Huff n Puff

I've been considering having a play with Huff n Puff VFO stablizers for quite some time; there are plenty of resources out there to explain this concept:

http://groups.yahoo.com/group/HuffPuffVFO/

http://www.hanssummers.com/huffpuff/minimalist/2chip.html

I've been reading with interest the experiments done by Hans Summers:

http://www.hanssummers.com/

And have had a go today at building his 2-chip VFO + Huff Puff; which is an exceptionally clever design.

Here's a picture of the schematic as drawn by Hans:



I've built it using veroboard, and paid no real attention to layout:



Now the output from this VFO is, as you would expect, rock solid:



What I'm planning to do is build a QRSS beacon and receiver for the shack:

http://www.sdrham.com/

Next is to build a Huff Puff stablised VFO on 10.140MHz for the QRSS receiver, and then think about how to build the beacon....

More will follow.