BNC Plug Price - Page 1
Forum section: electronics / general

author: girishv
author_rank: Regular Contributor
timestamp: August 31, 2020, 08:53:28 am
content: I was looking for 50ohm BNC connector(Plug). I came across this connector from TEhttps://www.te.com/global-en/product-2-5329445-1.htmlThese plugs costs US$16.30 @100 Nos. Why are these plugs so expensive compared to the ones we find in Ebay or AliExpress?

author: Fraser
author_rank: Super Contributor
timestamp: August 31, 2020, 09:04:49 am
content: Quality, Quality, Quality

author: BravoV
author_rank: Super Contributor
timestamp: August 31, 2020, 09:14:44 am
content: Not BNC, but N plug converter as example, Aliexpress vs genuine Amphenol, price wise probably 10 times or even more last time I checked.Take a look of my two N plug converters below, Aliexpress vs Amphenol.Forget about the metal, material used and finishing quality, just thru bare eyes, see the different ?

author: girishv
author_rank: Regular Contributor
timestamp: August 31, 2020, 10:49:02 am
content: Quote from: BravoV on August 31, 2020, 09:14:44 amI can definitely see the difference. Thanks.

author: Fraser
author_rank: Super Contributor
timestamp: August 31, 2020, 11:10:31 am
content: Where RF connectors are concerned there are characteristics that need to be right in a connector and these can vary in importance depending upon the scenario, frequencies involved etc. When you buy a well known brand connector that has a specification published for it, you normally receive a part that meets or exceeds that specification. When buying ‘cheap’ connectors you can receive something that looks right, but does not perform as expected. This can take the form of impedance mismatches, intermittent conch or higher insertion losses. Some connector types are constant impedance designs for demanding applications. Cheap copies are often not as accurate in terms of constant impedance and other electrical characteristics.Then there is durability. Some cheap connectors look good with their flash gilded centre pin but I gave seen the ‘gold’ flake off during use and float around in the mating connector which is not good. If connecting a cheap connector to a high quality connector on an expensive piece of test kit, you risk not only degrading performance, but also damage to the very expensive connector on the test kit. Sacrificial ‘socket protectors’ can be bought to prevent damage to the test gear but they are not cheap either.I find the best option is to buy branded connectors for demanding applications and limit my use of cheap connectors for less demanding tasks where precision is not needed.Where 50 Ohm or 75 Ohm terminations are concerned, the connector quality is one factor but the quality and type of termination resistor is another. To achieve a quality termination with relatively flat frequency response, requires a low inductance resistor type. When you buy a cheap 50 Ohm BNC termination and find a cheap 56 Ohm metal film resistor inside it..... you know it is not going to be a great part to use where VSWR and impedance accuracy is important !Good quality connectors are expensive but you can sometimes find new old stock at decent prices on eBay and they can be a very good option. If they are silver plated they can discolour but they still work fine and are far better than cheap chrome plated connectors. It is very much a case of horses for courses so the scenario dictates the risks associated with using cheap ‘no-name’ connectors. They are adequate in many less demanding roles but be aware of their limitations.Fraser

author: TimFox
author_rank: Super Contributor
timestamp: August 31, 2020, 01:32:42 pm
content: If you compare the lower-price Amphenol "RFX" BNCs (good enough for most purposes) to Amphenol's full-price mil-spec BNCs, there are two important differences:RFX is die-cast metal, mil-spec is machined.RFX has a Delrin insulator, mil-spec is Teflon.

author: Fraser
author_rank: Super Contributor
timestamp: August 31, 2020, 04:10:03 pm
content: Talking about insulators, I have seen many cheap connectors using polythene !Fraser

author: TimFox
author_rank: Super Contributor
timestamp: August 31, 2020, 06:37:18 pm
content: I haven’t seen polyethylene insulators on coax connectors for a long time, but polyethylene dielectric on coaxial cables is common. The only problem with polyethylene is its low service temperature; it has reasonable dielectric constant and low dielectric loss.