As previously annnounced, enhancement of
the Roomcap Antenna continues.
week I tested successfully an interesting new feature:
Remote Frequency Adjustment RFA does no longer require a separate
line. The control voltage is now sent over the coax by inserting
one on the transmitter side, and one on the antenna side.
idea was developed with the magnetic loop antenna, and now adapted to
requirements of the Roomcap antenna.
week the field test was performed with a 70m long coax line between
of the two devices produced no detectable attenuation of the system,
the advantage that the separate control line could be eliminated;
important: The short distance of the control line to the antenna
created an rf
current on the control line, which had to be filtered.
problem is now eliminated, as this line is no longer existent.
next update of the construction guide will contain this new enhancement.
are the pictures:
black box is the 50 ohm rf/dc separator on the transmitter side (1.8 -
The white box is the 50 ohm rf/dc separator on the antenna side (1.8 -