I'm going to be up in the attic and on the roof this summer (more solar panels) and plan to mount a dual-band VHF/UHF antenna while I'm up there. The feedline will probably be 75-100 feet to the room that serves as my shack. I've read this post with some feedline numbers. I also ran some numbers on the Times Microwave loss calculator as well.

RG-8X shows a loss of 8.1 dB at 100 feet on 440 mhz, which sounds terrible.
RG-58 is even worse, at 9.9 dB loss.
RG-213 is 4.4 dB loss. 
When you bump up to LMR, things look a lot better. LMR 400 is only 2.7 dB loss and LMR 600 is 1.7 dB loss.

Most of the repeaters around here are 5-25 miles, but a few are farther. I can spend the money where needed on the cable and would like to do it right the first time. On the other hand, I don't want to blow a lot of money on some crazy low-loss cable if I'm not going to see any practical benefit. Would the RG-213 be sufficient, or would I still see benefit from the LMR?

Also, any reason why I shouldn't choose Type N over PL-259 connectors? I know they cost a bit more. 

Thanks for the thoughts. I got my Technician a couple of years ago and more recently bumped up to General. But aside from some HT stuff, I'm only now getting started into more of the home setup.

My go to every day cable is LMR-400 or 600... It's worth it to go with the bigger and better coax. Past that I would say some form of hardline but that gets pricey. You can find good deals on LMR on ebay if you look around.

N-type connectors all day every day. PL-250/SO-239 are okay for VHF and HF but even then I still prefer N there also. Even more so in an outside application and N connectors are designed to be more water proof.

I have been satisfied with the 100' run of lmr400 that I have.  I think that was worth the price over standard stuff.  There are crimp connectors for it as well that work good.

Keep in mind that 3dB loss is throwing away half of your signal!  At 6dB loss, only 25% of your watts are reaching the antenna.  9dB only 12.5% reaches the antenna.   I'm sure that if I'm wrong, someone else here will pounce but I'm pretty sure I'm right.

I know that when I mount my Diamond X-50A I will be using LMR400 since it won't be a long run and I don;t think LMR600 will be a big improvement.

Wireman also has his CQ1000 that is supposed to be an LMR400 equivalent for about a third the price.  I'm looking at that as well if the loss numbers are close.

This is the buy once/cry once scenario. Put in the LMR and you'll never have to deal with it again.

I literally just finished a new run of LMR in my attic on Sunday. The only real issue with it is it's pretty stiff.
It's measurably better on my radios. CX1318FX would be a close substitute that's more flexible if that's an issue.

N is the preferred connector but I've not noticed any issues with 259's in a practical sense.

There are many choices in cable beyond those which you list, which I would suggest you explore.

LMR400 is a fine cable, that I stridently try to dissuade everyone in amateur radio from using as best I can.

LMR400 has a copper clad aluminum center conductor. It is designed to be unrolled off the spool, installed into place and then never move. Repeated flexing will cause breakage of the center conductor over time. Few amateur radio installations are really suitable for it.

What I would suggest for your installation is a more flexible cable with similar loss characteristics. Davis RF Bury-Flex (outdoor) or Wireman #106 (indoor) are what I would suggest that you take a look at.

N connectors are better than UHF/PL259, particularly at UHF and above. If you're putting in intermediate items like lightning protection or something like that, feel free to use them. Most amateur antennas and radios are equipped with UHF connectors though so its usually a moot point. Use a quality crimp or clamp style connector and it will be fine.

Going to larger size cables beyond the 400 size is overkill and pointless for most amateur applications, despite the hue and cry of the arfcom line loss brigade. Spend your money somewhere productive. If you're building a 440 repeater, or 432 moonbounce station then we'll talk about hardline. The 1dB difference between 400 and 600 is undetectable on VHF/UHF FM, and might barely be detectable on CW/SSB, and that's if you have a full 100 foot cable run. A good vs marginal connector installation can make more difference than that. Taking steps to minimize the cable run will also help.

I use DXE-400max.  Very similar characteristics to LMR400, but it has a stranded copper center core.  It runs from my spare bedroom "shack" to my attic antennas.

It works for me, but it is big and stiff compared to something like RG-8X.

This is all great information. My cable knowledge is quite limited and I appreciate everyone's input. 

I'm good with the buy once/cry once plan. I'd better go hop up into the attic to see what kind of flexibility I need. 

The Davis RF Bury-Flex and Wireman 106 look interesting.

Moonbounce may, uh, be a little ways off. 

