This is really going to sound strange, but I had a similar problem with my
'1000D. Drove me nuts. Finally found it. Mine was on the LP filter board.
Here's what I found. The transfer circuit uses a small relay to switch the
receiver on and off the antenna, and a pin diode to switch the transmitter
in and out. Check the pin diode with an ohm meter after lifting one side.
Mine was a dead short. The radio still works. Just makes a mess of the
front end. I couldn't find the exact replacement specified by Yaesu, so I
used a 1N4007 diode. It's been in there for several years. Why it comes
out like you described, I have no idea. You should see the mess it made out
of the AM broadcast band. Let us know what you find.
de Dave
WA0ZZG
----- Original Message -----
From: <yaesu-request@contesting.com>
To: <yaesu@contesting.com>
Sent: Saturday, January 01, 2011 2:00 PM
Subject: Yaesu Digest, Vol 97, Issue 1
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> Today's Topics:
>
> 1. From CO8LY (Eduardo Somoano C)
> 2. FT-1000 mystery signals? (Chris Hannagan)
> 3. Re: FT-1000 mystery signals? (K1TTT)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 1 Jan 2011 00:51:23 -0500
> From: "Eduardo Somoano C" <co8ly@frcscu.ciges.inf.cu>
> Subject: [Yaesu] From CO8LY
> To: <yaesu@contesting.com>, "VHF Lista D." <vhf@w6yx.stanford.edu>,
> <sedxc@contesting.com>, <smirk@mailman.qth.net>,
> <rtty@contesting.com>, <rfi@contesting.com>,
> <psk31-request@aintel.bi.ehu.es>, <psk31@aintel.bi.ehu.es>,
> "<nodxa"@con.ceniai.inf.cu
> Message-ID: <002701cba978$4919fa40$4bd0fea9@eduardo>
> Content-Type: text/plain; charset="Windows-1252"
>
> Dear freinds
>
> Merry Christmas and Happy New Year for you and family.
>
> Eduardo CO8LY and family.
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 1 Jan 2011 18:33:37 +1300
> From: "Chris Hannagan" <zl2dx@xtra.co.nz>
> Subject: [Yaesu] FT-1000 mystery signals?
> To: <yaesu@contesting.com>
> Message-ID: <016601cba975$711c50e0$5354f2a0$@xtra.co.nz>
> Content-Type: text/plain; charset="us-ascii"
>
> Hi All,
>
> My FT-1000 has an unusual problem and I would appreciate some help to
> track
> down the issue.
>
> On the bands there are extra signals being generated in the receiver.
>
> I can hear a "copy" of the original signal every 17.4-17.5 KHz away from
> the
> real signal but decreasing in signal strength each "17 KHz step" away.
>
> On my local 10 metre beacon for example, I can hear these "copies" to well
> above 29 MHz.
>
> As you can imagine it makes 20 metres sound really busy in a contest but
> often the signal I'm hearing is not the fundamental one..
>
> This "feature" switches off by momentarily putting the tuner in line. It's
> not necessary to actually have the tuner operate.
>
> The extra signals re-appear when the rig is momentarily put into TX mode.
>
> Possibly related to this is that when chatting on 75 metres, on returning
> to
> RX there are often strong whistles (carriers or images?) that sweep across
> the received frequency for about 2 seconds or so.
>
>
>
> I would appreciate any assistance with this and would like to hear from
> anyone else who might be seeing the same events.
>
>
>
> Thanks and 73
>
> Chris ZL2DX
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sat, 01 Jan 2011 12:51:08 +0000
> From: "K1TTT" <K1TTT@ARRL.NET>
> Subject: Re: [Yaesu] FT-1000 mystery signals?
> To: <yaesu@contesting.com>
> Message-ID: <14E27F5656B64F57BC2CDE7184F7DABF@k1tttibm>
> Content-Type: text/plain; charset=US-ASCII
>
> Yes, that is odd. I have never heard of one that bad, especially at such
> a
> low repetition rate so this is just a guess. Normally you get images like
> that when there is a very strong signal mixing with the desired one enough
> to cause distortion in the receive chain. Since it goes away when you put
> the tuner in line that would tend to indicate that it is in the first rf
> mixer, the tuner would act as an attenuator if not tuned, or as a
> preselector if it is... does turning on the radio attenuator also get rid
> of
> the products? Do you have a signal generator so you could eliminate
> external sources, just to be sure its not something gone bad in the radio?
>
> When you say it returns after tx, does that mean that when you have the
> tuner in line, then tx, then go back to rx they are there? Does the tuner
> stay in line or drop off or automatically tune itself??
>
> If it is an external mixing source the key of course is to find it. The
> 17khz step is probably related to the device that is generating the
> interfering signal. That frequency could be a monitor, tv, switching
> power
> supply, LED lamp, just about anything new that was installed about the
> time
> the problem started, and probably pretty close to the antenna. Double
> check
> shield connections on coax IN the shack, and all ground connections also
> to
> make sure you aren't picking up noise from a monitor or something else in
> the shack. Otherwise you are on a hunt for a loud signal around that
> 17khz
> range, if you can pick it up on a hand held shortwave receiver that would
> help.
>
> The sweeping carriers on 75m could be related. Its possible your tx on
> that
> band is disrupting the device a bit and shifting its frequency. After you
> stop transmitting it goes back to its normal frequency. However, I have
> seen one like this caused by an oscillating voltage regulator in an
> amplifier. As the temperature in the amplifier changed the regulator
> oscillation frequency changed. Do you hear carriers every 17khz across
> 75m?
> if so they could be used to help track the source.
>
>
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
>> -----Original Message-----
>> From: Chris Hannagan [mailto:zl2dx@xtra.co.nz]
>> Sent: Saturday, January 01, 2011 05:34
>> To: yaesu@contesting.com
>> Subject: [Yaesu] FT-1000 mystery signals?
>>
>> Hi All,
>>
>> My FT-1000 has an unusual problem and I would appreciate some help to
>> track
>> down the issue.
>>
>> On the bands there are extra signals being generated in the receiver.
>>
>> I can hear a "copy" of the original signal every 17.4-17.5 KHz away from
>> the
>> real signal but decreasing in signal strength each "17 KHz step" away.
>>
>> On my local 10 metre beacon for example, I can hear these "copies" to
>> well
>> above 29 MHz.
>>
>> As you can imagine it makes 20 metres sound really busy in a contest but
>> often the signal I'm hearing is not the fundamental one..
>>
>> This "feature" switches off by momentarily putting the tuner in line.
>> It's
>> not necessary to actually have the tuner operate.
>>
>> The extra signals re-appear when the rig is momentarily put into TX mode.
>>
>> Possibly related to this is that when chatting on 75 metres, on returning
>> to
>> RX there are often strong whistles (carriers or images?) that sweep
>> across
>> the received frequency for about 2 seconds or so.
>>
>>
>>
>> I would appreciate any assistance with this and would like to hear from
>> anyone else who might be seeing the same events.
>>
>>
>>
>> Thanks and 73
>>
>> Chris ZL2DX
>>
>> _______________________________________________
>> Yaesu mailing list
>> Yaesu@contesting.com
>> http://lists.contesting.com/mailman/listinfo/yaesu
>
>
>
>
> ------------------------------
>
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>
> End of Yaesu Digest, Vol 97, Issue 1
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