Italian Dual Beacon at ~ 10.140 KHz


A group of Italian Amateurs has set up a Dual Beacon to test the characteristics of several antennae. The frequencies used are 10.140,55 KHz and 10.140,45 KHz.

The beacon at 10140.045 is terminated on a Vertical Whip and is the “reference”, while the one at 10140.055 is, at present, terminated on a CFA Loop. In the future this antenna will be replaced by other antennae such as an Isotron, an EH and a CFA. These antennae will be homemade by the guys of the local ARI Radio Clubs in Modena and Carpi.

The Dual Beacon follows the “QRSS Knights” MEPT (Manned Experimental Propagation Transmitter) philosophy such as: small power and QRSS 3 modulation. They transmit the call sign “IZ4BFA/B + locator” in CW at 12 words per minute followed by  “IZ4BFA/QRSS” using QRSS 3. QRSS is a way to transmit CW signals at very low speed: in particular QRSS 3 means that a dot is 3 seconds long and a dash 9 seconds!

To receive such a low speed CW signals you need a PC with a sound card and a DSP software. Spectran is suggested as it gives also a graphical representation of the strength of the received signals.

Spectran can be freely downloaded here


10.140,55 KHz => CFA Loop

10.140,45 KHz => Vertical Whip 3/4


The Dual Beacon


This Loop CFA  has been patented and the original documents can be found here

Another example of such antenna can be found on GM3KXQ's site.

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