That Wireman 106 is a nice product. If you need a flexible 400 size cable there is almost no equal. It uses a much finer stranding for the center conductor so is a lot easier handling and presumably less subject to center conductor migration. The jacket material works better IME than the rubbery jacket on the LMR ultraflex cables. I don't use LMR400UF anymore as the jacket is so floppy that the shield braid tends to break at connectors. I switched to the Wireman 8X size flexible cable also. What I really want is an LMR300 size version of that cable but I'm not holding my breath. Amateur radio would have been better served to have popularized a 300 size cable instead of 240/8x size but instead it's virtually unknown. But I digress.

That Bury-Flex looks like awesome stuff, had I known about it I'd have run it instead of the LMR.

I hadn't noticed the #106 Super-8 cable or researched long enough to notice that the LMR was aluminum center conductor.  I can definitely see where it could crack between the radio and the wall if a person were to move the radio or disconnect/reconnect it often.  Good info!

The other end sees problems more often - running cable to a wire antenna, or around a rotator, or just a loop from tower to house that sways in the wind.

Like mentioned above, a 1-2 db difference is hard to notice in real life applications. Get a Bury-Flex or a similar, low loss coax with stranded center conductor and you'll be fine.
Yes,a "hardline" coax is a better choice but it's expensive and the connectors are very expensive and PITA to install. Get a good, high gain antenna, like a GP-9 and you will hit the repeaters, even more repeaters than you have expected.
Try to keep the coax run as short as practically possible. Antenna gain and especially elevation above ground are very important, actually a lot more important than coax loss, providing you are keeping the coax length under 100 ft.

I also use a Cable TV RG-6, low loss cable for my 220Mhz antenna and my scanner antenna. The cable was given to me for free, when the Cable TV company ran a temporary, 500 ft long line to my house. The braid is aluminum but I used crimp-on BNC connectors that do the job just fine, as long as they are sealed from moisture. I would not use it on my kilowatt HF station but some signal loss and slight impedance mismatch is acceptable for what it's used for.

BTW, don't forget about proper grounding and static / lightning protection. I always recommend Polyphaser, inline, coax protectors. None of the "lightning protectors" are designed to protect from a direct lightning strike but they do protect from a nearby strike and from static electricity. A proper, SINGLE POINT grounding system is a must for every ham station.

This is the best, least expensive "400" coax I've found.  Great customer service and fast, reasonable shipping.

http://www.jefatech.com/category/d100-ll400

Gets 5/5 reviews on eham as well.


Type N connectors are standard in other countries/markets, but the UHF connector is dominant here in the US.  Theoretically, the N connectors are better at everything except power handling but that should be a moot point at legal/practical levels at everything UHF and below if I recall correctly.  

That being said, I would advise against type N for a few reasons:

1.  Unless you change the outputs on your radios, you will almost always have to contend with UHF connectors
2.  UHF connectors are less expensive and readily available
3.  It's hard to get away from UHF connectors on accessories, such as watt meters, antenna tuners, amplifiers, lightning arrestors, and many commercial antennas.  For instance, if you want an antenna analyzer you will either pay out the ass for a type N equipped model, or you will have to introduce adapters into the mix
4.  99% of the gear you find on QTH, QRZ or Eham will be equipped with UHF connectors

Long story short, you can use 'em if you want, but it's a battle.

18 feet tall! That thing is a monster. Regrettably, I don't know if I can talk my wife into something quite that impressive coming off the top of my roof. I'm looking at chimney mount options. 

ETA: Have I mentioned that I love ARFCom's technical boards? It would be hard to find a more helpful bunch of folks. I hope to be able to return some of the info some day. (Now if you want to talk medical stuff, that's something I can contribute ;-)

I really recommend the shorter versions that are 8~10 feet tall, versus the monster 18 foot versions. The taller ones have a lot of pattern skewing which is especially noticeable on 440.

I've had a lot of VHF/UHF antennas but this one (GP-9) works better than expected. It is long but it's not too heavy. You don't need to get this particular model. Any dual band antenna will work fine as long as it's relatively efficient and has some gain. I would advise against J-poles unless you want to build one yourself for very little $. A simple 1/4 Lambda vertical with 3 resonant radials will work just fine, unless you want to be able to work distant, simplex stations.

Medical stuff? Don't get me started. Tell me why all doctors are a part of the medical mafia, who's #1 goal is to charge their patients astronomical amounts of money, yet they have no responsibilities to help their patients? They call their practice - a business, meaning that they are not financially interested to fully heal their patients. They want customers to stay sick and return for more treatments, so they can charge more money. There is no competition anymore. They are allowed to create business monopolies, unlike regular non-medical businesses. They are also in cahoots with pharmaceutical companies who's CEOs sleep and dream about putting ALL citizens on maintenance drugs for the rest of their lives. Am I missing something?