[time-nuts] Call for input and beta testers -- Simple Distribution Amp/1pps divider

John Ackermann N8UR jra at febo.com
Fri Jun 3 16:40:30 EDT 2005

Hi All --

I'm working on a new project for TAPR that some of you may be interested 
in, and I'm soliciting your input, as well as three or four of you to be 
beta testers.

By way of background, TAPR (http://www.tapr.org) is an international ham 
radio organization that supports advanced R&D work in ham radio.  For 
the last several years, I've been its President (i.e., chief cook and 
bottle washer).  Although TAPR started by developing hardware for packet 
radio, we've been involved in time and frequency stuff as well.  We 
supported the development of, and marketed, the "TAC" (GPS interface 
board) that's used all over the world in GPS timing systems, and we're 
about to introduce the Reflock II, a PLL system designed to lock an 
oscillator of virtually any frequency to a frequency reference or GPS input.

I'm just about finished designing my first TAPR project, and it's one I 
think this crowd might find useful.

It's a combination distribution amplifier and 1pps divider built on a 
single circuit board.  The key features are:

*  Broadband amplifier (from near-DC up to about 30MHz, with usable 
response out well beyond that.  There will be an optional bandpass 
filter to reduce spurs from, e.g., a square wave input.

*  50 ohm or high-Z input, with 4 buffered and isolated 50 ohm outputs.

*  PIC-based divider that can generate 1pps output from 100kHz, 1MHz, 
5MHz, or 10MHz inputs.  It has a synch input to for setting against an 
external pulse, and provides two low-Z outputs.  (The code is based 
heavily on the design that TVB published, and is used with his permission.)

I have some specific questions about the feature set that I'd like to 
ask potential users, and I would also like to find three or four people 
willing to build beta versions of the kit (it's through-hole technology 
and assembly should be fairly straight-forward, but will require basic 
electronic assembly skills).  Beta testers will be asked to pay the cost 
of parts, and can keep the beta unit when testing is finished.

Our hope is to have the beta kits available within six to eight weeks. 
We'd like anyone buying a beta kit to commit to building it within a 
month after receipt.

If you're interested in providing design input, or being a beta tester, 
please contact me off-line.  I'll be setting up a separate mailing list 
to handle the discussion.



More information about the time-nuts mailing list