Robert
The problem you describe makes me wonder if your coax and/or traps might be
the issue. Maybe breaking down under transmit power? Or some other
connection might be malfunctioning under transmit power. Maybe the paint
but not sure what to say. Have you reworked every connection to ensure good
conductivity? Are there any antenna switches, barrel connectors, or other
devices used in the transmission line? If so, maybe one of them is
malfunctioning under transmit power.
Any way to remove the coax and test the antenna much more directly by
transmitting from much nearer the antenna using a piece of shorter, known
good coax? Or even ladder line with a tuner?
Does an antenna analyzer indicate the antenna is 'resonant'? Can you
measure field strength and compare it to another known antenna (e.g. perhaps
a nearby dipole).
Is any one band an issue or is the problem present on all bands?
Does the output power drop to a low number (e.g., due to a different SWR
when transmitting then when receiving)?
Keep us posted on what you find as these can be tough.
73 de Jim WA6PXU@ARRL.net
-----Original Message-----
From: towertalk-admin@contesting.com
[mailto:towertalk-admin@contesting.com]On Behalf Of Ffive VHN
Sent: Monday, September 16, 2002 5:46 AM
To: towertalk@contesting.com
Subject: [Towertalk] Cushcraft R5 , Problem ???
Hello,
I was about to permanently install my Cushcraft R5,
but I thought I would test it out first.
I bought my R5 second hand and it has been spray
painted black (With car spray paint I think)
I have installed it on a 7m ally pole, the SWR's on
all the bands are good or OK.
I was using 100W and about 40m (120ft) of RG58 and
PL259's (the coax is made of two lengths and has a
barrel connector in the middle).
The SWRs are fine.
I thought I would take advantage of the contest
weekend to test out the antenna.
However 'nobody' can hear me.
On receive I have no problems, everything seems ok
there.
But it was only the guys I was receiving 20dB over S9
that were able to pull me out.
I received lots of hams using 100w or less (18 MHz)
both local (Europe) and DX but they could not hear me.
So where is the power going.
Is it possible its being absorbed /dissipated in the
ferrite matching section ?
Has the paint got anything to do with it ?
Does the 6m ally pole have something to do with it ?
What is the efficiency of this antenna, it has 4 traps
?
Robert
F5VHN@yahoo.com
__________________________________________________
Do You Yahoo!?
Everything you'll ever need on one web page
from News and Sport to Email and Music Charts
http://uk.my.yahoo.com
_______________________________________________
Self Supporting Towers, Wireless Weather Stations, see web site:
http://www.mscomputer.com
Call 888-333-9041 to place your order, mention you saw this ad and take an
additional 5 percent off
any weather station price.
_______________________________________________
Towertalk mailing list
Towertalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|