Also...
The open-loop stability of the oscillator, especially the 7-20 range, will
probably be too poor for the huff-puff to keep up and microphonics will
undoubtedly be an issue. Overall, a very daunting project in my estimation.
From: Ashhar Farhan
Sent: Friday, March 31, 2017 11:24 AM
To: minima@xxxxxxxxxxxxx
Subject: [minima] Re: Finally getting around to building my Minima...
A simpler scheme than the Si570 is to use a lower frequency IF like 11 MHz.
Make a solid JFET VFO in a shielded box that has two sections, one that goes
from 3 MHz to 7 MHz, the other that goes from 7 MHz to 20 MHz. Then, just add a
very simple Huff and Puff.
This scheme may look basic, it is not. The phase noise of such a system will
beat the best of the radios on the market.
It is not exactly easy either. First, you need a very nice tuning capacitor
with slow motion drive. Next, you will need good mechanical skills to build the
VFO.
- f
On Fri, Mar 31, 2017 at 7:59 PM, Mark Pilant <mark@xxxxxxxxx> wrote:
My plan all along has been to try different mixers. First the KISS mixer,
then a Mini-Circuits ADE-1, and finally the FST3253. I'm sure it will be
an interesting exercise.
73
- Mark N1VQW
