[Yaesu] 1000MP audio/mike feedback - CAT pulse noise (K1TTT)

[Joe Subich, W4TV]

Scott, 

Since the pulsing is in time with the "CAT" light, this 
is probably an open ground or shield in your mic or CAT 
circuit. 

Since it does not occur in PKT, my guess would be an open 
ground in the mic circuit.  I believe the FT-1000D has an 
RF choke between the "mic ground" (pin 7) and chassis - 
either on the mic connector board or the AF board.  

The first thing I would check is the mic ground wire 
(pin 7) in all of your mic cables and adapters.  After 
that, I would check the choke in the microphone preamplifier 
circuit.  Then I would check the shield (ground) connection 
on pin 2 of the CAT cable, pin 2 of the CAT plug to the 
chassis of the FT-1000D, pin 5 of any DB9 (RS-232) cable 
and the shield of any USB cable (if you are using a USB 
to serial adapter) and make sure your computer shows a 
connection between the shell of the USB port and the 
chassis/power supply.   

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: yaesu-bounces at contesting.com 
> [mailto:yaesu-bounces at contesting.com] On Behalf Of Scott Dickson
> Sent: Friday, October 30, 2009 7:56 PM
> To: yaesu at contesting.com
> Cc: K1TTT at ARRL.NET
> Subject: Re: [Yaesu] 1000MP audio/mike feedback - CAT pulse 
> noise (K1TTT)
> 
> 
> Dave et at:
> 
> My reply to your questions is prefaced by ">>>"
> 
> Additional details are below.
> 
> Message: 4
> Date: Thu, 29 Oct 2009 23:00:28 +0000
> From: "K1TTT" <K1TTT at ARRL.NET>
> Subject: Re: [Yaesu] 1000MP audio/mike feedback - CAT pulse noise
> To: <yaesu at contesting.com>
> 
> It sounds like you have something that is shorting the 
> monitor audio back to the mic.
> 
> If I understand all your options, you get it in lsb/usb even 
> with the monitor off?
> 
> >>> Yes, I do.
> 
> How about in AM?
> 
> >>> Yes, I do.
> 
> Or in pkt-lsb??
> 
> >>> No, I do not.
> 
> Does turning the mic gain or compressor down affect it?
> 
> >>> Yes, both the mic gain and the compressor affect it.  The 
> Processor
> switch must be on for the processor gain knob to affect it.
> 
> Does the monitor volume affect it (even if the switch is off)?
> 
> >>> No, it does not.
> 
> 
> 
> Further details:
> 
> Transmitting on 14.155, listening in another receiver via its 
> internal speaker.  Varying RF output from 100 to 10 watts. 
> 
> Monitor off, no mic connected in USB/LSB/AM.  Go to transmit 
> via MOX button or footswitch to AD-1Y.  I can generate the 
> sound by touching with my finger the metal mike input jack on 
> the Heil AD-1Y.
> 
> The sound also occurs with a mic connected, and closing the 
> PTT.  Speaking into the mic is not required.
> 
> In CW mode, either LSB or USB, closing the PTT give power out 
> and tone, just like going key down.  This occurred no matter 
> if the Keyer and or Brk In buttons were turned on.
> 
> 
> I recorded the received over the air audio, and have put the 
> wav file on my website for download and listening to better 
> understand what I'm hearing. The explanatory remarks at the 
> beginning were recorded via PC.  You will know the difference 
> - it is quite obvious.
> 
> http://w5wz.com/main/page_links.html
> Look for 
> Troubleshooting my FT-1000MP. Here is the audio file of the 
> problem, recorded 10/30/2009 w5wz audio file  - 6 MB
> 
> --Scott, W5WZ
> 
> 
> 
> 
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