Hi group,
I would like to share a quick project with you. This project is more metal work than electronics.
If you have used a network analyzer you will quickly find that you need to have a short, open and load to perform calibrations.
I found myself needing a set of BNC female calibration standards. BNC is not really a good choice for VNA, but if you are working on a project with BNCs there is little choice. Normally the calibration standards are N, SMA, APC 7 or better connectors.
This set seems to work fine at a few hundred MHz.
The BNC connector that I used is Delta Electronics Mfg.Corp 1020-000-N911-1
Here is the drawing:
These will press fit into 0.312 (5/16) hole.
SchematicIt doesn't get much simpler than that.
Connector preparationThe short was constructed by making a brass disc with a small hole and soldering the disc to the back of the connector:
The open was constructed by filing the center pin.
The load was constructed by soldering two 0805 100 Ohm 1% resistors on the connector.
HousingThe housing started as 0.6" length of 0.875" hexagonal bar stock (aluminum 6061):
Three holes were drilled into the center of the block:
Assembly The connectors were then pressed into the holes:
I gave this a quick test on my HP 3577A (5Hz to 200 MHz) VNA and they work fine.
I need to make a label.
Regards,
Jay_Diddy_B