Frequency sintetizer for heteordyning

[Alessandro Esposito]

Hi,
I have two very wonderful IFR signal generators but also quite
expensive. They are perfect but I want to test some cheap version of my
instrument that is an advanced microscope.
I know people replaced, in applications as mine, a signal generator with a
NE555... wow... I mean... I worked with NE555 14 years ago when I was 14
y.o.
At the moment I'm working at MHz region with two equal but tuneable
frequencies with a certain phase delay between them. Supposing to move in
the KHz region I think I could use NE555.
So the questions are:
1) does exist an easy way to use to coupled NE555 with the same frequency
but with a adjustable phase delay between them?
2) is it possible to use NE555 to have two slightly different frequencies,
in the way I can control the difference?
3) is there some chip easy to use as the NE555 but that work in the MHz
region?

Ok... I thank you anyway... hoping for some suggestion or references. Is
there some website with schematics?
Bye
Alessandro

 

[Bill Sloman]

Hi,
I have two very wonderful IFR signal generators but also quite
expensive. They are perfect but I want to test some cheap version of my
instrument that is an advanced microscope.
I know people replaced, in applications as mine, a signal generator with a
NE555... wow... I mean... I worked with NE555 14 years ago when I was 14
y.o.
At the moment I'm working at MHz region with two equal but tuneable
frequencies with a certain phase delay between them. Supposing to move in
the KHz region I think I could use NE555.
So the questions are:
1) does exist an easy way to use to coupled NE555 with the same frequency
but with a adjustable phase delay between them?
2) is it possible to use NE555 to have two slightly different frequencies,
in the way I can control the difference?
3) is there some chip easy to use as the NE555 but that work in the MHz
region?

Ok... I thank you anyway... hoping for some suggestion or references. Is
there some website with schematics?

Sounds like a job for one of the Analog Devices direct digital
synthesis (DDS) chips. At least one of them can produce two outputs at
the same - finely programmable frequency - and with a programmable
phase difference.

http://www.analog.com/UploadedFiles/Data_Sheets/87202050AD9854_b.pdf

The NE555 would be a waste of time in this context.

Hope this helps. You should post more details of the application if
you want a useful recommendation - e-mail me if you don't want to go
that public (I've got some history with advanced microscopes ...).