Thank you for opening my eyes to the various ways of calibrating for non-insertable devices. Much of what you generously shared is above my paygrade, so to speak. So, I plan to re-read your post several times in the hope of gleaning more knowledge from your information-dense reply.
Moving forward, I wish the connector discussion will focus on enabling the nanoVna to live up to the "vector" in its moniker because if the phase measurement of a DUT with same-sex connectors (non-insertable device) is rubbishy, then the usefulness will drop to that the "scalar" level. Furthermore, with true 2-port VNAs in the pipeline by both Gabriel & "a member of the V2 team", developing a non-insertable calibration technique should assume greater importance.
.....They are not exclusive to APC7
though. The nicer 3.5mm calkits e.g. tend to come with a matched set of f-f,
m-f and m-m adapters. Even used these adapters still go for a pretty penny
The above paragraph startled me enough to make me check at Keysight website. Indeed, as you correctly claimed, the current 85033E 3.5 mm calkit does include options 100/200/300 for matched f-f, m-f and m-m adapters. However, rolling back to just one earlier revision, to the 85033D, these options didn't exist. Instead, APC-7-to-3.5 adapters were included for measuring non-insertable devices. Likewise, the 8753ES VNA was sold together with a N calkit (85032B) that has APC7-to-N (m/f) adapters, explicitly for use with non-insertable devices. My point is, until fairly recently, APC7-based "swap equal adapters" was the dominant technique for sub 6GHz VNA. (digression: subsequently, e-Cal came along and freed us from learning calibration!)
:-) If the APC7 equiped nanoVna fails to materialize, my backup plan is coincidentally somewhat similar to your above recommendation - swap between 83059B (f-f) & 83059C (m-f) 3.5mm adapters. I know they aren't phase matched, but judging from their physical lengths, I hope they are close :-)
I am interested in non-insertable devices calibration techniques that are suitable for the nanoVna. If you feel the "offline" unknown-THRU cal is doable by dedicated hobbyists, please consider documenting the steps for us to follow. Thanks.
Leong, 9W2LC
