Re: LF: Antennas

["Douglas D. Williams" <kb4oer@gmail.com>]

Well, no arguing that if you have the acreage, and a nice quiet location, large wire antenna systems are the way to go. Mike Mideke here in the U.S. used to live on a large ranch and, IIRC, had literally miles of wire strung up for receiving, with impressive results.

 

At one point, I had a 260' long "inverted V" antenna that I used on shortwave, and with a homebrew tuner for LF reception, but this was before the advent of QRSS. If I recall correctly, at my QTH the longwire simply picked up more local QRM.

 

I have, on occasion, successfully used very small e-probe "micro antennas" to audibly receive normal speed CW beacons here in the U.S. "lowfer" band (160-190 kHz), at a distance of several hundred kilometers. This is only impressive when you consider our transmitting restrictions on that band, which is 1 Watt input into an antenna no more than 15 meters long (including feedline). But, those occasions were rare, and only during the best of conditions.

 

I'm afraid that, given my current property limitations and QRM environment, small loops and e-probe type antennas are my best option.

 

-Doug KB4OER

On Mon, Jan 2, 2012 at 11:32 PM, mal hamilton <g3kevmal@talktalk.net> wrote:

Doug

If you want to HEAR the signals with sufficient strength to work normal CW . Large antennas of the kind I mentioned are normal on 160 metres for working long haul DX.

Micro RX antennas are only useful for VISUAL QRSS signal observations or receiving Broadcast high power stations.

Let me know when you HEAR an Amateur radio  EU signal with a micro antenna at your qth.

I can only HEAR signals on LF/MF from the USA with sufficient strength for a CW audio QSO using a my large wire antenna system.

They are visible on micro antennas at QRSS speeds but not AUDIBLE

 

de mal/g3kev

 

----- Original Message -----

From: Douglas D. Williams

To: rsgb_lf_group@blacksheep.org

Sent: Monday, January 02, 2012 9:53 PM

Subject: Re: LF: Antennas

Mal, you lost me on this one. Are you suggesting I (or we.....here in North America) erect large verticals, inv L systems, Rhombics, and V beams in order to receive EU LF signals?

 

 

I thought I was doing pretty well with my micro RX antenna!

 

 

Doug KB4OEr

 

 

On Mon, Jan 2, 2012 at 6:28 PM, mal hamilton <g3kevmal@talktalk.net> wrote:

LF es MF

Reports from across the pond and other DX locations as far as Tenneesee and Kansas using micro probe antennas are great for QRSS speeds but not suitable for audio reception.

Take 160 metres for example where it is normal to work world wide on cw but antennas in use are large verticals, inv L systems, Rhombics and V beams, therefore to have any chance of receiving signals at audio level on LF or MF large antennas of the calibre used on 160 metres are necessary.

As well as TX at this QTH I also use large arrays for RX and often hear signals from NA that would not be audible with small loops, micro probes or ferrite sticks

Recently on 500 I was able to copy a W stn 579 but a DL stn copied only on screen, when I asked what strength the signal was I got no reply!!!!!!!!!!!!! using a micro probe antenna.

If a proper large antenna system is not used on LF es MF then there is virtually NIL chance of an audio report from across the pond for EU stns es vice versa

Back some years ago I had audio reports from the Boston area but the antennas were proper wire arrays as used on 160 metres

Small hand held antennas are fine for High Power  BC strength signals but not for low power amateur signals to be heard

No commercial LF/MF station would even consider an antenna of the micro variety.

When I was in the business some years ago on LF/MF Rhombics and V-Beams were the norm

de mal/g3kev