[Amps] TL-922 Help

[Iezzi Family]

The current meter on my TL-922 was off a bit.  I had to borrow a current 
probe and adjust a resistor value to get it right.  However, the actual idle 
current for my amp is 60 mA in CW position and 120 mA in SSB position.   I 
have the original tubes.

Steve
KT4FY



> Hi gary,
>
> Actually I am now running the amp with HV on new tubes but no drive.I plan 
> on doing this for 24 hours.The previous tubes were cooked in also and 
> lasted 3 years under severs usage (many contests,etc).The previous  tubes 
> never came up to full power during the 3 years where the previous Eimac 
> tubes had no problem.I have heard the ZG tubes require more drive than the 
> Eimacs but my 850 is good for 80 watts only and I don't want to push it 
> any harder.I am hoping I can recover full power by tuning the 
> input,getting the ig up or changing the bias,if needed for the ZG's.I 
> don't want to try any of this without some expert advice,hi.
>
> Interestingly since I posted this request I found the Kenwood benchmarks 
> for ig,lp and power out in the Kenwood service Manual.
> At 80 watts in and 1KW out,the plate current should be 600ma,the grid 
> current should be 190ma and I have never seen this with the ZG's.My max ig 
> is 100-125ma and plate current is 400-450ma based on band of 
> operation.This is with no ALC control connected.
>
> I'm betting that if I can get the ig up to 190-200ma this will fix my 
> problem.My question is how to do this with 80 watts in.