Re: [IC-7000] Oscillation


Don Clark
 

You might want to look at your power supply. Especially if it is a switching type.

On 12/28/2015 3:33 PM, James Brock jamesbrock@... [ic7000] wrote:
 
 This is somewhat hard to explain.  But rather frequently now I get an oscillation showing up on my JT65 screen.  You can see it slowly sweep across the screen from right to left.  Strange thing I hold my hand over the case blower it stops and goes the other direction. No doubt somewhat heat related. 

If I have the input on the antenna that has not yet been tuned (remotely) to frequency the oscillation is worse.  Put on the carrier to get the antenna tuner on frequently and the oscillation considerably lower in intensity, sometimes goes off.

When it gets so bad nothing works I recycle it by turning input DC power on and off. 

It is considerably worse when I have the preamplifier off. 

Recapping, to get it to quit or so low I can operate I make sure the antenna is tuned to frequency. I turn on the preamplifier. And when that doesn't work, turn the power switch off and on. 

It has been going like this for several months. I talked to ICOM about it and they said to reset it. That didn't do any good at all.  The tech at ICOM acted as if something like this could not happen.

Anyone out there have a parasitic oscillation running around? 

I am rather inclined to think it is in the RF amplifier stage.

HELP 

W7DAU
James Brock 541-868-5827

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