I'm reposting this because my server is messed up and some of you may
not have seen the post.


I don't no if any of you have ever used spectrum displays as a tool for
DX work but heres a freq converter I made to hook up my CEI/ WJ
spectrum monitor to my R-5000. Pete KE9OA was helpful along with a few
others. Thanks Pete. It's a fairly simple design useing the NE602 mixer
chip. The hard part is getting the the Osc. to oscillate because its a
very faint signal and a spectrum monitor would be ideal but most of us
don't have one so a radio tuned to the right freq will work with a
little patience. I had to swap a few differant values of caps in the
Osc. circuit for it to work on the freq. I needed. The only math
involved is this: If the spectrum display wants to see a 21.4mhz
signal at its input and your radio has a 10.7mhz IF output you add 21.4
plus 10.7 = 32.1mhz. Get the coil and cap on pin 6 to oscillate at
32.1mhz and thats all that it needs to work. The ne602 takes the 10.7
and mixes it with the 32.1 and outputs 21.4mhz to the display. If your
radio has a 45.0mhz IF, 21.4 plus 45.0 = 66.4mhz. Get the coil and cap
at pin 6 to oscillate at 66.4 and you are all set. etc...


I also
have a dual 1261-S Microdyne Corp unit Im working on that will be used
with
my other receivers.
http://webpages.charter.net/brianhill/IMG_0247.jpg

Heres the circuit diagram.
http://webpages.charter.net/brianhill/conv.jpg

Here's what I fabed up.
http://webpages.charter.net/brianhill/conv2.jpg
http://webpages.charter.net/brianhill/conv3.jpg
http://webpages.charter.net/brianhill/conv4.jpg

73 and good DXing.
Brian
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A lot of radios and 100' of rusty wire!
Zumbrota, Southern MN
Brian's Radio Universe
http://webpages.charter.net/brianhill/

EMAIL-
(Hide the $100 to reply!)

Hey Brian,
It looks good. It looks like you are running the chip on 5
volts. An NE602 likes to have at least 6 volts. 8 volts is ok
too.............I use a 7808 to run the chip. You might find that the chip
operates better at this higher power supply voltage.
Nice job on the design!

Pete

"Brian Hill" wrote in message
oups.com...
I'm reposting this because my server is messed up and some of you may
not have seen the post.


I don't no if any of you have ever used spectrum displays as a tool for
DX work but heres a freq converter I made to hook up my CEI/ WJ
spectrum monitor to my R-5000. Pete KE9OA was helpful along with a few
others. Thanks Pete. It's a fairly simple design useing the NE602 mixer
chip. The hard part is getting the the Osc. to oscillate because its a
very faint signal and a spectrum monitor would be ideal but most of us
don't have one so a radio tuned to the right freq will work with a
little patience. I had to swap a few differant values of caps in the
Osc. circuit for it to work on the freq. I needed. The only math
involved is this: If the spectrum display wants to see a 21.4mhz
signal at its input and your radio has a 10.7mhz IF output you add 21.4
plus 10.7 = 32.1mhz. Get the coil and cap on pin 6 to oscillate at
32.1mhz and thats all that it needs to work. The ne602 takes the 10.7
and mixes it with the 32.1 and outputs 21.4mhz to the display. If your
radio has a 45.0mhz IF, 21.4 plus 45.0 = 66.4mhz. Get the coil and cap
at pin 6 to oscillate at 66.4 and you are all set. etc...


I also
have a dual 1261-S Microdyne Corp unit Im working on that will be used
with
my other receivers.
http://webpages.charter.net/brianhill/IMG_0247.jpg

Heres the circuit diagram.
http://webpages.charter.net/brianhill/conv.jpg

Here's what I fabed up.
http://webpages.charter.net/brianhill/conv2.jpg
http://webpages.charter.net/brianhill/conv3.jpg
http://webpages.charter.net/brianhill/conv4.jpg

73 and good DXing.
Brian
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A lot of radios and 100' of rusty wire!
Zumbrota, Southern MN
Brian's Radio Universe
http://webpages.charter.net/brianhill/

EMAIL-
(Hide the $100 to reply!)