EIP 578 microwave counter - what internal coax cable connectors are used? - Page 1
Forum section: electronics / repair

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 08:44:00 pm
content: Hello. I picked up an EIP 578 microwave frequency counter on Ebay. It doesn't count so I have started trouble-shooting it. I would like to know what type of internal mini coax connectors are used so I can get adapter cables (to SMA) for my spectrum analyzer. This allows me to troubleshoot the various inputs and outputs from the internal boards. It looks very close to SSMB connectors but the instrument is from 1984 and the SSMB was apparently not invented until 1995. So, likely, the connectors are something else. Does anyone know?Thanks/John.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 08:45:18 pm
content: More pictures

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 08:49:02 pm
content: One more picture.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 08:50:27 pm
content: Last picture.

author: TimFox
author_rank: Super Contributor
timestamp: September 30, 2020, 09:03:18 pm
content: Those look like "SMB" connectors, which are quite common in RF devices such as synthesizers, spectrum analyzers, and counters as internal coax connections. Note that they are smaller than "SMA" connectors, and snap onto their mates. I believe the SMB and SMC series have the same dimensions, although the SMC connector is threaded (like the SMA) instead of snapping.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 09:18:31 pm
content: Thanks for the response. They can't be SMB as the diameter on my connector is about 1mm smaller than SMB. Please see attached from Rosenberger catalog. Its dimensions match SSMB but I read that SSMB was not invented until 1995 and my instrument is from 1984.Thanks,/John.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: September 30, 2020, 09:37:31 pm
content: HiLooks like these are MCX connectors, an MCX is like a SMB but 30% smallerGeorge

author: John_ITIC
author_rank: Frequent Contributor
timestamp: September 30, 2020, 10:56:15 pm
content: Hi George. I looked up MCX and they look different and have different dimensions. My connector also has a slot around the 'male' outer barrel where the cable 'female' end locks into.In fact, my connector looks like the SSMB and measures the same but I was hoping that someone could positively confirm before I order some sample adapters.What makes me doubt whether mine are SSMBs are two things:1) SSMB invented 1995 (?), my instruments is 10 years older.2) The groove the cable end snaps into is in the middle of my connector, while most pictures of SSMB have it 2/3 towards the end:https://www.pasternack.com/popup.aspx?src=/images/Product/large/PE4340.jpgHowever, the above SSMB.PNG drawing shows the groover in the middle. So inconsistent...Thanks,/John.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: September 30, 2020, 11:27:57 pm
content: Hi JohnSome manufacturers like HP designed their own RF connectors (BNC for example) which subsequently became standard connectors, maybe this is the case here.and they are SSMB'sGeorge G6HIG Dover UK

author: George Edmonds
author_rank: Frequent Contributor
timestamp: September 30, 2020, 11:39:51 pm
content: Hi again JohnI can see information that says that the SSMB connector was developed in the 1960's, NOT 1995.Apparently it is identical in form to an SMB but about 30% smaller. There is a Radial catalouge on line that dimensions them.George G6HIG Dover UK

author: John_ITIC
author_rank: Frequent Contributor
timestamp: October 01, 2020, 01:47:19 am
content: Hi George. Okay, then it is most likely SSMB's in my unit. I will order some SSMB/SMA adapter cables to try out:https://www.ebay.com/itm/SMA-Jack-to-SSMB-Male-RF-cable-RG316-6-Microwave-CPE-Wireless-AP-CATV-Amplifier/274093000712https://www.ebay.com/itm/SMA-Jack-to-SSMB-L-Female-cable-RG316-6-Microwave-CPE-Wireless-AP-CATV-Router/274092997962Cheers,/John.p.s. I visited Dover many years ago (80's). I recall I came to England via the hovercraft from Calais with my parents in our Volvo station wagon. Must have been around 1983. It seems it is no longer there.https://en.wikipedia.org/wiki/Hoverspeed

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 02, 2020, 12:20:20 am
content: Hi JohnTotally off topic.Yes the Hoverspeed terminal in Dover is sadly now a thing of the past, it has been replace during the last year or so with a banana boat terminal and an extension to the Gin Palace marina. Does Dover Harbor Board know something about the UK that the rest of us do not.I have attached two pictures of what is there nowGeorge G6HIG Dover UK