Stefan (& All): Yes, I am using a pair of reversible EWE antennas, sized
5.5m tall and 21m long for NE~SW and SE~NW directional reception. The
transformers are 10.5:1 on three BN73-202 cores glued together end to end.
Four ground rods placed in a square pattern, one for each antenna
transformer and one ground rod in the center.
A common mode choke is used in the RG6QS feedline a few feet away from each
antenna transformer. Two feedlines for are used for each antenna and an A/B
switch is used at both the SE and SW transformer locations to switch antenna
A or B. Two feedlines go to the receiver converter and the feed lines are
grounded at midpoint between the antenna location and the receiver location.
At the receiving station, the two feed lines go to a coaxial, opposing
phase, common mode choke. I terminate one output of the opposing phase CM
choke with 75 ohms and other output of the opposing phase CM choke goes to
the LF/MF converter via 75:50 ohm isolation transformer and LPF.
So I can reverse the direction of a single antenna at the station by
changing the position of the 75 ohm termination resistor and isolation
transformer coaxial jumper on the opposing phase CM choke. I can also
reverse the input of either of the two feed lines to the opposing phase
common mode choke, which has a phasing effect for noise reduction which is
somewhat frequency dependent from 10kHz to 500 kHz. I have to walk outdoors
to change the A/B switches to select antenna A or B, but I need the exercise
~:)
https://www.dropbox.com/s/xw0flkh343xhamg/LFMFEWE.JPG?dl=0
https://www.dropbox.com/s/5ygrqqv624c73y7/ewegnd.JPG?dl=0
The antennas are somewhat like a pair of K9AY loop antennas. The EWE
antenna was invented by Floyd Koontz
WA2WVL. This LF/MF version is similar to a reversible EWE antenna Floyd
described in his February 1995 QST article,
"Is This EWE for You."
I also recently installed (8-2015) a low-impedance ground system for my
residence AC power service, which also helped to reduce the local noise
levels from LF through HF....
73 Mike wa3tts
----- Original Message -----
From: "DK7FC" <[email protected]>
To: <[email protected]>
Sent: Tuesday, December 08, 2015 6:25 AM
Subject: Re: LF: Re: Tnx Stefan
Hello Mike,
Thanks for watching and reports. I think you are my best DX to the west so
far. Do you use a directional rx antenna beaming to the east?
73, Stefan
Am 08.12.2015 08:13, schrieb Michael Sapp:
Stefan: Very Nice signals in EN90 this evening/morning....
https://www.dropbox.com/s/nkmcnfjpd8iaad6/IMG_0038.JPG?dl=0
https://www.dropbox.com/s/xupwslfyw8rx4py/IMG_0040.JPG?dl=0
2015-12-08 05:44 DK7FC 0.475682 -22 0 JN49ik 1 WA3TTS/2
EN90xn 6636 298
2015-12-08 05:54 DK7FC 0.475682 -23 0 JN49ik 1 WA3TTS/2
EN90xn 6636 298
2015-12-08 05:34 DK7FC 0.475682 -22 0 JN49ik 1 WA3TTS/2
EN90xn 6636 298
2015-12-08 06:04 DK7FC 0.475682 -23 0 JN49ik 1 WA3TTS/2
EN90xn 6636 298
73, Mike wa3tts
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