N NE1?

[K6JEK]

Alas, a lot of the old, weather exposed (and gardener exposed) coax is now junk. In contemplating new stuff I wonder why I am sticking with PL-259's

I just watched the DX engineering video for using their tool for N installation.  It looks like a snap and I'd be left with a better connector, weather resistant and all that.

Any of you using N's?

http://www.dxengineering.com/images/video/UT80N.wmv

[Steve - K4HX]

Other than the WX resistance, the N connector is no better the the 259 for HF use. And only the connection of the N is WX proof. Water can still get into the cable via the cable/connector interface.

[Pete, WA2CWA]

I only use the N connectors on the VHF and UHF stuff. All my HF rigs and HF baluns have SO-239's.

[W0BTU]

N connectors are for 220 MHz and above. Below that, forget it.

PL-259's are the way to go for anything under 220 MHz. And they will handle a lot more power than N's will even with higher SWR.

You have to be really careful assembling N plugs, constantly watching the distance between the center pin and the end of the connector. It's critical. If they stick out too far, they'll jam against the female socket and damage it. If they don't protrude far enough, they won't contact the socket pin enough (if at all!). This is a direct function of the coax center conductor length, which is just too critical.

And that's not the least of the issues. In cold weather, the center conductor in an N plug can contract and pull the center contacts apart. I always used N connectors that 'captivated' the center pin. That's supposed to prevent that, but the captivating washers are made from Teflon, which can cold flow, and they don't fix the issue above.

I don't plan on using N connectors for anything below 220 MHz again. They are just plain unnecessary at two meters and below.

If you want waterproof connectors, then stretch-wrap the PL-259's with electrical tape after you fill them with silicone dielectric compound.

There's always the "un-connector". If you won't need to disconnect the coax, then simply leave the connector out of the equation and solder (or crimp) direct. I've seen the weak-signal EME people do that at 144 Mhz.

I've seen UHF connectors used at MF at the 10 kW power level, continuous duty. I would never trust the flimsy N connector center conductor to hold up under those circumstances.

[K5UJ]

N seems to be more standard in commercial use for 1/2 inch and larger heliax.  You may have to use them if your feedline is LDF4-50A or larger because Andrew no longer makes the hardline UHF connectors.  I use them only because of that, with adapters to UHF and have had no problems.  My feedline connectors and splices are not buried--maybe that's why.  In another thread you said your feedline is 300 feet long.  If it has to be that long and you have problems with it being exposed to the elements and damage then it might be worth investing in a run of LDF4-50A.  It is expensive now but you just about have to try to damage it, it is so rugged. 

For 300 feet at 29 MHz the matched loss is a little over 1 dB.  100 watts in will deliver almost 80 watts to the load. 

300 feet of the 9913 type Belden foam RG8 that is popular with hams exhibits a matched loss of a little over 2 dB.  100 w. in will deliver 63 w. to the load.   

RG213 loss is over 3 dB, like what you have now.  47 watts to the load.   

Lots of hams balk at Heliax but you have to keep in mind these numbers are for an ideal setup--usually the load Z is not 50 ohms and there are other losses in addition to the feedline that may be harder to reduce.  Using lower loss feedline is one easy way to improve the performance of the system.  May help on receive too.  To be honest, for a run that long on 10 meters, I'd go with 7/8" heliax if I could afford it.   

Then your matched loss would be 0.57 dB with 88 watts out of your hundred making it.  That's decent. 

But maybe you use a balanced antenna like a dipole on 10.  A link coupled tuner to a balanced 600 ohm line over the ground on PVC support poles with a gentle bend up to the dipole feedpoint will give you a vswr of 8:1 if the dipole Z is 75 ohms.  the total loss of such a line 300 feet long with an 8:1 vswr is a little over 1.1 dB so 77 watts out of your transmitter 100 get to the dipole.  That's about the same performance as LDF4-50A, the half inch heliax and probably a lot less expensive. 

[Todd, KA1KAQ]

Some of the A Line Collins gear used N connectors, like the KW-1 and the 75A-4. Have also seen A-4s with BNC connectors. I recall the VHF/UHF guys swearing by them back in the 80s.

Those nice Bird Coaxwitches use the N as well, probably intended mainly for VHF/UHF or commercial use. My eventual aerial network will incorporate several of these, which means (re)learning how to install them properly.

But as others have said, the good ol' PL-259 is tough to beat at HF, for ease of use if nothing else.

[WA3VJB]

Type N really are a PITA and the only place I use them are on pre-made cables I got at Dayton to connect a wattmeter which happens to have N connectors.

For coax runs and general interconnection, the hot ticket is the silver-plated, Teflon insulator type of  PL259.

The silver takes solder quicker than the nickel types, which means less heat to damage the coax center insulator.

The Teflon around the pin seems like a better dielectric than the plastic or old Bakelite varieties.

