Probably the best DX site in the world
 DX news

More on


General info on the Beverage

How to
Get a perfect Beverage


How thick, what material?


From radio
to antenna

Ground and terminate
— here's how

Remote control of the Beverage

Love letters about life with
a Beverage
You'll need at least four wavelengths

By Jan E Holm, SM2EKM
Topband Antenna mail list, October 19, 2000

Nobody seems to talk about the wave angle of the beverage main lobe, at least I havenīt seen anything.
Seems to me that anything much shorther then 4 wl doesnīt work. If you check Misek's book you can see that you need about 4 wl for 25-30 deg waveangle and anything higher than that is useless.
In any case I have tried many many beverages and for me they donīt perform untill they reach 1000 ft approx, all this work was done on 80 meters, figure same would apply on 160.

By Tom Rauch, W8JI
Topband Antenna mail list, October 19, 2000

I don't follow that line of thought. Even a 1 WL Beverage has good response along the ground for groundwave, and at low wave angles for skywave.
A 4 WL Beverage is about useless because the phase of the arriving wave randomly and rapidly changes in a few wavelengths of distance.
It is virtually impossible to keep two points separated by more than 1 or 2 wavelengths "in-phase" because of the effects of propagation. This is especially true at sunrise or sunset, when the ionosphere is changing.

I've had 3 WL Beverages, and quickly found in A-B comparison to shorter 1 and 1-1/2 wl Beverages they were generally worse....not better. All my long Beverages are now long gone.
The few times the ionosphere is stable enough to allow antennas spread over a large distance to be effective, I can combine a bunch of smaller antennas into a large array from the operating position.
At least on 160 meters, the number of times a year I can use what amounts to a 4 WL long array numbers in the single digits!

By Tom Rauch, W8JI
Topband Antenna mail list, October 18, 2000

Most important, the antenna with best F/B or lowest overall noise often isn't the antenna with best ability to dig out weak signals. Even a few minutes later, that can all change.
The problem I observe is that phase difference of arriving signals, even in a space of only two or three wavelengths, is so unreliable that there is now way a physically large antenna or array of antennas can be "designed" to be optimum.

The largest practical separation that offers reasonably stable combining of antennas is about 1 to 1-1/2 wavelengths of total spatial area. On stable nights, away from sunrise or sunset, it's possible to make the array larger (I can vary the number of elements phased together) but still it requires adjustment of phase between the various antennas.
Now imagine how likely you are to "hit" a magic combination that works with a system you can't adjust, like a 1500 foot Beverage! Sure, you'll find a time and distance where the antenna works better than a shorter antenna...but you'll also find just as many times when it won't work as well as a shorter (1 to 1-1/2 wl area) antenna!

A very large array won't work as well as predicted because phase of the signal won't be stable over the area of the array. Phase can be as much as 180 degrees out one time and back in phase at other times, and it can change from moment to moment on some nights!
We need to be able to determine a directivity factor, and understand that if the array is physically large (more than 1 or 2 wavelengths) the signal arriving at all parts of the array won't allow us to achieve the performance we estimate.
Front page
DX News
Andes DX
DX Lab
In Print
Web Stories

Web Archive
Mail Archive

Search all HCDX
mail since 1995

 About us
About us
Write to us

HCDX mail list

antennX  Cebik  FM antennas  Werner's links  Antenna Elmer  Coax basics