SMA Connectors with Circlips @ 5.8 GHz

[VK4GHZ]

Hi all

Have you come across these SMA connectors before?
I haven't.

This is a 5.8 GHz quad patch antenna.



The outer body of the SMA is held in place with a circlip arrangement.



As a result of over tightening with 5/16" spanner, the connector "broke" apart, where the circlip arrangement became apparent.


I would have had doubts about this at 5.8 GHz, but I measured return loss @ 21dB yesterday indicating, overall, it wasn't too bad.

One option is to cut it off, and fit a regular SMA that we are all familiar with.
(ie, a solder bead around the UT141 entrance)

Thoughts on the circlip?

[VK3XDK]

Hi Adam,
some of the "cheaper" sma's have a similar arrangement.
My suggestions are- do not over tighten, they seem to be OK with a firm finger tight in most cases and bear in mind they are probably only "Chinese military spec" )
Strangely enough- some of my crap and cheap Chinese adapters have tested less losses at 10ghz than some of my "real brand stuff"

[VK3BJM]

G'day Adam.

I do have a few of these, which I obtained from Alan VK3XPD about 15 years ago. I have about 6 left unused from a packet of 20 or so, IIRC.

They weren't/aren't cheap and nasty, so the use of the circlip doesn't necessarily signify that "quality". Could just be coincidental... They are a bit of a pain to assemble, though, which is not something usually said about SMA plugs.

A small torque wrench is a handy thing for use with SMA connectors. I was lucky enough to find this purpose-built one years ago, but perhaps Kinchrome or the like have an adjustable one that would do the job?

According to the label on the handle, the torque setting is 6kgf-cm...

Otherwise, finger-tight plus 1/8th to 1/4 further with a wrench.

73,
Barry
VK3BJM

[VK4REX]

Hi Adam

You have demonstrated the reason a "open spanner" shouldn't be used.

For info you either need an adjustable torque spanner or 2 separate torque spanners as there are differences between brass and stainless connectors.

I keep 2 here one at a setting of 4 inch/pounds for brass connectors and one at 8in/pounds for stainless connectors.

Well worth the investment in ensuring connectors are not damaged and for good microwave connections

http://www.microwaves101.com/encycloped ... tor-torque

Rex