[time-nuts] HP 3586A/B/C entirely referenced to 10MHz: A solution II

[Perry Sandeen]

Fellow Listers,

Please read and think a bit about my comments before rushing to the reply button.  The comments are meant to be technical.

When Burt VE2ZAZ posted his HP 3586A/B/C entirely referenced to 10MHz: A solution, I was drooling with envy to add it to my units.  However, after reading what it took to make and program it I was completely deflated.

While there are those on the list with extensive educational and technical resources, Burt’s project may be just fine.  And for those who can make it, go for it.  I made a pros and cons list.

Advantages	                 Dis-advantages
Small- Will fit inside case	 SMD Components
Low power requirements	         Needs Programming 
Inexpensive	                 Program varies for various models
Awesome build quality	         Almost comes up with the correct numbers

Sometimes the only way to solve a problem is with SMD’s, programmed devices etc.  But I suspect that for most of us “solutions” of this type are really impractical.  Some posts seem to suggest that everyone can program devices, write code, and can work with SMD’s as easily as getting a hamburger at Micky D’s.  It just ain’t so.  On my level I have to use the KISS principle.


Several alternative methods:

The cheap method.  Turn the crystals 90 degrees so they are perpendicular to the PC board.  Make a simple TL431 temperature regulated circuit (I found it on the web by a google search) with a bit of copper and insulation.  A small supplemental adjustable tuning capacitor and/or varicap circuit may be needed.  It will probably get one as close as the original programmed mod IMHO.

The high priced exact solution.  Use a HP 3336 locked to the same external standard one is using for the HP 3586B.  Remove the original crystal circuit and inject the exact number one needs and get the exact results without any dithering.

I’m blessed to have almost all the test equipment, or its equivalents, mentioned on this list sans a spectrum analyzer and from post’s that I have read I’m way ahead of many of the members.

I’ve been very impressed, and have learned a great deal, with the posts on the T’bolts, answers to my posted qurstions, WWVB, and HP oscillator fine tuning tips to name a few.

On subjects over, or in many cases way over, my head I just read and delete but others find them both fascinating and useful and that’s just fine.

Regards,

Perrier