Horizontal long wire MW aerial.

[colly0410]

When I lived at my parents house I rigged up a long wire aerial from my bedroom window to a vertical extension tied to the line post, it was pure horizontal (apart from a bit of sag) with no vertical part to it or the lead in, I connected it to my Murphy U130 & it worked great, I didn't use an earth. I know MW signals are vertically polarised & that most long wire aerials are either inverted L's or T's where the vertical part does the grunt work & the horizontal part acts as a capacity hat. I broke the rules by having no vertical part & it still worked great, I know in theory it shouldn't have worked all that well but for some reason it did...  

One day the line post broke (lots of shouting & fuss from Mam) & I tacked it along the fence so my aerial then became a sort of upside down inverted L & it worked just as good as before. BTW I had to pay for a new line post...

[pwdrive]

I've had similar, but the best reception was with part of the wire in the vertical direction.

I'm not sure if polarization of the EM wave can change on it's journey via ground wave...? I know it can via sky wave.

Lawrence.

[Crackle]

I have learnt something new, I always thought a long wire aerial (by definition) was best horizontal to the ground.
I have also just recently learned that a long wire only picks up the electric field of a signal, and this often includes much of the local interference as well. Whereas a loop only receives the magnetic signal and this has less local interference.

If the vertical height you have for a long wire aerial is limited would it help if it was installed in a zigzag up and down, or would each zigzag cancel the other out.

Mike

[Terry]

I also used to use a horizontal long wire but, asI did a lot of my listening in my bedroom, the only way to get a vertical drop would have been by mountaineering up to the chimney to attach a guy rope - no thanks!

Mike raises an interesting point but wouldn't it be a case of the signal picked up by each zig cancelling out the signal in the accompanying zaq?

Going back to my situation, what would be the effect of dangling a vertical drop from the end of the horizontal about a foot out, say, from the wall before the wire passed through the window frame? The bottom end would need to be tied down to prevent it waving about, I imagine, as it would have been if the connection to the receiver was at the bottom in a conventional set-up.

[pwdrive]

RE: Post#3:

It depends on what frequency you want to receive, for MW etc (ground wave propagation) From the transmitter, losses in the E field with horizontal polarization are high due to the earths conduction so vertical polarization is used, the transmitting antenna is typically a classic Tee antenna, the vertical section being the radiating element, this means that the receiving antenna will usually work best if there's a vertical component in it, the classic antenna would be the inverted L.

If receiving DX then it will be via skywave so either polarization can be used for reception because the EM waves polarization will have undergone some twisting in the upper atmosphere and the received field will have taken on an elliptically polarized form.

Lawrence.

[Murphyv310]

How come the Beveridge aerial works the best. My mate has a 1km long straight Beveridge at 4 meters off ground terminated with 330 ohms at the far end. Reception is mind blowing.

[pwdrive]

It's a long antenna and it's unidirectional, he's lucky to have so much room.

Lawrence.

[Murphyv310]

He is lucky.
It runs along a farmers field boundary and he got permission many years ago. It's terminated at his end via a matching transformer to a submersible coax cable which lives at the bottom of the river Ayr. The Beveridge is on the opposite side of the river to his place.
U.S. DX is amazing on medium wave no doubt as the aerial is in an east west direction.

[colly0410]

How come the Beveridge aerial works the best. My mate has a 1km long straight Beveridge at 4 meters off ground terminated with 330 ohms at the far end. Reception is mind blowing.

Think this is a traveling wave type aerial IIRC, it's several wavelengths long so the radio waves sort of push themselves along the wire, it has to be pointing in the general direction of the transmitter. My aerial at my parents house was about 50 feet long..

[Murphyv310]

Definitely a Beveridge aerial.