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Hi Collin,
Please take a look at this site
Alan’s site is the encyclopedia of mobile ham radio.
Also, there have been multiple tech nights/club presentations here, so you should be able to find them in the back catalog of club and tech night presentations on this site.
73 de k1jbd
bammiAn alternate is to use a heavy spring on one end, Home depot has several. I used an old door spring at one time. Worked fine, accommodated the tree sway and weight of ice (snow does not stick around to be a consideration) quite well. This assumes your antenna wire/rope are both up to the job.
73 de k1jbd
bammiom KC1NCT
I echo what Hamilton wrote about vertical dipole vs. horizontal, especially the points around DX vs NVIS. My reason for this post is to let you know a easy and cheap way to construct a vertical dipole. (see 2 you tube videos below from where I got inspiration)
- Take a 1/2 wavelength of Coax (I used RG 58), + about 16 ft extra
- From the cut end measure 1/4 wavelength
- Strip that 1/4 Wavelength outer conductor and shield, and just leave the inner conductor with its jacket intact
- Keep the whole coax intact for the next 1/4 wavelength
- At the bottom, wind a ugly balun/common mode choke with the extra length of coax beyond the 1/2 wavelength
- At the end solder a so 239 (female) and seal it with coax seal
- Seal the 1/4 wave point where you stripped the outer jacket and shield so that water does not enter the coax there
- Hang the the whole shebang vertically from a tree with the stripped end on top by the inner conductor
- Feed it at the bottom where you installed the so 239
- For wave length calculation use 3e+8 * VF / Freq in Hz, where VF is the velocity factor of your coax
This has significant advantages over taking a horizontal dipole and hanging it vertically, the chief advantage is that you are feeding it at the bottom. The middle feed for the turned horizontal dipole is problematic because you have to feed it perpendicular to the vertical, which is near impossible to do in midair. The second is cost: about 48 ft of RG58. Most hams have 50 ft of random coax cable lying around! In the worst case you can make with from cheap 75 ohm TV cable, the impendence will not make any noticeable difference at HF.
For the ugly balun, for different frequencies, I have followed the recommendations in the following article for diameter and number of turns. I make a form out of cut Amazon shopping boxes around a cross of junk wood pieces each of diameter length, crudely nailed together. Once you have the balun wound, tape/wire tie it and pull out the form.
http://www.karinya.net/g3txq/chokes/Here are 2 You Tube video of the vertical dipoles by VK2PRC and G5TM
I have deployed 15, 17, 20 M versions at various points and am very happy with the outcomes.
73 de k1jbd
bammiI keep mine connected all the time. Please be aware that the meter is rated – if I remember correctly – at 200 w max in case you are using an amp.
73 de k1jbd
bammiRyan
To help me with such decisions I like to use a Azimuthal Map. My preferred site is https://ns6t.net/azimuth/
I entered your grid square, and the resultant map is attached. You can read off directions labeled around the Map to give you an idea relative to the rest of the world how you will be oriented. Given wire antennas radiate broadsides you can see that the antenna would do well across the US, and Africa, but not so much UK/Europe. IMHO the difference between 180 or 210 is a wash in practical terms, I would choose the further/taller tree, if you can mount a mast at the peak of your house to elevate the balun and run a longer vertical run of the coax into your shack, then definitely use a very good choke at the end of the coax before you run it into your sack to choke off the common mode current that will inevitably be there on an end fed.
Hope that helps,
Hi Craig
i tried to upload my cab file and the site rejects and refuses the upload. Is there a preferred email where I could send the files.
you can see my attempt on the original WFD topic here.
I guess the forum does not allow log files to be attached.
It gave me the following error after I hit submit.
k1jbd.log: Sorry, this file type is not permitted for security reasons.Attached is my modest log for WFD 2021, hopefully in the correct CAB format, with the Club field “NashuaAreaRadioSociety”
73 de k1jbd
bammiI added my support as well, even though I am not from NH, i think it is just as important in an emergency for the traffic to get out to neighboring communities in MA, ME VT etc. for obvious reasons a decent antenna is required.
Derek,
I previously have used va2fsq’s Win4KX with my Elecraft radios, both using a dongle and also using the I/Q output from my KX3 via a soundcard to drive the Win4KX. While this works, it shows you the spectrum, and lets you QSY by clicking on the Spectrum, it is not great.
A much better option is to use your choice of SDR and SDR software like SDRSharpe/SDR Console/SDRUno which have way richer functionality, and then set up two way sync between your radio and the SDR software using CAT control. All of the above SDR applications support this functionality, and it is IMHO a much superior experience, including ability to look at a much wider swatch of the band, or even other bands. You will need a T/R switch if you don’t already have one, or if your Xcvr does not have a separate receive antenna input – for example aMFJ-1708B-SDR . Look for umpteen videos on YouTube that show you how to do this. For example:
https://youtu.be/mGmoWoaek34—
73 de k1jbd
Bammi