Jury in on 6146B/W

[Steve & Anne Ray]

I have had some replies saying not to use the 6146B in the HW-101/SB-100
series rigs due to a difference in the capacity of the tube.  I have not
had any problems with a pair of 6146Bs in my HW-101, however I did
neutralize the finals by disconnecting the screen and plate voltage and
tuning for min output.  I found that it provided a much better
neutralization then tuning for max output with min plate current.  (I tried
it both ways and there was a significant difference with the plate and
screen voltage disconnected vs. the way in the manual).   I definitely get
more power out approx 120 W on 80/75 meters and approx 80-90 W on 10 M.  I
always crank the drive down to 100 W and let the tubes just loaf.

----------
> From: Stewart Lyon <w6cux at JUNO.COM>
> To:
> Subject: Jury in on 6146B/W
> Date: Friday, January 02, 1998 11:40 AM
>
> Hi Gang,
> I received over 20 responses to my query regarding 6146B's vs 6146W's. In
> my view the most authoritative were from WB9IOG and K4NV. They are
> paraphrased below.
>
> >From WB9IOG via private correspondence --
> "The following is a development sequence
> 6146   Original design
> 6146W  Ruggedized version of the above
> 6146A  Improved basic 6146
> 6146B  Final improvement will generate a bit more power"
>
> >From K4NV in the July Collins reflector and private correspondence --
> To W5DT --
> "...Forget about 6146 and 6146A tubes. Their ratings and design features
> left them both far short in performance when compared to the 6146B.
> The 6146 and 6146A tubes had a plate dissipation of only 25 watts and
> could not stand fluctuations in heater voltage  They were not meant to be
> used in class AB1 service. So, out came the 6146B which had a 35 watt
> plate dissipation rating plus
> it had a new heater design called the "RCA Dark Heater." This heater
> functioned
> better at 350 degrees K below those of heaters in conventional tubes....
> ...The 6146B is a tube specifically designed for SSB service.
> The others were not, only as a compromise."
>
> To W6CUX --
> "The 6146W is a ruggedized version of the 6146...... not the 6146B.
> The course of action to take is the 6146B by GE."
>
> K6KC & W3BJZ said essentially  the same thing.
>
> >From the above, I conclude that the 6146B is a better tube for the SB101
> and should NOT be replaced with a 6146W.
>
> Thanks to all es 73,
> Stu Lyon, W6CUX
> Winnetka, CA
> -ARRL Life Member
>

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