emf distance

A long wire antenna of a full wave, has a 0dB gain, as all of the radio Tx and all of the Rx signals are connected to the etha. Thus so, it may be thought that a full wave long wire may have a 2·2dBi gain.

Unfortunately, the radio front end RF bandwidth needs to be smaller than the manufactures designs. Using a LC tuned circuit, as used with transistor radio may years ago, the parallel LC tuned circuit, a front end preselector can be made. The magic number for the front end preselector is around 150KHz of RF bandwidth.

It is best to use a tuned secondary winding circuit, and allow the RF signal to pass through the primary winding circuit, as the tuned secondary circuit would not be loaded by a signal tap on the tuned circuit. Passing the RF signal through the primary winding, a 3dB Rx signal boost will be found, and for every additional LC tuned circuit filter using the tuned secondary winding, and passing the Rx signal through the primary winding.

It seems however, the best way to adhere to the new regulations, is to use a separate Tx and Rx antenna. The Tx antenna would be to the new EMF spec's, but the Rx antenna can be anything.

The separate Rx antenna, may be just enough to regain the talk / chat distancing we are all used too, and regain the new QSL cards.