[TenTec] Omni VI Plus problem, help requested?

[Malcolm McLeman]

Silly question... Same symptoms on dummy load? Malcolm F5VBu

On 2/13/2020 9:30 PM, John Swartz wrote:
> I have an Omni VI Plus that has developed a problem on transmit. Can 
> anyone on this list help me, please?
>
> When I power up the transceiver, in CW mode (I only operate CW), it 
> will generate 80-90 watts output with the PWR control fully clockwise. 
> After several transmissions over a course of barely 10 minutes, power 
> output progressively declines and the ALC light dims and goes out.  If 
> I reduce the power setting to about 3/4 or less, the ALC light will 
> come back, but power output will continue to decline and as it does 
> so, the ALC light will continue to dim and extinguish.  This happens 
> on all bands, but not at the same rate.  On 160, 80, 12 and 10 meters 
> the decline is much more pronounced and rapid, 40, 30, 15 and 17 
> decline a bit less precipitously, and 20 less so.  Even so, after 
> about 15 to 20 minutes of intermittent CW, there is very low output on 
> any band and the ALC indicator does not light at all.
>
> If I start operating at reduced power, I can rely on the output to 
> maintain its level for a greater amount of time, but it does decline 
> after a while, but I couldn't count on it for any extended operating 
> period of more than, perhaps, 30 or 40 minutes.
>
> Can anyone give me any ideas about what is going on, and how it might 
> be fixed?  The receive function is not affected.  I would seriously 
> like to keep this rig working if I can.
>
> Thanks for your time and attention, 73, John WA9AQN
>
>
>