>
>I am almost embarassed to ask this. However, since my ego is inversely
>proportional to my waistline.........I have recently acquired a superb HB
>amp covering 160 to 10. Uses Dahl components in the PS, vac. variables in RF
>deck. built professionally by a EE (now SK, RIP). The tube is a single
>4cx1500.
An A of a B?
>My questions is how the heck do you tune this up?
1. apply max. drive with the anode and screen supplies off.
2. adjust the grid bias V until you have almost zero grid-current. Do
not readjust the bias V to set Zero Signal Anode Current (ZSAC).
3. tune grid roller coil for best swr. (neutralized amplifiers only)
4. apply anode and screen potentials without drive. Set
I have used
>triodes all of my life sans my TS-820/830 which use beam power pentodes in
>the final (2X 6146) but I just tune for max power on these. I have always
>avoided tetrodes mosly due to my ignorance of the tune up procedure.
>
>The amp has metering for screen I and E and also grid I and E as well as
>plate I and E. What is the value I need to watch? I assume that it is not
>safe to tune it like my 3-500zs which is usually just tuning for max power
>out with a string of dits at 60 wpm?
>
>Also, what is the going rate for a good 4cx1500 pull? I figure they are not
>too bad since the military used/uses them and they have been around longer
>than I have been alive.
>
>Lane
>Ku7i
>San Diego
>
>PS I am anxious to see how well my "new" Johnson Ranger will drive this!!!
>
>
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>
>
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FAQ on WWW: http://www.contesting.com/ampsfaq.html
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Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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