Type N Connectors or PL-259

[a1emt]

Hello to the board,

Did some research on the above connectors for my base antenna feedlines.

My take on the N-connectors was that they are lower loss and more weather resistant than the PL-259's. My plan was to make all my feedlines and connections with N-connectors for 800 Mhz, UHF and VHF.

However, most VHF antennas and equipment seems to come with PL-259 (Including the good stuff- DB and Celwave Antennas).

Am I missing something? Is a PL-259 superior to N at lower frequencies?

Jim M.

[kb4mdz]

No, you're not missing anything; the two main reasons most VHF stuff comes with PL259 connectors is A) they aren't >>as bad<< at VHF as they are at UHF & 800, and B) they're a bloody lot cheaper than N connectors, both to buy & to install.

Chuk
KB4MDZ

Did some research on the above connectors for my base antenna feedlines.

My take on the N-connectors was that they are lower loss and more weather resistant than the PL-259's. My plan was to make all my feedlines and connections with N-connectors for 800 Mhz, UHF and VHF.

However, most VHF antennas and equipment seems to come with PL-259 (Including the good stuff- DB and Celwave Antennas).

Am I missing something? Is a PL-259 superior to N at lower frequencies?

[kcbooboo]

For 800/900 MHz, you really do want/need N connectors. UHFs have too much loss and the impedance isn't constant.

For higher power levels, the UHF connector has a lot more contact area on the center pin, so it should make for lower resistance. I recently installed a 1kw AM broadcast transmitter that used an N connector for the RF output - while it seems to work, the 1/2 inch coax attached to it was not easy to bend and I was not happy with the minimal contact area that an N connector has for the center pin. I was considering replacing it with a UHF connector for just this reason, but the chief engineer was unwilling to modify his brand new transmitter so quickly. For now, its working.

Bob M.

[bernie]

My two bits worth:
Back about 1936 or so, when 30MHZ was considered UHF these connectors worked just fine.

Especially at higher frequencies the impedance (Z) becomes very critical for optimum system performance.

If you test a transmission line with a TDR (Time Domain Reflectometer)
all of the impedance mis matches show up on the screen.
PL259 really stands out.
Some connectors are made to better specs than others..

The "N" as well as the "BNC" have been around since WWll.

In my work the most power that I had to deal with was a 500Watt Glenayre paging base @921MHZ, as well as some 10 and 20 channel 800 Trunking, and have never had a N connector failure due to power.
There is a power limit for the N connector, as well as the cables.

The one down fall of the N connector is the short body connector that does not secure the center pin. The long body which secures the pin does not have this problem.
I have seen these migrate away from the mating female, and fail.
This was on a 10 channel TeleWave 800 combiner. I would blame the construction rather than the connector.

[tvsjr]

And, don't forget... hambones can install a PL259 relatively easily, while Ns are a whole different matter (some flat refuse to learn how to install quality connectors!)

[kcbooboo]

I have seen three different style N male connectors: the ones on the old Phelps Dodge base station duplexer cables that clamp the braid under a rubber O-ring (like a larger BNC connector) with a soldered center contact, the two-piece style that resembles a PL-259 and even accept UG-175 and UG-176 reducers (anyone can put these on), and the crimp-on ones for RG-214 etc.

Quite a lot of prep time needed for all of them, but the two-piece style (the guts and the screw-on outer barrel) has got to be the simplest and least error-prone of the three. Nothing can go wrong, they can be re-used, and the position of the center pin is fixed from the factory.

Bob M.

[batdude]

the shop where wifey works has these really neat two piece N connectors they use on 9913.

basically you screw on the center pin, solder it, and screw on the shell.

pretty easy and they seem to work great.

i'll get the manufacturer/part number tomorrow and post it.



doug