GAP resonance shift
 

I have a GAP Voyageur-DX vertical (160, 80, 40, 20M) which has recently shifted
its' resonance points.

160 now resonant at 1990kHz, previously at 1825
80 now resonant at 3980, previously at 3725
40 not resonant in band, previously at 7100
20 now resonant at 13775, previously at 14150

The antenna is physically solid, all wires are OK and properly attached, the
three counterpoise wires are intact and connected. I have changed out the
capacitor buried at the top with no change in symptoms.

Any suggestions?

--
73, de Hans, K0HB
--
Homepage:
http://www.home.earthlink.net/~k0hb
Member:
ARRL http://www.arrl.org
SOC http://www.qsl.net/soc
VWOA http://www.vwoa.org
A-1 Operator Club http://www.arrl.org/awards/a1-op/
TCDXA http://www.tcdxa.org
MWA http://www.w0aa.org
TCFMC http://www.tcfmc.org
FISTS http://www.fists.org
LVDXA http://www.upstel.net/borken/lvdxa.htm
NCI http://www.nocode.org

GAP resonance shift
 

KØHB wrote:
I have a GAP Voyageur-DX vertical (160, 80, 40, 20M) which has recently shifted
its' resonance points.

160 now resonant at 1990kHz, previously at 1825
80 now resonant at 3980, previously at 3725
40 not resonant in band, previously at 7100
20 now resonant at 13775, previously at 14150

The antenna is physically solid, all wires are OK and properly attached, the
three counterpoise wires are intact and connected. I have changed out the
capacitor buried at the top with no change in symptoms.

Any suggestions?
coroition causing Capitance at some joint?

feedline devolped and leak and changing the matching condiction?

You need to go to spelling class and antenna theory class.

Additional capacitance would LOWER the resonant point, not raise it.

Mismatched feedline will change the VSWR but will not change the resonant frequency.

The Man in the Maze
QRL at Baboquivari Peak, AZ

GAP resonance shift
 

Hans, I suspect there has been a change in what the antenna is coupled
with - coax, ground, radials, housewiring, metal siding, etc... I would
look at that before I suspect internal antenna problems, especially if
it happened suddenly...

denny

GAP resonance shift
 

On Wed, 20 Sep 2006 21:53:28 +0000, Iitoi
wrote:


You need to go to spelling class and antenna theory class.

Additional capacitance would LOWER the resonant point, not raise it.

Mismatched feedline will change the VSWR but will not change the
resonant frequency.

The Man in the Maze
QRL at Baboquivari Peak, AZ

Have anything CONSTRUCTIVE to say, ****wad?

GAP resonance shift
 

"KØHB" wrote in message
ink.net...
I have a GAP Voyageur-DX vertical (160, 80, 40, 20M) which has recently shifted
its' resonance points.

160 now resonant at 1990kHz, previously at 1825
80 now resonant at 3980, previously at 3725
40 not resonant in band, previously at 7100
20 now resonant at 13775, previously at 14150

The antenna is physically solid, all wires are OK and properly attached, the
three counterpoise wires are intact and connected. I have changed out the
capacitor buried at the top with no change in symptoms.

Any suggestions?


Turned out that under power the center conductor of the matching network
embedded in the top main section of the antenna migrated through the dilectric
and shorted to the sleeve, thus making the lower and mid matching rods "hot",
and effectively changing the antenna from a vertical loaded dipole to a random
length vertical ground plane.

73, de Hans, K0HB