Hello Eike,

Just curious. You used the DAIWA to measure the 25W into the dummy load
also?

Something is not right. The measured 14 watts could indicate a mismatch,
but that would surely show up as an SWR greater than 1:1.

Have you tested the DAIWA SWR function independently? Perhaps you have
two problems, rather than one? Is the DAIWA SWR meter calibrated for VHF?

Good luck!

Chuck


Eike Lantzsch, ZP6CGE wrote:
I have a problem with a Centennial Style 5102 antenna.
The antenna simply "does not get out".
The boat owner mounted the antenna to a short stainless steel mast
on top of his houseboat. The boat has a metal roof.
The output of his Icom M402 is 25W into a dumy load. The output to
the antenna is 14W measured with a DAIWA SWR-meter. There seems not
to be any reflected power (SWR 1:1). Where does the 25-14W=11W go?
A simple Lambda-quarter antenna easily makes contact over 40-50km
but this Shakespeare antenna does not even reach 3km.

Can this 6dB antenna have somthing internally broken - interrupted?
Transport damage?

If the connector would be bad I would see this immediately on the SWR.

Is the mounting wrong? Shakespeare states that the antenna does not
need a ground plane - this is my understanding of vertical half-wave
dipoles too - but can the mounting be too close to the metal roof?
Well, the 5102 seems to be a full wave antenna with phasing link.
But anyway my understanding is that this antenna has a voltage maximum
close to the metal roof at its base. This does not seem good to me.

I assume that Shakespeare antennas are well know, widely used
antennas with good reputation. But there are not very many down here
in South Amercia.

Any hint appreciated.
Kind regards, Eike