Ian, G3SEK wrote:
"You are now going to claim that an SWR meter contains a section of
transmission line."

At VHF where the wattmeter may affect SWR, it is customary to make the
meter plus its cable extension into 1/2-wave so that its insertion and
removal nave minimum effect.

Best regards, Richard Harrison, KB5WZI

I am not going to go around in circles on this. The now obsolete Motorola RF
manual is still a good source for the real world. As for the noise figure,
it is a well known fact that best NF and maximum gain do not coincide.

Tam/WB2TT
"Dr. Slick" wrote in message
om...
"Tarmo Tammaru" wrote in message
...
"Dr. Slick" wrote in message
om...
(Tdonaly) wrote in message
...
Zo doesn't have to be the coax impedance. It can be any impedance
you want. What about interstage-matching networks between FETs? Do
you think there are no reflections there? Should you attempt to match
impedances there? I would think so.

You transform the input impedance of the driven stage to the optimum
load of
the driving stage. Whether that results in a conjugate match is
completely
immaterial. Trust me, I have done it .



Oh really? Did you use MIMP? or ADS? How did you design your
interstage matching network? what did you start off with? How do you
know a conjugate match didn't matter? What transistors did you use?
Can you show us the data sheets?

Can you show us your design notes please?



As for the Zo thing, you are trying to misapply the formula.

BTW, the one place where you would think conjugate matching should
always
apply, antenna to receiver input, does not (always). Lowest noise figure
often occurs at SWRs around 1.5

Tam/WB2TT


Nope. Zo can be anything you want, especially interstage where
you usually don't have/need a 50 ohm transmission line.

Who told you about the lowest NF at a 1.5 SWR? Can you give us a
link?

Why would reflected power at the receive end benefit NF?


Slick

"Tarmo Tammaru" wrote in message ...
I am not going to go around in circles on this. The now obsolete Motorola RF
manual is still a good source for the real world. As for the noise figure,
it is a well known fact that best NF and maximum gain do not coincide.


That's what i thought. You've never designed anything in your life.


Slick

"Dr. Slick" wrote in message
om...
That's what i thought. You've never designed anything in your life.


Slick

I just don't buy into your BS. The one transmitter was for 6m SSB, and was
good enough to work Alaska from FN20. The other was a 6m linear amp of which
about 200 were built. Now, do you want to tell us who the hell you are?

Tam/WB2TT

"Tarmo Tammaru" wrote in message ...
"Dr. Slick" wrote in message
om...
That's what i thought. You've never designed anything in your life.


Slick

I just don't buy into your BS. The one transmitter was for 6m SSB, and was
good enough to work Alaska from FN20. The other was a 6m linear amp of which
about 200 were built. Now, do you want to tell us who the hell you are?

Tam/WB2TT


Someone who has helped design more output matching networks than
you, that's certain.


Slick

"Tarmo Tammaru" wrote in message ...
"Dr. Slick" wrote in message
om...
That's what i thought. You've never designed anything in your life.


Slick

I just don't buy into your BS. The one transmitter was for 6m SSB, and was
good enough to work Alaska from FN20. The other was a 6m linear amp of which
about 200 were built. Now, do you want to tell us who the hell you are?

Tam/WB2TT


Someone who has helped design more output matching networks than
you, that's certain.


Slick

(Richard Harrison) wrote in message ...
Dr. Slick wrote:
"Does the SWR change as you change the source impedance?"

"SWR" as Reg notes is an indication of match condition when measured at
the transmitter output. There may not be enough line for maxima and
minima.

Loading a transmitter usually increases the current drawn by the final
amplifier. This lowers
its output impedance in most cases. As "SWR" is an indication of
mismatch, you can`t change one impedance without changing the "SWR",
unless you make a corresponding change in the other impedance in the
match. Corresponding is a significant word.

Best regards, Richard Harrison, KB5WZI


Well, like i said, the SWR will change as you change the source
Z, but you have to measure it before the reflection occurs (the SWR
must be the same Z as the source, and must be right at the output), or
you won't measure it "downstream".


Slick

Tam, I hope you don't allow yourself to be pushed around by this bully.
Your postings are relevant, welcome, and stand by themselves. There's no
need for any of us to justify ourselves to the likes of a person who's
too embarrassed and insecure to even reveal his name. What we post is
either true or it's not, and its truth doesn't depend on what we have or
haven't designed. Questioning a person's credentials is simply a way to
deflect attention from the questioner's inability to present a rational
counter-argument. And a person who won't even reveal his name demanding
that someone else jump through hoops to satisfy his demands for
credentials? That's laughable. Sad, but laughable.

Roy Lewallen, W7EL

Dr. Slick wrote:
"Tarmo Tammaru" wrote in message ...

Someone who has helped design more output matching networks than
you, that's certain.


Slick

I didn't *help* design anything. I designed the transmitter from mic input
to ant output.

Tam/WB2TT



Bull**it! Show us your design notes if this is true!


Slick

This is proof that the Californian artist Garvin Yee, who styles himself
as a doctor and yet is not in the amateur radio data base, does not know
what he is talking about. He may well be just a "troll."
It is indeed a well know fact that best NF and maximum gain are not
expected to coincide. Those of you who have been reading the group for
a while will remember my story about proving this to Prof Kraus when I
was his student.
Mr. Yee should play somewhere else.
Mac N8TT

--
J. Mc Laughlin - Michigan USA
Home:

"Dr. Slick" wrote in message
om...
"Tarmo Tammaru" wrote in message
...
I am not going to go around in circles on this. The now obsolete
Motorola RF
manual is still a good source for the real world. As for the noise
figure,
it is a well known fact that best NF and maximum gain do not
coincide.


That's what i thought. You've never designed anything in your
life.


Slick