[Johnson] Question on a Valiant.

Sun, 7 Jul 2002 21:28:12 -0500

I will take some measurements tomorrow and let you know; I was told that the
shunt resistor is the wrong value (I have 5.1 Ohm's now).
This radio is a factory wired and in very good condition, the only thing I
have dome so far is to replace the silver mica loading caps with new ones
this has not changed the output but now it works on all bands. Everything
else looks good; I will post the voltages tomorrow. Thanks for all the help.

Thanks & 73's Dutch
Please visit my Collins web-site
http://users2.ev1.net/~wb7dyw/
And my new R-390 Page.
http://www.qsl.net/wb7dyw

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Guy Olinger, K2AV
Sent: Sunday, July 07, 2002 8:48 PM
To: Glen Zook; [email protected]; Johnson@Mailman. Qth. Net
Subject: Re: [Johnson] Question on a Valiant.

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
>
> http://home.attbi.com/~k9sth
> http://home.attbi.com/~zcomco
>
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