Forums › General Discussions › sma connector on SA44b
- This topic has 7 replies, 5 voices, and was last updated 8 years, 2 months ago by Phil.
tomhParticipanttomh December 10, 2014 at 6:16 am
I need to replace the sma connector on my SA44B. Is there anything I need to look out for before I take it apart to replace it?
Justin CrooksModeratorJustin Crooks December 10, 2014 at 10:03 am
You’d need an ESD-safe work area with hot air. Be sure to get an SMA end-launch connector with the longer barrel. The internal shield will have to be removed–it is soldered down with low temperature tin-bismuth solder. And, of course, it will void any warranty you may have. If you’d like, you can send it to us for a quote instead.
PhilParticipantPhil December 10, 2014 at 1:42 pm
I know this doesn’t help your current situation, but I have found to preserve my test equipment connectors (who’s connect/disconnect lifetime is limited and well, occasionally one cross threads, etc.) the best preventative measure is to screw a male-female adapter onto the equipment connector and leave it there. That way it is the adapter that takes the abuse in the long run. In the case of the spectrum analyzer, I just keep a DC block connected to it. Double protection.
AndyParticipantAndy December 11, 2014 at 2:56 am
As soon as I got my Hound I could see the connectors being a weak spot, so I built the two units into a smart instrument case and fitted two ‘sacrificial’ SMA’s to the front panel. These are connected to the Hound’s connectors with short leads. A quick self-sweep up to 4 GHz showed no loss or dips.
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tomhParticipanttomh December 16, 2014 at 7:24 am
Thanks everyone for all the suggestions. I bent the center pin in a bit to make a better temporary connection and installed an sma to bnc female adapter. Since Mini Circuits is offering 10% off everything for the month of December, I’m going to take Phil’s suggestion and buy a couple of BLK-89+’s.
I loosened the nuts on the sma and the two bnc connectors but found that the board didn’t move freely in either direction and did not want to force. it. If someone (Justin :)) can tell me how to get the board out, I’d really appreciate it. The warranty is long since gone. I bought the SA44b just after it was released.
AndyParticipantAndy December 16, 2014 at 11:30 am
Remove the nut from the front SMA. Remove the sticky trim label from the rear panel (you may have to remove the nuts from the BNC’s) and you will see four cross-head screws. Remove these and then you can slide the pcb backwards out of the case. I found mine was stuck and needed a bit of brute force to free it.
I think the above is correct, but I’m working from memory. I bet Justin or one of the guys will put me right.
In case you’re wondering why I took mine to bits, I had blown up the mixer (still don’t know how…) and wanted a look inside.
CliffParticipantCliff January 9, 2015 at 6:58 pm
You are all addressing temporary fixes to a poor design issue that by now should have been addressed and corrected. I have had communication service monitors and spectrum analyzers in use for over 30 years and they use in most all instances the time proven indestructible N Female connector. I have never had an N connector catastrophic failure and only having replaced one due to stupidity. These small brass SMA’s are just about as worthless as the mini USB’s being push upon the industry. If I can’t take a piece of test equipment out into the field for fear of some delicate connection being problematic the device as far as I’m concerned is useless. I like my Signal Hound and fabricated an inexpensive solution without jeopardizing any warranty that enabled me the use of my beloved N type connections. The SA is currently in the field but I will have photographs of the fix took upon it’s return. I hope it comes home in one piece.
PhilParticipantPhil January 15, 2015 at 10:35 am
I will mention as to Cliff’s point – SMA connectors are usually rated for multi-100s of mating cycles where I have seen N connector specifications up to 10,000 mating cycles. Lifetime is also highly dependent upon the material quality of the connectors used and how they are treated (eg. over-tightening, rotating the cable instead of the nut, excessive vibration, coupling with connectors that have bent, excessively protruding pins, etc.) Treat your connectors with respect. If you are curious I still put male/female adapters on the N connectors on my other test gear as all it takes is a misstep while trying to connect some stiff heliax to ruin your day, be it SMA or N connector.
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