Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

SMA FEMALE to K MALE connection

Not open for further replies.


Member level 2
Sep 14, 2021
Reaction score
Trophy points
Activity points
What would go wrong if I connected an SMA male to a K male?

In the title you say SMA Female but in the text SMA male - which is it?
Not that it really matters as the real question is what is the frequency of the signal that you are dealing with?
SMA connectors are intended for high frequency RF signals. The central sire is surrounded by the outer sheath, just as it is for a coal cable. Also they are designed for 50 Ohm impedance which means that they match the impedance of the coax (assuming that you are using 50 Ohm coax of course).
I don't know what the K connectors are intended for but I suspect NOT RF signals. Also they look symmetrical (only by the images I can see I can Google search so I could be wrong) in which case you can easily swap the signal and shield paths if you are not careful.
Therefore the 'what could go wrong' includes high signal loss (impedance mismatch), and possible damage to the signal source (if the K connector is reversed then it could end up driving into the 'ground' at the other end).
The big question to you is "WHY"? Why do you want to do this?

If you connect an SMA 3.5mm connector to a K 2.92mm connector, the center pin on the 2.92mm socket will be over stressed, so that the next time you try fitting a 2.92mm plug the contact will be loose.
Anytime one starts mixing connector types a great deal of caution is generally appropriate. Performance usually degrades and sometimes the connectors are damaged. provides useful guidance. I would point you to their connector page and also suggest that you read the page on "How to trash a cal kit", as it is really about connector concerns. In some cases it is possible to mate different connector types but it rarely is a desirable situation, particularly when the connectors are expensive and high performance is desired.

I'd imagine that there exist "K to SMA" bullet adaptors. But
also imagine this is a question born of inconvenience.

I was curious about Mr. Freebird's comment above and simply searched on "SMA to K adapters". I found a number of "commercial" suppliers with offerings.

I repeat my warning: Use with caution. This is without knowing the specific situation and it may be acceptable.

Not open for further replies.

Part and Inventory Search

Welcome to