QRZ.COM
ad: rfparts
ad: L-HROutlet
ad: l-rl
ad: L-rfparts
ad: l-gcopper
ad: Subscribe
ON6MH Belgium flag Belgium

Login is required for additional detail.

Email: Login required to view

XML Subscriber Lookups: 9231

ON6MH since 1974

Working conditions:

Icom IC 7600 transceiver + SPE EXPERT 1K-FA amplifier
Ground plane at 12 meters high for 40M 20M 15M 10M
Ground plane at 10 meters high for 30M 17M 12M
Vertical delta loop for 80M 40M 30M
Inverted L + 2 elevated radial for 160M

Also:

GJ5CCP august 1977 100 w dipole 20 M
GU5EOZ september 1982 100 w mobile 80 - 10 M


GPA-404 Fritzel vertical

 

GPA-303 Fritzel vertical

 

Wellbrook Active loop antenna for rx

 

Vertical delta loop for 80M, apex at 16 meters (SpiderBeam pole 18m)

Inverted L for 160M (SpiderBeam pole 12m rear)

 

Vertical loop corner fed with 4:1 balun, loading coil and coaxial chokes

 

More about the 80M vertical delta loop

First tried this antenna in 2012 using a tall tree in my neighbour's garden.
I had good results and was able to have contact with more then 110 countries.
Unfortunately this tall tree was swept down by a storm in January 2014.

I decided to put up the same set-up using a 18 meters high pole from Spiderbeam.
The size of the back garden being only 6 meters wide and 20 meters long, it was just enough to
raise the pole at 16 meters to support a small wire.
The total length of the loop is only 60 meters, so I needed some loading at the feeding point.

 

The horizontal part of the wire is around 2 meters above the ground.

The loop is fed at one corner using a 25 µH coil and a 4:1 balun.

I made some simulations with Eznec and found the real antenna to be very close to the Eznec prediction.
The vertical radiation pattern is not as good for DX as the theoretical full wave vertical delta loop.
On the other hand, my loop doesn't show directivity as the full wave loop does.

 

The SWR and bandwith are better then the predictions, but it might be from ground losses.

Here is a real world scan with miniVNA:

All in all, it seems to be a good "all around" local and DX antenna.

 

Fighting noise

As in any suburban location, I get a lot of noise on all bands, and mostly on low bands.
Among  many sources of noise I can identify:

- BPL
- Plasma TV
- switching power supplies
- Led lighting and compact fluorescent lamps
- Ethernet networks
- faulty street lights

If it is possible to "silent" your own QTH, there is little to be done for what is coming from your neighbours.
A few months ago, new neighbours moved in and they have not one, but two plasma TV !

One solution I am using to fight noise, is a noise canceller (MFJ 1026).

By using the MFJ 1026, several noise antennas and a tuner, it is possible to reduce significantly those interferences.

My noise level on 80 meters is usually around a real 57, that is 53 on my Icom 7600 with no preamp and 6 db Attenuator.
With my neighbour's plasma TV on, noise is as high as 59 +10 db.

Here below you can see the MFJ 1026 effect at cancelling the plasma TV signal.


Not perfect, but the 80 M band is usable.

 

7933746 Last modified: 2017-02-28 10:08:04, 5102 bytes

Login Required

Login is required for additional detail.

You must be logged in to file a report on this page

Please login now...

QRZ Logbook Summary for - ON6MH

This callsign does not participate in the QRZ Logbook


c
ad: giga-db
Copyright © 2017 by QRZ.COM
Sun Aug 20 11:44:48 2017 UTC
CPU: 0.042 sec 63159 bytes mp