[MAMS] 7289 operating voltages

[Dan Michnay]

Dan

Checkout the article written by N6CA in QST( A Quarter Kilowatt amp for 
1296) some years ago and in several issues of the ARRL handbook. Also 
see his website for update info. I have one of his amps and in my 
experience there is a great variability in what Po you can get vs the 
individual tube. Some are much better than others. He recommends using 
only Machlett tubes by the way.

I can usually get about 125 watts at around 300 Ma with roughly 1100 
volts on the plate. Another issue is the accuracy of the power meter you 
are using but you probably have that covered. My stuff is not up and 
operating right now or could get more definitivenumbers.

GL and 73
Dan K9EA
On 12/3/2012 10:47 AM, Danny Pease wrote:
> I am in need of some real world operating parameters for a single 7289 in
> grounded grid on 1296. Plate current and voltage, grid current and voltage
> (both keyed and in standby) and efficiency.
>
> WJ9G has a single tube cavity amp and is only seeing about 90 watts out with
> 8 watts of drive, plate voltage is 1200 VDC at 300 milliamps. I would expect
> to see more than 150 watts given the drive level and input power.
>
> He has set the bias to get 25 milliamps of idle current but has not actually
> measured what the actual bias voltage is when keyed.
>
> Any real world measured numbers would be a great help in trouble shooting
> his output issue.
>
> Thanks
>
> Danny NG9R
>
>
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