What is the loss of this connector? CB noobie question - Page 1
Forum section: electronics / beginners

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: May 03, 2015, 12:08:22 pm
content: Hi everybody!I just wanted to know what the loss would be of this connector:http://www.ebay.com.au/itm/N-TYPE-MALE-to-PL259-MALE-ADAPTOR-PLUG-UHF-CONNECTOR-HAM-CB-SO239-ADAPTER-/201052256995?pt=LH_DefaultDomain_15&hash=item2ecfa5fae3At 477mhz (cb radio frequency in Australia). I want to use this connector so i don't wear out my so-239 connector on my radio and this is probably the lowest loss connector i could think of. So is there a better lower loss connector and what is the loss of this connector?Thanks!

author: GreyWoolfe
author_rank: Unknown
timestamp: May 03, 2015, 12:14:52 pm
content: How many times a day to you plan to connect/disconnect? I very much doubt that you will wear out the connector on your radio unless you cross thread the connector. I have 30 year old ham transceivers that the connectors look almost brand new on. Enjoy the radio and, as a friend of mine would say, don't pick flea shit out of pepper.

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: May 03, 2015, 12:23:25 pm
content: Quote from: GreyWoolfe on May 03, 2015, 12:14:52 pmI would connect/disconnect probably about 2 times a day as i will have to have the cable going through a door so when i shut the door i will have to disconnect the cableThanks

author: lapm
author_rank: Frequent Contributor
timestamp: May 03, 2015, 01:34:53 pm
content: Would be easier just drill hole for antenna cable in wall.

author: Nerull
author_rank: Frequent Contributor
timestamp: May 03, 2015, 02:12:27 pm
content: SO-239 is already pretty awful above 300MHz. The impedance drops in the middle of the connector and generates reflections. If you're worried about loss, put something else on it.

author: madires
author_rank: Super Contributor
timestamp: May 03, 2015, 02:13:08 pm
content: If the connector isn't too shabby the loss would be around 0.1 - 0.3 dB, but I would go for a high quality SO-239 with PTFE dielectric (suited for up to about 450 MHz) or a N type connector (up to 11 or 18 GHz).

author: LabSpokane
author_rank: Super Contributor
timestamp: May 03, 2015, 05:46:48 pm
content: Quote from: madires on May 03, 2015, 02:13:08 pmThat's typical insertion loss for most common RF connectors. If you're going to doing hundreds of cycles, you really should be looking at a lab duty connector. The cheapies typically are "set it and forget it" deals. The plating will likely go quickly.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 03, 2015, 05:58:17 pm
content: Connecting and disconnecting anything like that several times a day is just asking for trouble. I would put a premium on finding a solution that would keep the connections intact.If I HAD to do several cycles/day I would use something like a General Radio connector...http://www.ebay.com/itm/General-Radio-type-874-connector-to-type-N-male-adapter-/201239413811

author: madires
author_rank: Super Contributor
timestamp: May 03, 2015, 07:25:04 pm
content: Quote from: Richard Crowley on May 03, 2015, 05:58:17 pm... after asking the seller if it's 50 or 75 Ohms.

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: May 03, 2015, 09:28:15 pm
content: Quote from: lapm on May 03, 2015, 01:34:53 pmWe rent and i also dont think my mum would be very happy (i am only 14)Thanks

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: May 03, 2015, 09:38:41 pm
content: What about this connector:http://www.ebay.com.au/itm/UHF-female-SO239-jack-to-UHF-female-double-straight-RF-Coaxial-adapter-convertor-/161296121428?pt=LH_DefaultDomain_15&hash=item258dff7e54I imagine this would have more loss than the pl259 to n type or am i wrong?Thanks

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 03, 2015, 09:56:48 pm
content: "Loss" isn't really the issue. The larger issue up at 400+ MHz is the impedance mismatch through all those cable-connector-connector-connector-radio joints.The SO-239 connector on your radio is probably more rugged than ANY of the alternatives you are looking at. I think you are chasing phantoms and should just use it as-is. You have an excellent chance of making things worse.