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[Yaesu] FT-1000 overloaded by AM BC station

To: <yaesu@contesting.com>
Subject: [Yaesu] FT-1000 overloaded by AM BC station
From: wa3gin@erols.com (Dave Jordan)
Date: Sun, 28 Mar 1999 10:02:19 -0500

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I would think the fella is getting the RF from the ground side of his
antenna.
A mile at the away at the AM broadcast band isn't very far away. If the
radio
station is in the USA they have to use a fairly extensive radial system,
etc.

There is company called ICE run by a Ham in Maryland that builds
bandpass
filters for contesters. Model 419 covers all the ham bands and mates to
the
FT-1000 for auto switchings. That system would reduce any incoming
signals
outside the band of operation. They are not expensive as I just bought
one
at a local hamfest for $75.

I believe the FT-1000 tuner is used on receiver but that question should
go
to Yaesu for confirmation.

HAVE FUN,
dave

Nick Kennedy wrote:

>  This is a restatement of a problem that a ham was kind enough to post
> for me ... I have a lot of trouble with receiver overload on my
> FT-1000, apparently when I'm using physically large antennas.  The
> antennas are a 195 foot long Marconi (52 foot vertical, 143 foot
> horizontal) and a 180 foot long dipole (c.f. zepp?) feed with twin
> lead. These antennas present "reasonable enough" impedences so that
> the FT1K's ATU can load OK and transmit on several bands, but serious
> receiver noise from overload is a big problem.  The AM station doesn't
> seem THAT powerful or THAT close to me:  It's about 1 KW day and 500 W
> night and is about a mile or so away.  I'm sure it's overload because
> switching in a few steps of attenuation will make it drop out
> completely while desired signals are merely attenuated as
> expected. Questions:  I read some years ago that some transceivers
> don't use their ATUs  on receive.  I wonder if this is the case with
> the FT1K.  Or maybe with early S/Ns? Also since these antennas aren't
> presenting a good 50 ohm impedence at the antenna terminals I assume
> using an outboard high pass filter might be a problem.  (Filters need
> a good match, I'm told.)  Maybe it would be possible to add one
> internally, ahead of the receiver section.  It would degrade receiver
> performance below 160 meters but might be worth it.  Anyone tried
> anything like this?  Any other insights or ideas for me? 73, Nick,
> WA5BDUnkennedy@cswnet.com



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I would think the fella is getting the RF from the ground side of his antenna.
<BR>A mile at the away at the AM broadcast band isn't very far away. If
the radio
<BR>station is in the USA they have to use a fairly extensive radial system,
etc.

<P>There is company called ICE run by a Ham in Maryland that builds bandpass
<BR>filters for contesters. Model 419 covers all the ham bands and mates
to the
<BR>FT-1000 for auto switchings. That system would reduce any incoming
signals
<BR>outside the band of operation. They are not expensive as I just bought
one
<BR>at a local hamfest for $75.

<P>I believe the FT-1000 tuner is used on receiver but that question should
go
<BR>to Yaesu for confirmation.

<P>HAVE FUN,
<BR>dave

<P>Nick Kennedy wrote:
<BLOCKQUOTE TYPE=CITE>&nbsp;<FONT FACE="Times New Roman"><FONT 
COLOR="#000000"><FONT SIZE=-1>This
is a restatement of a problem that a ham was kind enough to post for me
...</FONT></FONT></FONT>&nbsp;<FONT FACE="Times New Roman"><FONT 
COLOR="#000000"><FONT SIZE=-1>I
have a lot of trouble with receiver overload on my FT-1000, apparently
when I'm using physically large antennas.&nbsp; The antennas are a 195
foot long Marconi (52 foot vertical, 143 foot horizontal) and a 180 foot
long dipole (c.f. zepp?) feed with twin lead.</FONT></FONT></FONT>&nbsp;<FONT 
FACE="Times New Roman"><FONT COLOR="#000000"><FONT SIZE=-1>These
antennas present "reasonable enough" impedences so that the FT1K's ATU
can load OK and transmit on several bands, but serious receiver noise from
overload is a big problem.&nbsp; The AM station doesn't seem THAT powerful
or THAT close to me:&nbsp; It's about 1 KW day and 500 W night and is about
a mile or so away.&nbsp; I'm sure it's overload because switching in a
few steps of attenuation will make it drop out completely while desired
signals are merely attenuated as expected.</FONT></FONT></FONT>&nbsp;<FONT 
FACE="Times New Roman"><FONT COLOR="#000000"><FONT SIZE=-1>Questions:&nbsp;
I read some years ago that some transceivers don't use their ATUs&nbsp;
on receive.&nbsp; I wonder if this is the case with the FT1K.&nbsp; Or
maybe with early S/Ns?</FONT></FONT></FONT>&nbsp;<FONT FACE="Times New 
Roman"><FONT COLOR="#000000"><FONT SIZE=-1>Also
since these antennas aren't presenting a good 50 ohm impedence at the antenna
terminals I assume using an outboard high pass filter might be a problem.&nbsp;
(Filters need a good match, I'm told.)&nbsp; Maybe it would be possible
to add one internally, ahead of the receiver section.&nbsp; It would degrade
receiver performance below 160 meters but might be worth it.&nbsp; Anyone
tried anything like this?&nbsp; Any other insights or ideas for 
me?</FONT></FONT></FONT>&nbsp;<FONT FACE="Times New Roman"><FONT 
COLOR="#000000"><FONT SIZE=-1>73,</FONT></FONT></FONT>&nbsp;<FONT FACE="Times 
New Roman"><FONT COLOR="#000000"><FONT SIZE=-1>Nick,
WA5BDU</FONT></FONT></FONT><FONT FACE="Times New Roman"><FONT 
COLOR="#000000"><FONT SIZE=-1><A 
HREF="mailto:nkennedy@cswnet.com";>nkennedy@cswnet.com</A></FONT></FONT></FONT></BLOCKQUOTE>
&nbsp;
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