[Johnson] Question on a Valiant.

Sun, 7 Jul 2002 21:48:01 -0400

He's WAY short on output for ANY of those configurations, screen or no
screen current. Still need to know his plate voltage and then possibly
into other issues.

We always used the 75 watt setting for CW. Felt "easier" that way.
Back then the 6146's were a steep little pile of cash for us folks.
Burning out a set meant going back to the 807 rig and saving money for
a while.

73
----- Original Message -----
From: "Glen Zook" <[email protected]>
To: "Guy Olinger, K2AV" <[email protected]>; <[email protected]>;
"Johnson@Mailman. Qth. Net" <[email protected]>
Sent: Sunday, July 07, 2002 8:52 PM
Subject: Re: [Johnson] Question on a Valiant.

> Remember, on the Valiant, as on most "boat anchor"
> transmitters, you are measuring cathode current and
> not plate current.  Cathode current also includes the
> screen current which must be subtracted to get true
> plate current.  Each 6146 draws about 12 mA of screen
> current.  Thus, you have to have 330 mA plus about 36
> mA which is 366 mA at 681 volts for 225 watts input.
>
> Also, remember that the 6146 is rated at a maximum of
> 67.5 watts input for AM operation.  For 3 of them, the
> maximum input should not exceed 202.5 watts, and
> running at this power level will greatly reduce the
> longetivity of the tubes.  They are much happier at no
> more than 60 watts input on AM and no one can tell the
> difference at the other end.  However, the tubes will
> last several times longer.
>
> On CW, the maximum power input is 90 watts, or 270
> watts for 3 tubes.  Again, cutting this back to about
> 75 watts input will greatly increase the tube life.
>
> The power figures are directly from RCA as published
> in various tables in advertisements in QST, etc.
>
> Glen, K9STH
>
>
> --- "Guy Olinger, K2AV" <[email protected]> wrote:
>
> 225 watts input with 330 mils would require 681 volts keydown.
>
> =====
> Glen, K9STH
>
> Web sites
>
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> http://home.attbi.com/~zcomco
>
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