>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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