Double simultaneous?

For who is interested in radio systems.
An important part of the (super regenerative) receiver is the detector of the receiver combined with the right filtering.
The detector, combined with that right filtering does show us the tones of the transmitter, also the combined, two tones is needed, of a double symultaneous transmitter.
The outputsignal of such a combination of tones is shown in photograph three.
Signals are the down elevator and the right rudder signals which are separate shown in photographs one and two.
When the shape of the signal is right both relais of tone filters are activated, in this case, to have right rudder and down elevator.
Of course all combinations of rudder and elevator are needed (4) and possible.

A German system also is to alternate the both tones a few times each second. With such a system more modulation dept is adjustable combined with higher level of sensitivity of the receiver filters, which can result in an expanded range.
A second trick is, electronic cross linking of the tonefilters of each servo. The activated filter (relais) blocks his "partner" filter electronically.

TF