The ones that are in that cheap RS-70 Watt meter that doesn't work has a semi sort of air line.
I used some lowish end N adapters I have and tried to compare them with the two N to UHF adapters using the LiteVNA. Started out calibrating the VNA from 50k - 8G. I then took a baseline measurement.
Next an SMA male to N male, N female barrel, N male SMA female was inserted.
Last, the N female barrel was replaced with the two N to UHF adapters which were connected with an Amphenol UHF female barrel.
We can see from the TDR plot, the impedance of that UHF mess is very unstable and reaches about 27 ohms. FWHH is about 30mm, which oddly enough is about the length of that UHF mess.
If I plot S21, at 500MHz the loss with the UHF mess is about 0.4dB.
Conclusion, UHF connectors make a poor mans Betty standard
