SMA connectors standard terms for mount types - Page 1
Forum section: electronics / rf-microwave

author: psysc0rpi0n
author_rank: Frequent Contributor
timestamp: September 15, 2018, 10:37:44 am
content: Hello everyone.I'm needing to create a symbol and a footprint of a female SMA connector that is designated in some sites as a "End Launch Bulkhead Mount" and just as " End Launch" in some other sites.So I would like enlightenment about these mount types because I have here at home 2 connectors that doesn't match the measures stated in the following document:http://www.farnell.com/datasheets/1681616.pdfunder the section of"End Launch Jack Receptacle"with references:132255132289(BULKHEAD MOUNT)132322132270(BULKHEAD MOUNT)So my question is what is the difference or how do I differentiate a bulkhead mount from an end launch mount or are they the same? I'm confused!

author: hendorog
author_rank: Super Contributor
timestamp: September 15, 2018, 10:56:15 am
content: My understanding is this, but I have never bought bulkhead mount:* End launch = mounts on the edge of a PCB, and you need to determine PCB thickness to get the correct connector.* Bulkhead = has longer threads, and comes with a washer and a nut* Jack = female SMA

author: psysc0rpi0n
author_rank: Frequent Contributor
timestamp: September 15, 2018, 11:25:24 am
content: Quote from: hendorog on September 15, 2018, 10:56:15 amHum, ok. Can you please tell me what is a washer and a nut?

author: hendorog
author_rank: Super Contributor
timestamp: September 15, 2018, 07:03:09 pm
content: Washer:https://en.wikipedia.org/wiki/Washer_(hardware)Nut:https://en.wikipedia.org/wiki/Nut_(hardware)SMA washer and nut:https://www.dpcav.com/xcart/SMA-Nut-and-Washer-Set.html

author: mmagin
author_rank: Frequent Contributor
timestamp: September 15, 2018, 08:39:04 pm
content: Another dimension to the SMA jacks that mount on the edge of a PC board to be aware of: if you get beyond the 4 GHz range, you start to get into things that are increasingly precise about how the mate to the board, for examplehttp://www.belfuse.com/resources/Johnson/drawings/dr-142-0771-831.pdfThe lower frequency connectors just plop a big pin down on a pad on the board, the higher frequency stuff mates up to it "just so".

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: September 18, 2018, 09:28:19 am
content: Quote from: mmagin on September 15, 2018, 08:39:04 pmIn addition, if you need a high-performance design, the manufacturer usually provides models for EM simulation in something like HFSS. The annoying thing about the 'just so' footprints is that they only work for a given substrate - change the substrate material, thickness to first metal layer, etc, and the example is of no use.

author: psysc0rpi0n
author_rank: Frequent Contributor
timestamp: September 19, 2018, 07:36:35 pm
content: Quote from: mmagin on September 15, 2018, 08:39:04 pmThis will be to be used at the range of 0Mhz up to 27Mhz. So, it's far from 4Ghz! Even so, I had to be extra careful with some design details. And I'm going to re-design my first signal amplifier and make the tracks to match the 50 ohm impedance which I think, if I did things correctly will make my tracks 3.3mm wide. I'll use SMA jacks and SMA pigtails to "drive" the signal to where it needs to go across the boards I have. I have 4 different PCBs to interconnect. One of them is just a basic split supply to allow me to have +5V and -5V at home!

author: psysc0rpi0n
author_rank: Frequent Contributor
timestamp: September 19, 2018, 07:37:37 pm
content: Quote from: TheUnnamedNewbie on September 18, 2018, 09:28:19 amI hope I don't need that just because I don't even know what that is of HFSS.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: September 20, 2018, 06:13:43 am
content: Quote from: psysc0rpi0n on September 19, 2018, 07:37:37 pmDon't worry about it then, if you are doing just a few tens of MHz, all of this doesn't matter all that much.In case you are interested, HFSS is a very powerfully (and very expensive and frustrating) software suite for electromagnetic simulation. You won't need it for your application.

author: psysc0rpi0n
author_rank: Frequent Contributor
timestamp: September 20, 2018, 06:49:38 am
content: Quote from: TheUnnamedNewbie on September 20, 2018, 06:13:43 amOk. Thank you. As for frustrations, my small project has done enough on me due to my inexperience and probably also some mental laziness I can't control. Last time I was at school lab, I was testing the thing and somehow the output wave of the thing was weird only at the top of the sine wave. The bottom side was OK. I couldn't figure out what was going on. When teacher came to me to help, in not more than 20 minutes, he figured out I was bypassing a filtering capacitor and the opamp was saturating at the positive rail because the filtering capacitor was not there to remove the DC component so the top side of the sine wave was grater than the positive feeding voltage of the opamp.Sent from my SM-G935F using Tapatalk