HF linked dipole - finished

I wonder where the price difference comes from then? Is the Belden name worth that much more? There has to be some difference. The worst outcome is your buy a roll and it turns out to be rubbish and you end up having to buy some better coax and some more crimp on connectors.

Iā€™ve bought ready made cables from them. They are good quality.

Now I roll my own rg-174, having invested in a crimp tool. Itā€™s actually quite straight forward, despite the small size, especially if you buy BNC connectors with a slot in them to aid soldering the centre pin.

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Is that how you roll Fraser? :slight_smile:

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Well I have pushed the button and ordered a roll of RG174 from Farnell. Lets see what its like.
Ta
john

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I have never understood the concern about the weight of a coaxial feedline. We donā€™t make dipoles the way they are portrayed in antenna handbooks, with the ends supported on 20m/85 ft towers and the feedline descending majestically from the centre of the dipole. I donā€™t think Iā€™ve ever had one looking like that. All mine have had a centre support, which also carries the weight of the feedline. Also the feedline is attached to the mast near the connection to the dipole. After that, the weight of 7m of rg58 canā€™t be more than a few hundred grams. The antenna will exert more force than that on the pole in a gusty wind. If the pole collapses it isnā€™t due to the weight of the feedline.
Mostly I now use a ZS6BKW variant ofthe G5RV doublet, fed by 300 ohm ribbon, which is lighter than the dxwire, I think. It flaps in the breeze a bit but is certainly not heavy.

Anyway, we all do things slightly differently and it depends on what method we chooseā€¦

73 Andrew VK1DA/VK2DA

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Speaking of ZS6BWK aka G0GSF did a presentation on this to our club
Useful Information - also a YouTube video as well

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SEVERAL SUGGESTIONS:

  1. regarding the mast, if you deploy the wire as an inverted-L you can eliminate having a ferrite at the top and the weight of the feedline coming down the pole as both can be near the bottom. This will change the resonance of the antenna, adjusting the length will take care of that. It will also shorten the horizontal element making the wire lighter to support. Incidentally, there is no need for an end insulator at QRP levels, and even if one is used, it can be made out of extremely light weight material such as an inch of teflon tube with two holes in it. Beyond the insulator, you can use fishing braid, this is light as thread, non-stretch, and yet can easily be 40 or 50 pound test, STRONG. Now it is all so light weight up there that no back guy will be necessary.

  2. regarding the link for 20/40, you can eliminate that, too, and the need to change it when changing bands. First, adjust the wire length, approximately 67 feet long, for resonance on 40M. Then, hang a short wire stub attached to the middle of the wire and simply hanging down. This stub can be made about 24 inches in length initially, and it will be shortened to something like 18 or 20 inches when you resonate it on 20M. This stub will be ignored on 40M. On 20M, it will be used by the signal which will go first down it, then back up, because it is resonate. The stub is needed because the wire is two half waves in length on 20M, but instead of four ends, there are only two such that the wire needs to be a little longer than it would be for a single halfwave.

If you have more questions, write to me directly using my QRZ email address.

73, Fred KT5X / WS0TA 8X mtn goat

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Try this vertical

https://web.archive.org/web/20090204080405/http://homepage.ntlworld.com/s.amesbury/M3FVB/20m%20port.htm

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Thanks for the info KT5X & cheers M0GIA for the link.

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