SB-102 output

[Glen Zook]

If you are getting more than 100 watts output you are
overloading the final amplifier tubes considerably!
The MAXIMUM input ratings for a pair of 6146 tubes is
180 watts on CW, 170 watts on SSB (PEP) and 135 watts
on AM.  That is input, not output!  This is per RCA
specifications.

On 80 and 40 meters, with a new set of 6146 tubes and
running 180 watts input, you should get from 100 to
110 watts output on CW maximum.  On 20 through 10 the
power will drop off.  Now, if you reduce the power
INPUT to about 150 watts which will give about 90
watts output on CW on 80 meters, the guy on the other
end won't know the difference.  However, the tubes
will last a considerably longer time (like 4 to 5
times minimum over running 180 watts input).

If you are truly getting 150 to 180 watts OUTPUT, then
I suspect that the tubes are definitely "running away"
and are putting out all sorts of spurious signals.  If
you happened to put in either 6146B/8298A or 6146W
tubes in place of the 6146/6146A/8298 tubes that the
unit was designed for, it is often impossible to
neutralize the final amplifier and it will definitely
"take off"!

You might want to take a look at the article in
Electric Radio about 18 months ago about the 6146
family of tubes.  You can get the text and the
illustrations from either of the websites that are at
the end of this message.

Glen, K9STH


--- Leisman <wb8baf at VOYAGER.NET> wrote:

I get full output on 20, slightly lesson 15 and 10.
But i get significantly less output on 80 and 40.  On
80 and 40 I am getting only 40 - 50 watts while on the
other bands I easily get 150 - 180 watts.

=====
Glen, K9STH

Web sites

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

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