I have very limited space and i'm looking for an antenna for 80m. for 40-15 I use a Mag Loop (MFJ1788) and a fan dipole for 12/10/6m.

Could I use a pair of 80m whips in a dipole configuration?? I have space on my rotator so could have it horizontal.

Any other suggestions??

Here in Andover club we developed an all band vertical antenna which covers top band to ten meters, swr below 3 on every band.

Of course, as some big mouth know it allls on this forum will tell you, it can't possibly work so the Chinese, Asian, Australian and American stations we have worked often in these Aerials are all fictions. In fact I don't why I keep mine up. Nor my mate who worked Japan the other night.

Seriously, if you're interested I'll email you the details. For a few quid you can have one up in a week.

D

How limited is limited?

I have a wire going over the house (it rests on the roof) end fed with a 9:1 unun, and it tunes with internal tuners from 160-6m.

Works OK on 80, and quite well from 40-10.

I also have a vertical, it's a 24' 11m vertical, with a 5:1 unun at the bottom, but just as easily could be a bit of wire the same length. It works OK, but nowhere as good as the wire.

Very Limited, hence the Mag Loop!.

I used to have a Western HF10 until my knob of a neighbour kicked off. So I have to be careful about the size of my erections. As my shack is in a detached garage, the only wire I can put up is over communal courtyard.

Pete

Can you not go the other way, from the garage, over the top of your house and secured down the front. A thin black wire would be hardly noticeable.
If you put a "removable" fibreglass pole near the garage at the end of the garage away from the house, and end fed it with a 9:1 unun, you would have quite a workable antenna, much better than any vertical or shortened dipole. (the end with the unun can be hung under the overhang of the garage roof)

You would need at least on counterpoise or radial, but that could be along the fence towards the house, or round the garage. It won't need to be very long..


At the front, you probably couldn't get away with securing it to the front fence, but if you attached a piece of 200kg WHITE kite line to the end, and tied that to the curtain rail mountings where they screw on to the wall, it will easily allow the window to shut over it. Arrange the transition between kiteline to black wire just above the gutter, and it won't be seen unless looking for it. Black wire on slate roof, and white cord against white PVC and wall.

Is that big tree at the front an option? Where is your rotator? Can the pole it's on be used as a support for the wire?

The idea with two mobile whips works, but not very well. I tried it on 40, vertical and horizontal. Bandwidth very narrow, and performance poor. A loop like yours if it covers 80 would probably work better.

I had the same problem at my old location, best antenna I ever squeezed in was an Inverted L with a 40m coaxial trap, the trap shortened the electrical length, you could do the same and add more traps to make it even shorter, a multi trap Inverted L that's what I would try for.

Coaxial traps are a bit of a mess on but not that impossible, you can test them quite easily with an SWR meter and not much more read this........

http://www.marcspages.co.uk/tech/2104.htm


Craig G0KVL

I agree with David and as a member of the Andover Radio club say this aerial is awesome and has enabled me to make contacts to vk ja vs6 ve2 vp west coast of states most of Europe .Don't knock it if you've not tried it..Dave G0AYD FISTS 15892 GQRP 3309 ROYAL SIGS 4209.QTHR QRZ.COM

+1 for the Andover vertical

Tunes easily with an ATU (where you need to)

Cheers

Dave
M6XMA

Dear G4YVM, G0AYD and M6XI have built the antenna, and as you say it tunes from 160-6m no problems at all.

Tried it on 40m last night with a QSO to an inter G station with a 579 report (strictly CW this end!!)

Currently positioned behind the garage (about 4' away from the shack) but I am planning on putting it up on one of the scaffold poles I have up, which are 21ft tall. Also going to add an ugly balun to minimise RF in the shack.

80m and 160 seems to be very noisy so may add another connector from the earth side, and connect to a ground rod I have redundant. see if that helps with min amazing the noise. That was last night at around 2100 so have not really used it when 80 comes alive, time will tell.

I may even end up selling the Mag Loop and buying another nice bit of kit for the shack!

Thanks for all your help and advice, especially G0AYD and G4YVM who I have had email and phone conversations with regarding the antenna. I appreciate it greatly and thats what this hobby is all about and with modern technology, an elmer does not have to be the 'Ham' down the road!

73's all and hope to work you soon.

P.S. build photo's of this antenna are now on my website http://www.g0pnm.co.uk under the 'My Antennas' page. Please let me know what you think

Pete

Nice clear pictures and an easy to understand explanation.
I'm assuming an RF choke at the base of the antenna isn't recommended and the ease it tunes is aided by the length of coax back to the shack.
You wouldn't happen to have a small patch lead to compare readings taken at the base of the antenna to those back in the shack?
Either way, any antenna or idea that gets people space restricted on the air is good.

We have taken SWR reading at the base and further afield. The aerial seems unaffected by coax length, height AGL, surrounding terrain etc etc etc. All of which is very good but all of which rather plays into the hands of the "snake oil!!" cryers.

We had one chap come up and quote text book references at us telling us why the aerial was a fake and would never work. Oddly enough the Asian stations I later worked with it hadnt read the same text books, so worked me anyway.

Like I say in the notes, we make no claims at all for this aerial, except that it works. They now operate in many countries and I have no one come back and tell me it didnt work as well as I say.

If you do play with one and make some interesting finding, do please tell us!

Regards

D

Excellent little article on your website Pete. Im really glad it worked for you...thanks for the feedback.

david

Maybe people could give some credit to the original article?

Would be fair after all, even if not asked for.

As I said to Tony on another thread only last week when i first became licensed i worked stations for an entire week using only the coax as unknown to me I was sold a faulty antenna as it's so-239 chassis connector wasn't making contact with the PL259 centre pin.
I don't doubt this antenna works to some degree and i'm not pouring scorn on it, even a less than ideal setup is better than none at all but surely it must be accepted the other half of this antenna can only be the coax feeding it, the coax braid must be the antenna ground and that being the case my fear in a built up area would be causing RFi.
Read my sig, being told it works doesn't cut it with me.....I want to know why it works.

Oddly enough I tried using just the coax by unplugging the aerial. Castle electronics reckon my PA stage will be fixed in a week.

No, youre right. The aerial doesnt really work at all. I dont know why we bother. If I sound a bit fed up of your comments its because I am. Go away, analyse the aerial, rip it apart and find out why it works. Then come back and tell us. In the meantime, perhaps, just accept that some people are working global Dx on QRP power and having a ball. They dont know why, they probably dont care. They saw an article, they built the aerial and now, using the skills of their own hands, they having fun. Is that so bad?

I wont read this thread again...it winds me up.

D