David wrote:
Andy,

Thanks. I am using single-ended output from the SA602 as well as for the
SA605 input. I decouple the unused output/input with 100n Cap in each case.

How do you know the match is working correctly ? My concern is that when
I build the circuit and sweep it with a sig gen and tune it for peak,
how do I know the match to is correct in the first place.

Regards

David


Andy replies:
Personally, I would use PSPICE to simulate the circuit to see if it
peaked
at the right point. Then I would measure the voltage at the top of the

tuned tank. Then I would replace the tank and load with a resistor
that
is equal to the source resistor and see that I have the same voltage...

Alternatively, the voltage on the output side of the Thevenin sourse
resistance should be half the voltage of the generator, if the load
is truly transformed up to the Thevenin source......

Little checks like that. Perhaps you can think of others..

I am sorry if your reader gave a problem with the formatting as I
was doing the best I could with what I had..... The "Qs" in the
last formulae are all " Q squared"..

You should look these formulae up in a book , like the ARRL handbook
or some other, to understand how they are used, and practice a little
with them... I wrote a BASIC program to do Series-Parallel conversion
using them, which makes it quicker (don't know where it is, tho).

Also, I would reccommend using PSPICE to verify all these small
circuits
to see how it works and verify that you are doing it right....
It's much easier that building and measuring, and you can try stuff out
and
get a better insight.....

Andy W4OAH

Andy write:

I found an App note on the web that will
show you how to use it.


http://www.ece.utah.edu/~cfurse/micr...E/L15/L15.html

You can probly find more by doing a google search on :

" Rp Impedance Matching "

Andy,

Thanks for the link.

Regards

David

Andy wrote:
Andy write:

I found an App note on the web that will
show you how to use it.


http://www.ece.utah.edu/~cfurse/micr...E/L15/L15.html

You can probly find more by doing a google search on :

" Rp Impedance Matching "

Andy,

What did you use to measure the voltage on the top of the tank ? I have
a 300MHz scope but the probe still seems to load down the circuit being
measured.

Thanks

Regards

David

Andy wrote:
Andy write:

I found an App note on the web that will
show you how to use it.


http://www.ece.utah.edu/~cfurse/micr...E/L15/L15.html

You can probly find more by doing a google search on :

" Rp Impedance Matching "

David wrote:
Andy,

Thanks. I am using single-ended output from the SA602 as well as for the
SA605 input. I decouple the unused output/input with 100n Cap in each
case.

How do you know the match is working correctly ? My concern is that when
I build the circuit and sweep it with a sig gen and tune it for peak,
how do I know the match to is correct in the first place.

Regards

David





For RF matching and filter responses, I like to use RFSIMM99 which is an
impedance analysis program using Sparameters.

The Sparameters are generally for active devices, but it also does a nice
job with resistors, inductors, and capacitors. One trick it has is a
tolerance analysis routine using monte carlo to choose randomg component
tolerances. Very useful when testing to see if a particular circuit is
likely to be tempermental, or if it will tolerate component variation.....

Just do a websearch for RFSIMM99 and you will find the program, it is
freeware.



Jim Pennell
N6BIU



--

21:45 Pacific Time Zone
Jun 6 2006

International Time
04:45 UTC
07.06.2006

Jim,

I have RFsim99.

Do you have an example model for the filter ?

thanks

David

Jim wrote:
David wrote:
Andy,

Thanks. I am using single-ended output from the SA602 as well as for the
SA605 input. I decouple the unused output/input with 100n Cap in each
case.

How do you know the match is working correctly ? My concern is that when
I build the circuit and sweep it with a sig gen and tune it for peak,
how do I know the match to is correct in the first place.

Regards

David





For RF matching and filter responses, I like to use RFSIMM99 which is an
impedance analysis program using Sparameters.

The Sparameters are generally for active devices, but it also does a nice
job with resistors, inductors, and capacitors. One trick it has is a
tolerance analysis routine using monte carlo to choose randomg component
tolerances. Very useful when testing to see if a particular circuit is
likely to be tempermental, or if it will tolerate component variation.....

Just do a websearch for RFSIMM99 and you will find the program, it is
freeware.



Jim Pennell
N6BIU