The N2PK Standalone VNA (SVNA) is based on a design by Lawrence, VE7IT. To see Lawrence's adaptation of the N2PK VNA PCB to a standalone, reflection only, VNA with its own controller and user interface, click here. |
Here are some of the changes that I made to Lawrence's design:
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A rather unique test configuration is used for transmission measurement with one detector. This configuration places the transmission DUT (T.DUT) between the RF DDS and either the RFIV Test Head or a matched Hi-Z bridge which is, in turn, connected to the detector RF Input. |
With 50 ohms as the reflection DUT (R.DUT), the transmission DUT sees a nominal 50 ohm load (as needed) and the RF DDS provides the nominal 50 ohm source impedance. At the same time, both the RFIV Test Head and the matched Hi-Z bridge provide relatively low insertion loss with the 50 ohm reflection DUT unlike the T1-6T bridge which is balanced with the 50 ohm reflection DUT present. |
For reflection measurements, a coax jumper is used between the RF DDS and the RFIV Test Head input. This coax jumper is also the transmission thru calibration standard. |
The above configuration and other features of the N2PK SVNA can be seen in the following block diagram: |
(The block diagram can be enlarged for better clarity by clicking on it in an 800x600 window or larger.) |
Here are some pixs of my N2PK SVNA (click on each to enlarge): |
If you're still reading and interested in more, click on each document or ZIP file named below to either view or download it: |
Note that these schematics are untested since there have been NO builds directly from them yet. Verify pinouts etc against other sources of info. Use at your own risk! |
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Please feel free to contact me with any comments or questions
at:
73,
Paul Kiciak, N2PK