For UHF/VHF, type N or PL-259?

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Hi folks,

I am about to order my first radio, the Yaesu 857d. To keep things simple, I am going to operate initially only on UHF/VHF with the Diamond x50A antenna (http://www.hamradio.com/detail.cfm?pid=H0-000022), until I get a better of understanding of how to build my HF antenna and so on.

Both the HF and dual-band connectors on the 857d accept the standard PL-259 connectors, as does the x50 antenna. But the AARL Antenna book section 22.9 says that these connectors are not the right thing to use for UHF because they "do not present a constant impedance." It suggests instead using type N connectors and, as it turns out, the x50A is available with type N connectors as well.

How much of a big deal is it, really, to use the PL-259 instead of the type N? And why would both the dual-band port on the radio and the antenna come with PL-259 connectors if they are counter-indicated for UHF operation?

If the answer is that I should in fact use the type N connector, I have the following further questions:

1) I want to use the least lossy line possible, RG-213, but the type N connector is designed for RG 8; can I use a type N connector with RG-213?

2) It seems that there is a crimp-on version of the PL-259 (e.g., http://www.eham.net/articles/27017), but I cannot find a crimp-on version of for type N. Am I missing something?

3) To have the desired effect of the type N connector, would I put type N connectors on _both_ ends of the cable (assuming I get the type N version of the antenna), and then use an adapter for the radio?

I am feeling _really_ confused and appreciate any help you can offer. Many thanks!

KD2BGW



Tisha Hayes:
For VHF/UHF I would go with the Type N connector and for low loss cable, Times-Microwave LMR-400. N connectors are available for crimp-on connections to LMR-400 and a bunch of other cables.

If it is "my" radio and did not worry about warranty I would cut off the PL-259 connector on the VHF/UHF cable and crimp on a N -Male connector and then use a N-Female barrel adapter to the LMR-400. You can find crimp on N connectors for just about any cable type and size out there. One crimper tool and a few dies and you would be set for anything.

It would also help differentiate between the two pigtails, the HF connection would be PL-259. The VHF/UHF connector would be Type-N.

Again, these are my personal preferences and I am sure that a few dozen people will vehemently disagree with me. My general opinion is the PL-259 should have been called the P.O.S.-259.

There is a great article comparing the two types of connectors (PL-259) and (Type-N) in this paper;

http://www.qsl.net/vk3jeg/pl259tst.html

Bob Lewis:
If both your antenna and radio have connectors that mate with the PL-259 I'd just stick with that. Using adapters will gain nothing. Changing out the existing connectors on the radio and the antenna is a whole lot of work for very little benefit. The additional loss in two PL-259 connectors vs "N" connectors is almost nil for 2M and very little for 440MHz.

The primary benefit of type "N" connectors for outside use is that they are water resistant - but a little tape and/or coax seal can take care of that for PL259 connectors as well.

Mike Ritz:
I am going to step in between the AAs here and put a qualifier on the answer. If you are interested in weak signal work (EME, long distance UHF, etc.) I would worry about the additional small loss of a POS-259 connector (as Tisha so eloquently put it!), and a UHF rated Type N. If you are just using the radio for repeater or local work there are other things (like the antenna and terrain) to worry about,  beyond the coaxial connector. I have seen commercial companies use a 100 MHz rated BNC connector for a GPS receiver at 1.57 GHz, and it worked just fine!

73;

Mike, W7VO

DICK WHETSTONE:
W7VO hit the nail on the head.

For general FM repeater use and occasional SSB and / or CW work on 144 and /or 440 MHz, the factory installed PL259 connectors will work just fine.  In this type of use you will not notice one bit of difference on transmit or receive by replacing the PL259's with type N's.

Now if you get into moon bounce or weak signal work on 144 and / or 440, you need to use type N's.  But then the Yaesu 857 is not the rig you would use for moon bounce or weak signal work.

Dick  AD4U

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