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HB9ABX > ANTENN 18.05.08 20:36l 32 Lines 1114 Bytes #999 (0) @ WW
BID : K12WX7HB9EAS
Read: GUEST
Subj: dc-separator for new hf antenna
Path: IZ3LSV<IK2XDE<DB0RES<DB0GOS<DB0ACC<DB0ACH<DB0NDK<LX0PAC<DB0GE<DB0GV<
DB0SIF<HB9EAS
Sent: 080518/1933z @:HB9EAS.CHE.EU [Basel JN37TM] DP6.00 $:K12WX7HB9EAS
From: HB9ABX @ HB9EAS.CHE.EU (Felix)
To: ANTENN @ WW
Dear OMs:
As previously annnounced, enhancement of the Roomcap
Antenna continues.
This week I tested successfully an interesting new feature:
The Remote Frequency Adjustment RFA does no longer require
a separate control line. The control voltage is now sent over the
coax by inserting a rf-dc-separator, one on the transmitter side,
and one on the antenna side.
I developed this idea with the magnetic loop antenna, and adapted
it now to the specific requirements of the Roomcap antenna. -
This week the field test was performed with a 70m long coax line
between transmitter and antenna.
Insertion of the two devices produced no detectable attenuation
of the system, with the advantage that the separate control line
could be eliminated; and very important:
The short distance of the control line to the antenna created an
rf current on the control line, which had to be filtered.
This problem is now eliminated, as this line is no longer existent.
The next update of the construction guide will contain this new
enhancement.
Best 73s
Felix HB9ABX
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