Hi Joel
You are referring to this 1-chip VFO stabiliser ?. I do not recommend it unless you fancy a challenge. This circuit is an exercise, or a frollick perhaps you can say, a super-minimalist idea that I had. By that time I had built a lot of Huff Puff stabilisers and had lots of experience with their behavior. The 1-chip stabiliser does work but it is sensitive to VFO level, and the VFO should already be pretty stable to start with.?
A "safer" design with only slightly more complexity is this 2-chip design??which uses the "fast" method Huff Puff stabilisation. It is very stable and easy to get going.?
BOTH circuits work but the 2-chip design is a lot easier and will perform a lot better.?
This is similar to when people try ultra minimalist transceivers like the "Pixie", these have only a couple of transistors used as oscillator and PA and mixer all combined. They WORK but they can be challenging. Simple is great but sometimes something can be "too" simple in terms of parts count, only to make operation and results a lot more challenging. For this reason I wouldn't recommend a Pixie to a beginner constructor/operator. Similar arguments apply to Huff Puff stabilisers perhaps!
73 Hans G0UPL
---In BITX20@..., <caulktel@...> wrote :
Hans,
I asked this once before, but do you think the 1 chip stabilizer mentioned on your site would be adequate for the BitX40 VFO? I bought the chip and was going to give a try, but ended up putting a Si5351 VFO in instead. I would still like to know for further reference.?
Joel Caulkins
KB6QVI
On Dec 3, 2016, at 1:56 PM, hans.summers@... [BITX20] <BITX20@...> wrote:
?Hi
Please check for a library of practically everything that has ever been written about Huff Puff VFO stabilizers. As well as several practical projects of varying complexity and performance!
73 Hans G0UPL
Joel Caulkins/N6ALT