On 3/22/07, Gary Schafer <[EMAIL PROTECTED]> wrote: > If you really want to get picky use only N connectors and not even bnc. A > bnc is not a constant impedance connector either although somewhat better > than a PL259. Yes I know you can plug an N connector into a bnc but the bnc > still is not a constant impedance device.
Could you site a credible source that claims this? I can't find any references to impedance regarding BNC connectors. I've stayed out of the debate so far, but even Amphenol claims "nominal 50 ohm impedance" for their 50 ohm BNC connectors up to 4 GHz. On their N-connector they drop the "nominal" but they don't elaborate. They also say the BNC has "low reflection" below 4GHz... and their N connector specifications show nothing at all regarding that. The assumption here would be the N is slightly better again. And they show that you have to switch to a TNC for anything above 4GHz through 11GHz. Or the N again, of course. I'll agree that maybe a BNC is not as good as an N-connector overall, but similar to your argument -- I'll bet no one here can measure the difference at VHF/UHF. Amp shows (much!) more RF leakage from a BNC than an N (which would be a detriment in some installations!), insertion loss numbers that are within .05 dB of each other, and the center conductor also has a slightly higher resistance on the BNC vs. the N. If I missed anything there, here's their links: http://www.amphenolrf.com/products/bnc.asp http://www.amphenolrf.com/products/typen.asp But again, just like your comment about the PL259's... I would love to see a credible source on impedance measurements of BNC's that's available to the public. Don't worry, I'm not defending the BNC -- I'd rather not use them myself. Just playing devil's advocate on the statement, since it doesn't have any more credibility or science behind it than the PL259 comments did. I *can* find credible sources that show PL259's generally stink with real measurements at VHF/UHF... but I haven't been able to find such data for BNC's (yet). And judging by Amphenol's site, TNC's keep up pretty well with the N connector. Nate WY0X
