On 11/16/2017 1:36 AM, Helmut Wabnig wrote:
On Thu, 9 Nov 2017 15:23:15 -0600, amdx wrote:

I'm installing an active antenna.
https://www.ebay.com/itm/MiniWhip-Ac...72.m2749.l2649

The seller discusses choking the feedline to prevent it
from adding signal.
How do I best accomplish this.
I don't have any beads, I do have loads if ferrite potcores and some
toroids.
The antenna will be up 24ft, last 4 feet is pvc, the first 20 ft is
steel.
Will it help to run the coax inside the mast?
About 75 ft of the coax is run underground and then about 7 feet up to
the radio.
I plan to choke it at both ends.

Mikek


This is no antenna, it is a joke, a bad joke.

w.

Helmut,
I got my long wire up. 16ft high sloping up to 50ft high.
It's 132 ft long plus another 16ft down and 4 more ft into the house.
I tested from 211kHz to 1600kHz because that's what the antenna switch
on my the radio allows.*
My active antenna is better at 211kHz and much less noisy, at 325KkHz
the signal strength is about equal, but still the active antenna has
less noise.
In the lower half of the AM band the long wire is equal or 1 S unit
higher in signal strength.
In the upper half of the AM band it is about 2 S units higher signal
strength.
The long wire is always noisier. The Active antenna is preferable.
In fact the active antenna has less noise on every band where I tested,
5MHz, 10MHz and 15MHz.
I still want to hook up an external antenna switch and test it at night,

but right now, the active antenna is clearly the winner.

I'm not in a particularly noisy area. In the middle of the AM band,
1025kHz (mid afternoon),
I have 1 S unit on the active antenna and 3.5 S units on the Long wire.


* I have an Icom R71a, the radio has two antenna inputs, a UHF connector
input and a long wire input.
The antenna input is manually switchable up to 1600kHz and then radio
takes over and only the UHF antenna connector is used.
Hmm, for some reason my unit switches at 1598Khz.

Mikek