On Thu, 09 Nov 2006 15:00:25 -0800, Roy Lewallen
wrote:

MAc wrote:

I was thinkink about it, but i want to do it "as much analogue as
possible" ;-)

You'll get some good ideas from "The Tandem Match - An Accurate
Directional Wattmeter" by John Grebenkemper, KA3BLO, in Jan. 1987 QST.
See also corrections to the article in Jan. 1988 Technical Correspondence.

Also he

http://n2pk.com/RLPmtr/RLPv1c.pdf

xpyttl napisa³(a):
If you're going to be doing the math anyway, analog or digital, and
providing some sort of calibration mechanism, you don't need to get too
weird about the directional coupler.

DC (coupler) isn't a problem for me. I've made few reflectometers (both
HF and VHF) based on homebrew couplers. I've tested toroids, pcb's and
copper tubes.

I am rather afraid (terribly afraid) about mistakes in my op-amp
mathematics ;-)

Now I'm thinking about ad 8302, 8307 and also (used in my FSM - ad8313)

MAc
sp9mrn

Wes Stewart napisał(a):


http://n2pk.com/RLPmtr/RLPv1c.pdf


N2PK wrote ~~"...measure return loss instead of swr..."
I think, its the best way.
I suppose (only for "comparisom" purposes) I can make a second scale on
meter face which will show swr (N2pk article figure2)

MAc

"MAc" wrote in message
...

I am rather afraid (terribly afraid) about mistakes in my op-amp
mathematics ;-)

Don't be afraid ... just fudge it!

...

So, the way is 2x AD8310 +dual opamp and analog meter.
Will report the result. Now I'm waiting for parts.

Thanks to all

73
MAc
sp9mrn