Harold,

The chip's phase measurement transer function has a positive slope for phase
angles less than 0deg and a negative slope for phase angles greater than
0deg. So it seems to me that resolving the 180 deg ambiguity is just a
matter of knowing which slope you're on. This might be done by switching in
a small known reactive component and observing which direction the phase
output changes. Once you know which slope you're on, I think you're home
free...no??

Joe
W3JDR
"Harold E. Johnson" wrote in message
news:Yhiab.496033$Ho3.84151@sccrnsc03...
The chip you're looking at does have a 180 degree ambiguity unresolved.
Makes it tough to do the job you're asking of it. Wait a couple weeks and
look on Google for N2PK. You'll find a real vector network analyzer good
from 50 KHz to 60 MHz with narrow band application to 2 meters and 432
MHz.

W4ZCB

The chip's phase measurement transer function has a positive slope for
phase
angles less than 0deg and a negative slope for phase angles greater than
0deg. So it seems to me that resolving the 180 deg ambiguity is just a
matter of knowing which slope you're on. This might be done by switching
in
a small known reactive component and observing which direction the phase
output changes. Once you know which slope you're on, I think you're home
free...no??

Do it the way you want to.

W4ZCB

Do it the way you want to.

Harold,
I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.

Joe
W3JDR

In article ,
says...
Do it the way you want to.

Harold,
I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.


Who knows what he meant by that, but the idea of using a "line
stretching" hack to resolve the phase ambiguity sounds like a great one
to me. I'd definitely be up for building a VNA that has decent
frequency coverage and that's PC-driven. I'll take a gander at the
AD8302's specs first chance I get and see how it looks!

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

Hi, all concerned:

Everybody wants to do it in software ;o)

Telescoping brass tubes from hobby sources, or telescoping aluminum tubes
from eg Texas Towers, can be used to build physical line-stretchers. Put
the movable parts in a trough say of copper or aluminum gutter for
unbalanced apps. Plan the device parts carefully, and near-50-ohm surge
impedance can be had by purists and others.

73, Dave, N3HE

"John Miles" wrote in message
...
In article ,
says...
Do it the way you want to.

Harold,
I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.


Who knows what he meant by that, but the idea of using a "line
stretching" hack to resolve the phase ambiguity sounds like a great one
SNIP

Hi, all concerned:

Everybody wants to do it in software ;o)

Telescoping brass tubes from hobby sources, or telescoping aluminum tubes
from eg Texas Towers, can be used to build physical line-stretchers. Put
the movable parts in a trough say of copper or aluminum gutter for
unbalanced apps. Plan the device parts carefully, and near-50-ohm surge
impedance can be had by purists and others.

73, Dave, N3HE

"John Miles" wrote in message
...
In article ,
says...
Do it the way you want to.

Harold,
I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.


Who knows what he meant by that, but the idea of using a "line
stretching" hack to resolve the phase ambiguity sounds like a great one
SNIP

I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.

Joe
W3JDR

I'm just brushing you off. I wrote to let you know of another avenue to do
the job you wish to do where someone else has invested a tremendous amount
of professional work in both the hardware and software. It will be available
on the Internet in a week or so. (Several of us have enjoyed the end product
as a Beta test group for something over a year.) I don't have any time or
interest in participating in a sincere dialog.

Regards

W4ZCB

Well, I guess that settles that.
The definitive work has been done and there's no room for improvement or any
sense in discussing it further.

Thanks for your help

Joe

"Harold E. Johnson" wrote in message
news:Ierab.505021$YN5.337471@sccrnsc01...


I'm puzzled by your reply. Does it mean that you agree, or that you
disagree, or that you're just brushing me off? If it's the latter, I can
accept that too...I'm just looking for a sincere dialog about an idea.

Joe
W3JDR

I'm just brushing you off. I wrote to let you know of another avenue to do
the job you wish to do where someone else has invested a tremendous amount
of professional work in both the hardware and software. It will be
available
on the Internet in a week or so. (Several of us have enjoyed the end
product
as a Beta test group for something over a year.) I don't have any time or
interest in participating in a sincere dialog.

Regards

W4ZCB

I'm just brushing you off. I wrote to let you know of another avenue to do
the job you wish to do where someone else has invested a tremendous amount
of professional work in both the hardware and software. It will be available
on the Internet in a week or so. (Several of us have enjoyed the end product
as a Beta test group for something over a year.) I don't have any time or
interest in participating in a sincere dialog.

Regards

W4ZCB

Hi Harold,
I well recall Paul's wattmeter- well ( or even way) beyond what others had done-
the engineering and documentation was superb. Looking forward to his work on the
VNR.
I am not far from you- near Cashiers on Lake Glenville.

Dale W4OP

I well recall Paul's wattmeter- well ( or even way) beyond what others had
done-
the engineering and documentation was superb. Looking forward to his work
on the
VNR.
I am not far from you- near Cashiers on Lake Glenville.

Dale W4OP

Hi Dale, I had no idea that you were that close. Been to Glenville many
times. Why don't you come over on the first Wednesday of any month for our
QCWA lunch. We have a very active group and actually have two meetings a
month, but the first one always has an interesting program. If it poses a
problem doing it in one day, We have a great guest apartment and I'd put you
up for a Tuesday night sort of thing. You can even play with my STAR. A
little DSP transceiver
that Peter Rhodes developed. 160-10 with superb characteristics. There are 9
of those finished now, with another half dozen in various stages of
completion just in the Beta group. I have no idea how many more are being
built
as the project continues to evolve in Radio Communications.

If you liked Paul's wattmeter, you'll be blown away with what he's done with
the VNA. Documentation itself is in 3 parts and looks like a doctoral
dissertation.

Both Paul and Bill Carver were here last month (Wish I had known you were
this close! We met Alan Victor and Jim Scarlett and his son at Shelby for
lunch) and brought their VNA's along
for a round robin test. Under 1 percent variations on the Q of a test
crystal between the units. He's added software to make it perform a half
dozen other tasks, Transmission, Reflection, Group delay and some real time
stuff. I've junked my dual crystal oscillators in the quad
shield for Ip3 tests, the VNA does it on ANY frequency. A real "Lab in a
Box". I think I've run the antenna characteristics on everybody's antennas
within a
10 mile radius.

Regards

W4ZCB