Tri-County Amateur Radio Association - Using Very Slow-Speed for CD

USING VERY SLOW SPEED CW ON 30 METERS

A fascinating email arrived from Larry Putman, WB3ANQ of Pasadena, Maryland. He described working VK6DI in Western Australia on 30 meters using very slow-speed CW, running only 961 microwatts. That is under 1 milliwatt, over an 11,558 mile path. Larry used an old Hewlett-Packard HP-3336 signal generator as a transmitter feeding a 30 meter half-wave inverted vee dipole. To achieve the low output power and measure it precisely, he used a precision attenuator and measured the signal with an HP-3586C Selective Level Meter.

But Larry didn't depend on the station at the far end to copy by ear. The CW was sent in QRSS mode, which has a very slow rate of as little as one word per minute or less for weak signal work. The CW

was pulled out of the noise by feeding the audio into a computer sound card, and detecting with ARGO software.

You can see info on this mode of communication at,

http://www.ussc.com/~turner/qrss1.html, and Larry's operation is

detailed on his web site at, http://www.wb3anq.com/.

You can see the web page of VK6DI on the receiving end at,

http://www.users.on.net/~davroz/vk6di.

Details on ARGO software are at, http://www.weaksignals.com/, and

see the efforts of a group called the QRSS Knights at,

http://www.cnts.be/knights_qrss/.

Also check out ON7YD's page on extreme narrow band techniques at, http://www.qsl.net/on7yd/136narro.htm.

This mode is also used on longwave VLF operations, and you can see information on this at, http://www.lwca.org /.

If you would like to make a comment or have a tip for our readers, email the author at, k7ra@arrl.net.


	USING VERY SLOW SPEED CW ON 30 METERS A fascinating email arrived from Larry Putman, WB3ANQ of Pasadena, Maryland. He described working VK6DI in Western Australia on 30 meters using very slow-speed CW, running only 961 microwatts. That is under 1 milliwatt, over an 11,558 mile path. Larry used an old Hewlett-Packard HP-3336 signal generator as a transmitter feeding a 30 meter half-wave inverted vee dipole. To achieve the low output power and measure it precisely, he used a precision attenuator and measured the signal with an HP-3586C Selective Level Meter. But Larry didn't depend on the station at the far end to copy by ear. The CW was sent in QRSS mode, which has a very slow rate of as little as one word per minute or less for weak signal work. The CW was pulled out of the noise by feeding the audio into a computer sound card, and detecting with ARGO software. You can see info on this mode of communication at, http://www.ussc.com/~turner/qrss1.html, and Larry's operation is detailed on his web site at, http://www.wb3anq.com/. You can see the web page of VK6DI on the receiving end at, http://www.users.on.net/~davroz/vk6di. Details on ARGO software are at, http://www.weaksignals.com/, and see the efforts of a group called the QRSS Knights at, http://www.cnts.be/knights_qrss/. Also check out ON7YD's page on extreme narrow band techniques at, http://www.qsl.net/on7yd/136narro.htm. This mode is also used on longwave VLF operations, and you can see information on this at, http://www.lwca.org /. If you would like to make a comment or have a tip for our readers, email the author at, k7ra@arrl.net.

USING VERY SLOW-SPEED CW