Topband: whats your 2:1 SWR bandwidth on an EWE ?

[Terry Conboy]

At 09:44 AM 2007-10-30, Neil Carr G0JHC wrote:
>I have recently put up a couple of simple EWE antennas, one firing East and
>the other West. Spec is 5m up at each side and 10m horizontal section. I
>have settled for a 1000ohm termination, which gives a 30db F/B. I wound a
>bifilar  9:1 transformer and the analyzer shows a 1.1 SWR. All pretty text
>book.
>
>My  question is how wide banded are these rx ants suppose to be? I thought
>I'd check the 2:1 swr points on the analyzer and was surprised it never went
>above 1.5.1 as far up as 50MHz !
>
>Is this correct or have I done something wrong? They do seem to be working
>well.

As you found, the bandwidth is considerable.  As long as you have a 
good transformer, the match will be very broad, since they look a lot 
like a terminated, unbalanced open-wire line.

EWEs should have pretty good patterns up to the frequency where the 
length is about 1/4 wavelength, or 40m in your case.  On 30m and 20m, 
the pattern is mostly broadside to the top wire.  On 15m, 10m, and 
6m, there are broad double lobes with a little more gain in the 
opposite direction compared to the topband pattern.  In a pinch, you 
could use it for transmitting on 10m or 6m, as long as the 
termination can handle about 50% of your TX power, since the gain is 
greater than 3 dBi.

73, Terry N6RY