In article .com,
john w. wrote:

Looking for suggestions / construction articles on how to make a "poor
man's network analyzer" for the HF frequency range by using either an
I/Q demodulator chip or else a precision phase & gain measuring chip
like the AD8302.

I would swear that I had seen an article on this topic someplace, about
a year ago. But I've lost the article, and I just spent several hours
of fruitless Internet searching.

Thanx in Advance! john w.


Vector network analyzer:

http://www.tapr.org/kits_vna.html?PH...75d27069f2 44
0fa7

Or, if you can't hack fine-pitch boards, you can buy it assembled and
tested: ($655)

http://radio.tentec.com/Amateur/vna

measurements:

S21 Magnitude: gain or loss of two-port network from input to output.

S21 Phase: the transfer phase of two-port network from input to output.

S11 Magnitude: return loss of one-port or two-port network referenced
to input of the network.

S11 Phase: the phase angle of return loss of one-port or two-port
network referenced to input of network.

Specifications

Frequency Range: 1 MHz-100 MHz at full specification. Operational with
degraded performance up to 120 MHz and down to 200 kHz.

Resolution:
..1 dB for amplitude measurements
1 degree for phase measurements

Dynamic Range:
in forward mode, 80 dB at lower frequencies
75 dB mid-range and higher frequencies
In reverse mode, -35 dB at lower frequencies
-25 dB at mid-range and higher frequencies

Output Power: nominal +3 dBm (approx. 2 mw) at TRANSMIT connector

Maximum Input Level: +10 dBm (2 V P-P) into TRANSMIT or RECEIVE
connector.

Requirements for host PC: Windows 98SE, 2000 or XP. Also requires
Windows installer program and .NET 1.1 framework (provided on CD) run
time package.



Not as good as the Agilent box I have in the lab, but the Agilent box
costs more than my car...

--
Namaste--