Has anyone here built a GOOD antenna/network analyzer?

From what I can determine, the MFJ stuff doesn't resolve the sign of
reactances, nor does it have a computer interface. I was looking at Analog
Devices' AD8302 IC (http://www.analog.com) for this application. This is a
single-chip device that measures the gain and phase difference between 2 RF
inputs up to 2.7 GHZ with very high accuracy. It occurred to me that this
chip, together with a PIC that has A-D conversion, and a computer-controlled
station transceiver, could form the basis for a very nice programmable
antenna/network analyzer that would run rings around the MFJ units.

Comments?

Joe
W3JDR

W3JDR wrote:

Has anyone here built a GOOD antenna/network analyzer?

From what I can determine, the MFJ stuff doesn't resolve the sign of
reactances, nor does it have a computer interface. I was looking at Analog
Devices' AD8302 IC (http://www.analog.com) for this application. This is a
single-chip device that measures the gain and phase difference between 2 RF
inputs up to 2.7 GHZ with very high accuracy. It occurred to me that this
chip, together with a PIC that has A-D conversion, and a computer-controlled
station transceiver, could form the basis for a very nice programmable
antenna/network analyzer that would run rings around the MFJ units.

Comments?

Joe
W3JDR

Hi Joe,
Look at:
http://www.njqrp.org/antanal/
Perhaps your IC could be combined with this controller.

Dale W4OP

W3JDR wrote:

Has anyone here built a GOOD antenna/network analyzer?

From what I can determine, the MFJ stuff doesn't resolve the sign of
reactances, nor does it have a computer interface. I was looking at Analog
Devices' AD8302 IC (http://www.analog.com) for this application. This is a
single-chip device that measures the gain and phase difference between 2 RF
inputs up to 2.7 GHZ with very high accuracy. It occurred to me that this
chip, together with a PIC that has A-D conversion, and a computer-controlled
station transceiver, could form the basis for a very nice programmable
antenna/network analyzer that would run rings around the MFJ units.

Comments?

Joe
W3JDR

Hi Joe,
Look at:
http://www.njqrp.org/antanal/
Perhaps your IC could be combined with this controller.

Dale W4OP

The technology has been available for several years to enable a manufacturer
to produce a reasonably priced, small, hand-held, battery-operated, antenna
analyser which displays the sign of jX.

But the manufacturers have not yet extracted all that's available from the
market. Its too early to introduce a new model which would outclass the old.

What is needed in the market is a new manufacturer who has no history to
take advantage of.

Chinese ?

The technology has been available for several years to enable a manufacturer
to produce a reasonably priced, small, hand-held, battery-operated, antenna
analyser which displays the sign of jX.

But the manufacturers have not yet extracted all that's available from the
market. Its too early to introduce a new model which would outclass the old.

What is needed in the market is a new manufacturer who has no history to
take advantage of.

Chinese ?

Dale,
Actually, I was thinking that the controller is a PC or laptop. It would
control the station transciever as a swept low-power frequency source, and
get the phase and gain readings from the PIC that would be paired with the
Analog Devices part (and of course a directional coupler of some sort...even
a simple bridge would suffice). This design could result in a very simple,
low-cost, and powerful vector network analyzer for the average ham.

Joe
W3JDR


"Dale Parfitt" wrote in message
...


W3JDR wrote:

Has anyone here built a GOOD antenna/network analyzer?

From what I can determine, the MFJ stuff doesn't resolve the sign of
reactances, nor does it have a computer interface. I was looking at
Analog
Devices' AD8302 IC (http://www.analog.com) for this application. This is
a
single-chip device that measures the gain and phase difference between 2
RF
inputs up to 2.7 GHZ with very high accuracy. It occurred to me that
this
chip, together with a PIC that has A-D conversion, and a
computer-controlled
station transceiver, could form the basis for a very nice programmable
antenna/network analyzer that would run rings around the MFJ units.

Comments?

Joe
W3JDR

Hi Joe,
Look at:
http://www.njqrp.org/antanal/
Perhaps your IC could be combined with this controller.

Dale W4OP

Dale,
Actually, I was thinking that the controller is a PC or laptop. It would
control the station transciever as a swept low-power frequency source, and
get the phase and gain readings from the PIC that would be paired with the
Analog Devices part (and of course a directional coupler of some sort...even
a simple bridge would suffice). This design could result in a very simple,
low-cost, and powerful vector network analyzer for the average ham.

Joe
W3JDR


"Dale Parfitt" wrote in message
...


W3JDR wrote:

Has anyone here built a GOOD antenna/network analyzer?

From what I can determine, the MFJ stuff doesn't resolve the sign of
reactances, nor does it have a computer interface. I was looking at
Analog
Devices' AD8302 IC (http://www.analog.com) for this application. This is
a
single-chip device that measures the gain and phase difference between 2
RF
inputs up to 2.7 GHZ with very high accuracy. It occurred to me that
this
chip, together with a PIC that has A-D conversion, and a
computer-controlled
station transceiver, could form the basis for a very nice programmable
antenna/network analyzer that would run rings around the MFJ units.

Comments?

Joe
W3JDR

Hi Joe,
Look at:
http://www.njqrp.org/antanal/
Perhaps your IC could be combined with this controller.

Dale W4OP

Reg,
I don't think it has much to do with planned product lifecycle...it's just
inertia and complacency. Nor do I don't think there's enough volume for a
"Chinese" manufacturer.

I think the main reason we haven't seen something better is that it's too
small a market for a startup to tackle. It's definitely a product for a tiny
company.

Joe
W3JDR

"Reg Edwards" wrote in message
...
The technology has been available for several years to enable a
manufacturer
to produce a reasonably priced, small, hand-held, battery-operated,
antenna
analyser which displays the sign of jX.

But the manufacturers have not yet extracted all that's available from the
market. Its too early to introduce a new model which would outclass the
old.

What is needed in the market is a new manufacturer who has no history to
take advantage of.

Chinese ?

Reg,
I don't think it has much to do with planned product lifecycle...it's just
inertia and complacency. Nor do I don't think there's enough volume for a
"Chinese" manufacturer.

I think the main reason we haven't seen something better is that it's too
small a market for a startup to tackle. It's definitely a product for a tiny
company.

Joe
W3JDR

"Reg Edwards" wrote in message
...
The technology has been available for several years to enable a
manufacturer
to produce a reasonably priced, small, hand-held, battery-operated,
antenna
analyser which displays the sign of jX.

But the manufacturers have not yet extracted all that's available from the
market. Its too early to introduce a new model which would outclass the
old.

What is needed in the market is a new manufacturer who has no history to
take advantage of.

Chinese ?

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