Need help choosing coax and HF antenna

[photogman]

I just purchased a new Elecraft K3. I need to purchase an antenna and coax now. I don't have the first clue what coax I need other than I want it to be high quality, low loss over considerable distance (approx 100-125 feet). I will be putting it through conduit outside but there still may be a small distance that has to be buried without conduit. Is the best coax for this RG8/U and LMR600? Or is their e a better coax than this?

I live on a tall hill with the nearest house about 75 feet on one side with no other structures for thousands of feet. Live in a rural area. I,have a lot of wind where I live. I have to have open heart surgery very soon so maybe there is a little antenna I can setup outside until the doctor clears me to lift in about 4 months when I can put up a bigger more permanent antenna. Recommendations would be much welcomed. Than you.

 

[ab3a]

First, I presume you're discussing operation on HF. From what you describe, and for ease of setup, I suggest putting up a vertical antenna at ground level. It should be relatively easy to set up. Your coaxial cable should be reasonable. If you're looking for something better, I suggest using RG-213.

If you use a vertical, set up LOTS of radials around it (MW broadcast stations use around 100 radials). The radials should be up to about 1/4 of a wave. Bencher makes the Butternut HF9V vertical. If you can't set up a tower and beam, this is a good general purpose alternative. You might need to purchase an antenna analyzer to get the most out of this antenna.

 

[popnokick]

Here's a 2nd to the RG 213 suggestion. I used to sell a lot of it to local hams for HF work and it got favorable reports, resulting in word getting around and more requests for it from hams who frequented the store. It was one of those things in the "old reliables" category that you could recommend for HF or otherwise. And a vertical should work well in your hilltop location. The radials make a major difference so don't skimp there. They don't need to be buried but will need to be staked at the ends if you can't bury them. And you may want to avoid the physical exertion of burying them. And then they will be of course above ground, fanned out 1/4 wave lengths around the radius with the vertical as the center.

 

[scanmanmi]

Don't skimp

I did a VHF temp setup with a 1/4 wave and RG59 at 20' up until I got my LMR400 & Comet GP9 at 35' up. OMG! I went from a local area to half the state! Some say the antenna and coax are more important than the radio. I am, however, having SWR problems on HF because of my tower and gutter proximity to my dipole.

 

[n5ims]

Search the web for a coax loss calculator and put in some numbers for your desired operation (length, frequency, etc.) and see what is recommended. You'll most likely find that on the HF frequencies, the coax loss for the various types of coax is pretty close (unlike on the VHF and UHF bands, where it will vary quite a bit). Your coax choice on HF won't really affect your signal all that much (the difference between RG-58 and LMR-900 for a 200' run would be huge on the higher frequencies - about 26 dB at 900 MHz, but only a bit at 30 MHz - less than 4 dB).

What will make a difference is using good quality connectors and sealing them well against moisture. Since you'll be installing it underground, make sure your coax is designed for that. Using normal coax that's not designed for direct or indirect burial will fail rather early due to moisture contamination. The conduit will help, but not eliminate the issue. The conduit mostly prevents stones or other hard objects from reaching the coax (an important job!) but may actually keep moisture in contact with it longer.

This article has some good information on burying coax. Coaxial Coax Cable and moisture and burying

 

[gaburbano]

TISS: Take it simple and slow..

First hope you are well following your surgery. Thats more important than anything.

Next, put up a simple g5rv or something similar,(I like the DXCC) with some 213 or if you want to spend some more, get some LMR600. Much lower loss over longer distance.

Next, you say you are on a hill, well then get a vertical an R8 I have one and its a great antenna, pretty big vertical and it has the warc bands. You shouldnt do anything other than put it together, and you need some room. it took me about 5hrs to put it together. But then you need a couple of people to get it up and you shouldnt do it. (just looking out for you)

Now if you want to go crazy, well then get a nice beam. But I wouldnt recommend doing that until you are much better. Im assuming if you are pending heart surgery, exerting yourself isnt in the best interest. And after your surgery it will be at least 6 months before you can lift anything, preferably longer.

A wire is excellent, a DXCC or similar is a great antenna with a decent tuner, (dont know if you got the tuner with the K3) its easy to fine tune. You dont even really need one. Its easy to put up and it will do 80 thru 6M

Good luck

George
N2ZNC

 

[gaburbano]

Oh if you do decide on the R8 or something similar, get the guying kit.. Its a requirement...
George
N2ZNC

 

[warnberg]

Only suggestion I have is don't skimp on the cable.


Coax Cable assemblies |RFID Cables |Custom coax assemblies

 

[dksac2]

I would get a "GAP" Challanger antenna. Easy to build, sets up at ground level and only requires 4 counterpoise's, 25' long each for the 40 meter band only. It's much easier than putting 40+ radials out at the base.
Check the reviews at eHAM on this antenna. There are about 4 pages of very good reports and it is one of the more reasonable priced verticals. I'd then use LMR 400 or 600 depending on the distance. L-Com has LMR -400 by Times for $0.75 a foot up to 100' and less for over 100'

I wish you well in your hospital visit. Once you are able, some horizontal dipoles to go with the vertical would give you a great station. The challanger goes from 2 meters to 80 meters with the only restriction that on 80 meters, the bandwidth is 130 Mhz.

My Best, John

 

[N8DRC]

Only suggestion I have is don't skimp on the cable.[/url]

Yes I second that motion...