On 10/6/2014 12:38 PM, Peter Able wrote:
On 06/10/2014 16:43, rickman wrote:

building this. But there is only one problem with the idea. To use the
Si570 as the VFO for a receiver it would need to output a sine wave.
However the Si570 outputs square waves for digital circuitry. I don't
think the mixer would appreciate all the harmonics produced in a square
wave would it?

Then use a DDS.

There are lots of things you could do. I think Gareth got the idea
because the Si570 looked like it would be easy to use. But it just
doesn't fit the bill.

What frequency range would be of interest for tuning these older
receivers?

Once I read up on the Huff and Puff modification, I like the idea. It
doesn't change the receiver really, it just keeps it on the correct
frequency by using the VFO as a VCVFO. Is it common to have a voltage
control on the VFO in these receivers? Or is that a mod that would have
to be made?

--

Rick