You want to keep the copper from oxidizing before the solder flows. Resistance, arching, lack of strength are all things you don't want on a fun outing or in emergency communications. You may have noticed I am using electronic wire clippers. Cutting ladder line insulation out to allow passage over the 4 way PVC center piece. I use an old style hand crank drill for all my holes. I think these three pictures speak louder than words.
You want to drill holes in each ends and both side of those ends that fit the gauge or wire you are using. I as you can see trimmed extra insulation out of one window space in the ladder line. This allows the conductors to go over the center insulator like a pull over vest. This creates a nice support for the feed line and also takes stress off of the solder joints. The zip ties do a nice job of keeping things in place without the use of glue, tape, or cement. As you can see from a close view you can see there will be several ways to hang this antenna from the middle.
Soldering the feed line ends to the dipole elements can be a chore if you are new at it. As I said before clean well fluxed metal is what make the job easy and the end result strong. For those of you new to soldering. I happen to use Oatley's brand but any resin flux should do. To be honest I don't know if it is still made but if you have it don't use it for this type of project!!! Fluxing the joints before heating will insure the metals to be soldered remain, or become clean.
Make sure the area to be soldered is pretty well covered in a light amount of flux. I have posted 2 images here of the joints. The first picture shows the wires wrapped around one another with the flux applied. In the second picture You will notice how the solder flowed and created rounded connections between the metal types. This is called capillary attraction.
When you see this happen you know the solder and the joint was hot enough to make a good solid molecular bond. This will assure that maximum antenna voltage and current can pass through with out being hindered by resistance of some sort. The idea of a good antenna is to get as much RF Radio Frequency energy from the transmitter up the feed line, down the element and radiated into the air.
The last thing we want is a road block or a lane closed : I think you get the idea! When you are done soldering use your clippers to trim the solder joints.
Often there is a wire end or ends that need to be trimmed a bit. Doing this keeps you from getting a cut on your hand or finger. It is a nice bit of house keeping before you wash the joint with your wet sponge. The sponge will take a lot of the flux residue off of the joint. If you want the joint real clean proceed to the sink with a drop or two of dish soap in your fingers and clean it that way, then rinse and dry.
You are almost finished! You will need to solder your coax to the other end of the ladder line. The image on the link above shows the coax directly soldered to the ladder line. You can also buy these from Radio Shack or on ebay at times. If I had had the money and wanted to take the time I would have enclosed this connection in a plastic project box. Again Radio Shack. It would have made it look nicer and been perhaps safer in the long run.
It can be short, long, low loss like RG or RG 58u mobile type coax which is quite lossy for long runs ,yet very flexible. Coax loss at HF frequencies is fairly low dB wise. If I had a location other than my 3rd floor apartment I would permanently install this antenna.
At that point if the feed line run was long I would likely use Low loss Hard Line to keep the loss to a minimum. You now have a visual of how I did my version of the G5RV multi band dipole.
I would enjoy hearing from you if you build or come up with other ideas for this antenna. Questions are also welcome along with comments. As I use this antenna I will try to take some station picture so you can see it up and in action. Thanks for reading this instructable! I heard conflicting opinions some saying it will end up close to 50ohms others stating would be off and require a balun.
Also in response to suggestion of air wound choke- these are only mildly effective at a very narrow freq range. Ferrites either snap on or other of proper mix will provide much higher resistance over a wider freq range. Most commercial all rf chokes use ferrites on coax in an enclosure w connectors for this reason.
I have a full size, pretty much "all band" G5RV installed more or less permanently at home. I think this half size G5 should be great for camping or picnics But if it's not possible with this setup then I would be happy just getting on the air. Thanks Cecil, I found a way to run it North South. I have an old TV antenna mast I could mount the center to; however that would mean I will be running the antenna about 5' above my metal roof.
Should I be expecting any problems from this or is the 5' enough separation. The antenna has a 29' lead section, can that be run along the metal roof? If not how much separation will I need to avoid interference? Lastly what is the best way to support the ends up high?
I've seen fiberglass masts online, but at the moment its not in the budget. I kind of need a diy option. Last edited: May 18, I don't think your dipole is going to like a metal roof under it. You can tweak the lengths slightly to suit your height, operating preferences, etc.
However , removing 8. Even though the VSWR is relatively high on 75 and 80 meters, lower coax loss on that band at least lets us operate there using just one multiband antenna. NOTE: The remaining 8. It must be totally removed from the feedline. Note that the SWR values in the above charts are at the antenna. Some commercial G5RV antenna designs rely on the loss in a long coax feedline to bring their claimed SWR down in lieu of—or in addition to—an antenna tuner.
You should use a ferrite-core broadband current balun choke right at the junction of the window line and coax to keep RF off the outside of the coax shield. A much better alternative to any of these three antenna designs is running the open-wire line from the center of a dipole all the way to a balanced antenna tuner, which was recommended by Louis Varney, G5RV himself. That antenna will work on ANY band from 80 through 10 meters. Each leg is approximately ft.
It is fed with ladder-line all the way from my Ten Tec tuner to the dipole. I also have a built in turner in my Yaesu FT D.
0コメント