Another gotcha (that is really really expensive) are the 50 ohm female loads that came in 3.5mm cal kits made by HP. They contain super tiny "fingers" inside that help with the match. One flinch while mating that results in accidentally spinning the female connector will ruin these instantly.
btw, I *highly* recommend investing in a set of connector gauges for SMA and up. I have a set of 3.5mm gauges in my VNA cal kit, and I also have a set of SMA gauges (these are 4 gauges since you also have two gauges for the dialectric).
Sean
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On Sun, Jan 31, 2021 at 02:07 PM, Tom Lee wrote:
Thanks for being ¡°that guy¡±. Not being aware of the difference can cause
expensive damage, and it¡¯s one of my pet peeves.
The two connectors can mate, but the 3.5mm connector is made to much tighter
tolerances. It also has an air dielectric. Mating to a poorly made (or badly
abused) SMA can wreck a 3.5mm connector¡¯s ability to maintain low SWR all
the way out to its TEM limit. Permanent damage can be done by a single
connect-disconnect cycle.
I have sacrificial connector savers on all of my expensive gear, but
occasionally a student will remove them ¡ª against the rules ¡ª to shorten a
path or because they think the savers are introducing some artifacts. If they
then connect a random SMA cable to the gear, those students have their lab
access cards deactivated pretty quickly.
¡ª°ä³ó±ð±ð°ù²õ
Tom
Sent from my iThing, so please forgive typos and brevity.