To deal with moisture at PL259/barrel/SO239 connections, the stretch-wrap weatherproofing stuff, covered with good electrical tape, or the plyable "coax-seal" type of material, also wrapped in good electrical tape, has protected the coax from water migration over a period of years.

[W0BTU]

Some of the A Line Collins gear used N connectors, like the KW-1 and the 75A-4.

So did the directional coupler on the Collins 312B-4 station console. I replaced mine with good-quality SO-239s years ago.  Not one of Arthur Collins' better ideas.

But as others have said, the good ol' PL-259 is tough to beat at HF, for ease of use if nothing else.

Exactly right.

[KB2WIG]

Ya gotta use the expensive conectors. Paying less than $5 for a 'new' '239 is foolish; the stuff is almost always crap.

Plastidip or whatever its called, is good. I'll wrap it in Scotch 33, or better yet 88, and then coat it. You wrap the connector with the tape, slobber the dip over it and thar you ar. Fun times. 

Yeah, don't drag the coax and try to support it on its way.


klc

[The Slab Bacon]

Why is it that so many are scared szhtless of putting connectors on coass cables? ? ? ?  

PL-259s are scarey, and N's and BNCs are just terrifying       
Geeze, If you cannot at least slobber a pl-259 onto a piece of coass, you dont deserve to hold an amateur lisence! !

And.........ERR.............Furthermore, N's are actually easier to do than Pl-259s
(albeit, a bit more expensive) but all you have to slobber is the center pin. 

Back when I was a lowly novice, a local ham that was an extra and a VE used to bring me all of his cables to put the connectors on for him. WHAT IS WRONG WITH THIS PICTURE? ? ? ? ?

I'm sorry, but I just feel that a ham that cannot slobber a PL-259 onto a piece of coass is pretty pathetic! ! ! !

(For those of you who are probably cussing me right now, prove me wrong by buying sone cheap hamfest special PLs and some junk coass and practicing till you learn to do it well)

"Give a man a fish and he wont go hungry tonight, teach a man to fish and he will never go hungry again"

[Todd, KA1KAQ]

Why is it that so many are scared szhtless of putting connectors on coass cables? ? ? ?  

PL-259s are scarey, and N's and BNCs are just terrifying       

Wowsers, where'd you see that?

"I'll have what he's smoking"   

It looks to me more like a 'worth bothering/which is better?' type of discussion. Perhaps less soldering to do on the N connector, but as Mike points out  - more to consider in making sure the center pin does its job properly. With the 259, you just have to make sure you don't let any of the braid strands wander up and mingle with the center conductor. This assumes good soldering skills, of course.

As an aside, I'm still using the silver PL-259s I bought in bulk at the original Hosstraders hamfest at Deerfield, where we now put on NEAR-Fest. Got two big bags of them (10 each, I think) back in the late 80s. Only used a few before going inactive in the early/mid 90s for ten plus years. Since moving south, they've been going much faster. I think the teflon insulator has more to do with handling the heat than anything else, as some of those older phenolic types would deform when soldering if they got too hot. They do work well.

BTW Mike/BTU: heard you calling into Jack/K9ACT's net yesterday afternoon. Couldn't hear you much, but heard someone responding to you. First time on 40m AM? Congrats!

[W0BTU]

... more to consider in making sure the center pin does its job properly.

There's not much surface area on the pin of an N plug. Look how short the contact area is. One of the photos at http://www.w0btu.com/files/misc/N_plugs/ shows that pretty well. I've heard numerous experiences of the coax center conductor shrinking at -20 degrees F and pulling the pin right out of the connector, even with a captivated center pin.

With the 259, you just have to make sure you don't let any of the braid strands wander up and mingle with the center conductor. This assumes good soldering skills, of course.

One thing that's important is not getting ANY solder on the outside of the pin. For long-life, trouble-free connections, we want silver-to-silver, not solder-to-silver.

BTW Mike/BTU: heard you calling into Jack/K9ACT's net yesterday afternoon. Couldn't hear you much, but heard someone responding to you. First time on 40m AM? Congrats!

Thanks! Yes, that was my first time on 40 AM. :-)

I had a problem just before I signed off that I can't explain. The wattmeter after the SB-200 was showing no forward movement on modulation peaks even though the wattmeter on the transmitter was. Kind of scared me.

[KB2WIG]

"Give a man a fish and he wont go hungry tonight, teach a man to fish and he will never go hungry again"
 
 
it should be,

Give a man a fire and he will be warm for a while. Set him on fire, and he'll be warm for the rest of his life.


klc


this post won't last for long, as I'll get it from somebody

[W0BTU]

"Give a man a fish and he wont go hungry tonight, teach a man to fish and he will never go hungry again"
 
it should be, ...

Give a man a fish, and you feed him for a day.
Teach a man to fish, and he'll sit in a boat all day drinking beer.