6GCE
More information about the time-nuts