[AMPS] Question on TL-922

[measures]

>Thanks for the reply on my first question.
>There is another (very basic) questions:
>
>1. It is said that the tube amplifier need a warming up time. How long 
>should I wait, since there is no indicator for 'ready' sign after the turn 
>on... 

As soon as the step-start relay steps (1/2 second)

>What is the impact if I directly use the amp without waiting?
>
None.  If you have a bad seal, no magical gettering will ever save the 
tube.  

>2. When on standby, the HV is on 3KV. on transmit it goes down to 2.8KV. 
>Is it normal, or should it be steady on 3KV. (I already use Ferro Resonant 
>Stabilizer of 3500 VA)..
>
The drop is due to I x R loss in the transformer.  

>3. With 100 Watts input drive, I only get about 800 Watts output (reading 
>on MFJ-989C tuner). Does it mean the amp is not on top condition?
>
Wattmeters are unreliable.  If the 922 draws more than 700mA, key-down on 
CW, the tubes are ok.  

>4. I noticed that on RFPARTS they only have 3-500ZG (instead of 3-500Z). 
>Can it be used? 

The tubes must have approx. the same mu.  Two types are available.  Mu = 
200 and Mu = 130.  Amperex 3-500Zs have a mu of c/. 200.  They require 0v 
bias at 3000v.  
>
>5. Can we use the RFP 3-500ZG instead of Eimac (the genuine). What is the 
>impact?
>
nothing if you don't mix the Mu.  
>
later, Reinhard 

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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