10m coaxial dipole.

Well, the half wave vertical coaxial dipole is up! A bit disappointing, 1.6:1 at 28.5mhz, but that might be the close proximity to trees. At least it'll give me something to play with. 

Perfectly acceptable SWR Deb, I've used one on 10 meters and found it to have the edge on both my HWEF and the single band dipole. Let us know how you get on.

Best 73 Gary.

GaryWilson wrote:

Perfectly acceptable SWR Deb, I've used one on 10 meters and found it to have the edge on both my HWEF and the single band dipole. Let us know how you get on.

Best 73 Gary.

Thanks, Gary.

After I took that photo, I scanned 10m with the G90. I think conditions must have been good as I heard many stations in Europe and S/America, some quite strong.

After a bit of testing, it seems it's resonant at 29.4 to 29.9 I'll take it down and add an inch or two and see how it goes.

Deb

Just an update.

I took the antenna down this morning and added 5 inches. It's resonant now between 28.300 and 29.800 - T5 is 1.1:1 - 26.500 is 1.8:1 - 30mhz is 1.2:1.

I could add another inch, but happy with it as is for now.

This is a cheap but very capable antenna that is really easy to construct.

Deb

Nicely done Deb. I have a homemade one I have used portable and occasionally at home, literally just strung up any fashion I can, HERE is one example I posted on the forum, the wire on other side of pole is just a guy. I hope you have lots of great contacts on your, I am sure you will, and see you've already got a point out of it for our 10m challenge, well done!

Nice one Deb, bring on the E skip!

Best 73 Gary.

If you are using this mainly for DX then try mounting it horizontally. It will become directional, eg. if mounted E/W it will radiate N/S or sloping it to gain lift. When DXing the propagation constantly flips over distance so a vertical is often less effective. Vertical for local, horizontal for DX IMHO :-) I't good to see home made antennas are still popular.

Purple Witch wrote:

If you are using this mainly for DX then try mounting it horizontally. It will become directional, eg. if mounted E/W it will radiate N/S or sloping it to gain lift. When DXing the propagation constantly flips over distance so a vertical is often less effective. Vertical for local, horizontal for DX IMHO :-) I't good to see home made antennas are still popular.

The only way a horizontal single element dipole will help directional gain is by being horizontal, so in phase with other horizontal antennas, beams etc. So my guess (I haven't modelled it) is maybe 1db or less. Then I'd be stuck with only working DX in two directions unless I physically take the antenna down and turn it.

My half wave coaxial vertical dipole is on a 10m pole, so that wouldn't be so easy even if I wanted to. Being a coaxial dipole, it would be difficuli to route the feeder, and the Brewster effect would still cancel some of the radiation.

If there's some gain to be had, and I doubt it, faffing about swinging a 10m pole up and down just wouldn't be worth it for me.

Deb

I must admit I have mine mounted high up on the side of the house aligned N/S and I use it to head out West for the most part. This is from Portugal. It still gets into much or Europe though. I have another wire mounted at 45 degrees to gain lift over a nearby mountain. I am fortunate that I have space for antennas and rather than rotate I switch between setups. When you are talking DX the phase is less important as by the time your signal reaches the other station it is not likely to be in the same phase as it left, it's 50/50 at best. If you were using a Yagi then the need to align with the other station would be far more important. I'm glad I'm not the only one making my own antennas. Good luck! BTW have you tried mounted your dipole as an inverted V? it saves space and can also work well.

Purple Witch wrote:

I'm glad I'm not the only one making my own antennas. Good luck! BTW have you tried mounted your dipole as an inverted V? it saves space and can also work well.

I have 2 acres of land, so space isn't limited for me. I use a random long wire for all HF bands, but needed the coaxial vertical for the CT 10m DX challenge.

Logged two stations in S/America tonight, so I think the vertical is producing the results I want.

Deb

Well done on the two south American contacts Deb.

Horizontal or Vertical.. all theory aside, what works for one person might not work so well for another. Soo many factors can effect how an antenna works. I made some good DX on an inverted V, but am generally doing better with DX on a vertically polarized antenna. But that is just me.

One benefit of using a vertical like this coaxial dipole is that you're probably running the same polarization as mobile stations, so better chance of a copy if anyone passes through locally. Plus same if you use it to talk with any local CB operators. (Deb, you probably know all that, just posting general words for everyone reading)

I wish you many more contacts. Think there's a couple of contests on today so there might be a bit of activity on the band, fingers crossed.

SangueG wrote:

Well done on the two south American contacts Deb.

Horizontal or Vertical.. all theory aside, what works for one person might not work so well for another. Soo many factors can effect how an antenna works. I made some good DX on an inverted V, but am generally doing better with DX on a vertically polarized antenna. But that is just me.

One benefit of using a vertical like this coaxial dipole is that you're probably running the same polarization as mobile stations, so better chance of a copy if anyone passes through locally. Plus same if you use it to talk with any local CB operators. (Deb, you probably know all that, just posting general words for everyone reading)

I wish you many more contacts. Think there's a couple of contests on today so there might be a bit of activity on the band, fingers crossed.

I wouldn't dream of using my 80w pep rig other than on ham bands  

Deb