The AM Forum

Last night I heard the K2ORS becon on 138. He uses his lowfer call there.

Frank,

   Tnx for listening. Running a solid state converted Racal-Decca PA approx 1kW out of the transmitter.
On cw I received a 579 report from Jack VE1ZZ in Halifax,NS also received a report from Mike WE0H near Minneapolis, MN. 

   Using slow speed cw (received with the aid of a computer) I am received every night all over europe, England, Germany, Hungary, France, Portugal, Spain, Russia, and the Netherlands. Since going to the higher power PA I usually receive reports of being the strongest North American station in europe. Some days I'm picked up in europe even before sunset (as early as 3:00PM this past Sunday).

   Longwave is an esoteric hobby comparable to moonbounce, you won't hear much listening for moonbounce with a 2M HT and a rubber duck. Likewise with longwave, it requires specialized receiving antennas and high performance receivers as well as a computer.  Often times a ham a will try to use a ricebox and 80m dipole to listen on longwave and not hear anything. Most riceboxes will tune down there but are as deaf as a post.  But it's fun and addictive. All the guys make their own gear, there is no commericial gear or even test equipment such as swr bridges. There are no jammers or lids down there either!

73 Warren K2ORS/WD2XGJ
http://www.w4dex.com/wd2xgj.htm

Warren,
After the GH net I tuned down there and I could hear an S-5 carrier on 139.2 +/-. In south central CT. I have tuned around in those freqs before but never heard this one

Never having played with slow speed CW could it have been you?

I suspected otherwise since it seemed very steady, yet I could not find a source in the house.

I heard Warren on a coax fed 75 meter dipole. He was weak but well above the noise and easy to copy V V V and his call. There was actually another station under him. The Hot Rod Racal and a Cubic R2307 (Mil R3030) were used. Both work quite well down to about 50 KHz. The Racal hears signals down to under 20 KHz.
Yes, this is very cool stuff and might want to use my Racal with the 50 Hz. filter.
I could see a hot rod lowfer with custom first IF filters.

Hi Carl,
      It was a poor choice of frequencies on my part. I believe the carrier you heard was from DFC -39 a station in Germany used for controlling power utilities on 138.825 - less than 100Hz from where I was operating cw last night.
      I will try again next week and pick a different frequency, away from the transatlantic windows and away from utility staions.

     For slow speed cw software (free download) go to
www.weaksignals.com
and download either "ARGO" or "SPECTRAN"
For info on how extreme narrowbandwidth modes work in general I recommend Rik Strobe's page:
http://www.qsl.net/on7yd/136narro.htm

A proper receiving antenna (or at least matching the antenna you have) and probably a pre-amp are essential as well.  A tuned loop or an active antennas are good ways to go.

73 Warren K2ORS/WD2XGJ

Warren,
Do you have any images you can share here or a weblink.  I'd like to see your setup.  Thanks.
Bob

Bob,
       Attaching a picture of the Decca transmitter, also a picture showing a capture of my signal in Wolfsburg, Germany (my i.d. XGJ in morse code -..- --. .--- ).
 For some pictures of my old setup (250 watt homebrew TX and antenna tuner) see my website (which is in bad need of updating)
http://www.w4dex.com/wd2xgj.htm

73 Warren K2ORS/WD2XGJ

Warren,
I can see why you think it is so cool. It took a while to hit me but as I think back on your signal it sounded like tone modulated spark with all the background noise.
It felt like I was back about 100 years with a better RX.

Frank,
    It's back to the future! Or back to the roots of radio. 

LF operation combines the old and the new, today we use power MOSFETs to generate the transmit signals and digital signal processing to display signals that are below what you can hear in the speaker. 

What makes LF interesting is that the propagation paths are very stable and we can exploit very narrowbandwidth  techniques and integrate signals over long time periods to recover a signal using computers and the power of dsp processesors in sound cards. Often times a signal that makes a very strong display on a waterfall plot is many dB below what you can hear.
The upshot is even though ham sized antennas are very small in terms of wavelength and maybe only 0.1% efficient,  it is possible to communicate across the globe.

73 Warren K2ORS/WD2XGJ

YUP, I need to find the missing modules for my Cubic R3090 VLF RX

Thanks Warren

How long will your trailing wire counterpoise have to be when you take XGJ mobile, Warren?   

Chris,
      It's been done already (by G3YXM), check out the 23 mH loading coil!
http://www.wireless.org.uk/moblf.htm

73 Warren
K2ORS/WD2XGJ