Identify S something mini microwave connectors  - Page 1
Forum section: electronics / testgear

author: wd5jfr
author_rank: Regular Contributor
timestamp: March 10, 2023, 09:17:44 pm
content: I've haveseveral of these female jumper cables that I would like to use to set up a test board but I can't find what they're called and where to buy at a reasonable price male plugs with circuit board mounts and if there is such an item solderable cable ends. The upper middle one doesn't have an outer shield and I have only one of those. Thanks in advanceThanksHank

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2023, 09:27:04 pm
content: That looks like series "SMB".These are often found connecting modules within RF test equipment.The right-angle connectors in the photo are actually easier to wire than are the straight cable connectors.The unshrouded one looks like someone excised the outer shroud from a normal SMB connector.

author: wd5jfr
author_rank: Regular Contributor
timestamp: March 11, 2023, 12:27:17 am
content: Hey TimI took out my mag glass and it looks like the outer shield on the middle SMB connector was removed or fell off. I could see knurled ridge which was for a press fit of the outer collar. This yellow coax is braided silver double shield and the center conductor is a solid wire about 0.012" in diameter and outer diameter is about 0.102" using my drill gauge. I hope this cable and SMBs aren't 75 ohm. I tried to get L and C readings on a 30" piece but it's difficult to get a good connection without a male connector. Will have to sort thru my junk boxes or luck out at next hamfest. I've included a pic of a piece stripped back anti may be beyond my 82 year old to make good connections, but I'll try. Can anyone ID the coax?Hank

author: coromonadalix
author_rank: Super Contributor
timestamp: March 11, 2023, 01:04:22 am
content: smb series connectorshttps://www.rosenberger.com/products/connectors-adaptors/rf-connectors/

author: wd5jfr
author_rank: Regular Contributor
timestamp: March 12, 2023, 12:26:04 am
content: Thanks for Rosenbeger URL. Good info but I'll have wait to find some on the used market.Hank

author: coromonadalix
author_rank: Super Contributor
timestamp: March 12, 2023, 05:02:00 am
content: i would use SMA instead less complicated to use and build, you have tons of possibility / adapters / cables types etc ...

author: TimFox
author_rank: Super Contributor
timestamp: March 12, 2023, 02:44:51 pm
content: Quote from: coromonadalix on March 12, 2023, 05:02:00 amAs I said above, the right-angle SMBs are easier to assemble than the straight SMB plugs.We used a cheaper series for systems at < 100 MHz from E F Johnson (now Cinch) that were mechanically compatible but not guaranteed to GHz frequencies.They also made a similar frequency-derated series of SMA-compatible connectors.Note that the 75-ohm SMBs are a bit larger and will not mate with the 50-ohm connectors.Obviously, some applications prefer the SMBs to SMAs since the SMB is smaller and snaps in place.

author: wd5jfr
author_rank: Regular Contributor
timestamp: March 12, 2023, 05:29:18 pm
content: Speaking of the devil and after a bit of soul searching based on the recommendations here and what I have since found I think I will have to be flexible since I located some Rosenbergers SMA jumpers (not very flexible) but less work. But I will keep looking unenthusiastically for SMB for the flexibility of the yellow mini-coax.. The Rosenberger RTK 57E isn't very flexible! Can anyone recommend any low cost domestic or Chinese SMBs that are good enough for occasional use? BTW, I found my wire gauge and the center conductor in the yellow coax is No. 29 wire.ThanksHank