On Dec 6, 2007, at 6:25 PM, Rick Mann wrote:
So, as it turns out, HRO had a duplexer with an N connector on the antenna side. I just need to see about changing the connector on the antenna (and actually mounting my N-connectors), and I don't have to change the connector on the radio.
My PL-259s were all silver-plated. So are the Ns, but they are not crimp-on; I'll still have to solder them. The part that gets soldered is of substantially lower mass than the PL-259, so hopefully it'll go better. Sigh.
Who's N connectors are you using?
I've seen N connectors lately that look like PL-259's and have to be soldered on similarly to RG-8 sized coax. I tried one. Pulled on the connector after soldering it together and it had zero strain-relief for the cable being pulled on, and it ripped apart. (Well, the center conductor held on as long as it could). I wouldn't use those for anything.
There's three sitting here in the connector box, and I wouldn't wish them on my worst enemy. (In fact I should throw them out but I can't -- I'm a packrat and they'll stay there for "emergencies" that will never happen, because I have a small supply of ... see below...) They were supposed to "screw on" to the jacket of the cable for strain relief, and they frankly -- didn't. The cable I was using had a pretty stiff outer jacket -- perhaps some "softer" RG-8 sized cable would have worked better, but the "soft" stuff I have (some no-name RG-213) was not high enough quality that I wanted to use it for an outdoor run.
I have switched to LMR-400 and crimp N connectors put together with a good quality crimp tool for the VHF/UHF rover station in the Jeep, and haven't had a lick of trouble from any of those cables or connectors at all, in pretty harsh vibration and movement conditions. (The cables and things aren't fully "tied down" and things move in the shelf while I'm driving... not a lot, but the cables get flexed and moved and nothing has come apart yet. A Jeep on a dirt back road is pretty bumpy too... everything gets a good "shakedown" cruise, so to speak.
I think the investment in a good quality RF connector crimp tool, the use of Amphenol or other best-quality connectors (even when they're more expensive), and the good quality cable in the LMR-400 really helps make getting the rover ready to go or make changes a snap. For a more permanent installation, the connector would just need to be weatherproofed as needed.
We've been using crimped N connectors on repeater equipment using LMR400 for jumpers (not for the run up the tower, and LMR400 has been known to cause noise in duplexed transmit and receive repeater service, so we're limiting its use to short connections indoors) with modern crimp connectors when done right with proper cable stripping tools, crimp tools, and care of workmanship, work VERY well and exhibit some better qualities to me these days over the solder-on connectors.
-- Nate Duehr, WY0X nate@natetech.com