[R-390] The Penultimate R-390* Ballast Replacement

[Bob Camp]

Hi

You missed the point, these radios were used by the Navy. All this 
stuff does not sound battleship compatible.

You pick the current off with a reasonable sized magnetic amplifier and 
then feed it into an amplidyne. The amplidyne feeds the field winding 
on a reasonable motor generator set (say 30 HP, they are a common item 
...). The output of the motor generator drives a DC motor that runs an 
alternator. The alternator drives a variac. The variac feeds an 
isolation transformer that plugs in to drive the ballast tube string.  
The whole thing is manually corrected twice an hour by a ballast man's 
mate third class. The correction is done via a pneumatic link to a 
control panel three decks away.

It's really the only way to do it if you think about it.

	Enjoy!

		Bob Camp
		KB8TQ


On Feb 12, 2005, at 6:35 PM, Tom Norris wrote:

> Simplified Block diagram of the Amazingly Complex Ballast
> Replacement Unit (ACBRU) --
> http://www.fernblatt.net/R390/superballast.jpg
>
> Could build a simple comparator circuit driving a
> stepper motor controller that in turn is coupled
> to a motor driven multi-turn pot, but that wouldn't be
> much of a challenge.
>
> Better results could be had using a tube based servo
> amp with chopper amp a`la T-195 autotune circuit with
> selsyns vs newfangled stepper motors. 400 Hz dynamotor
> optional.
>
> The Rube Goldberg Award to anyone that samples the
> filament current, feeds it to a voltage to freq circuit,
> which feeds an AFC circuit similar to the CV-157, complete
> with spinning disk to indicate "live" ballast error adjustment.
>
> All of these would require an external chassis, preferably
> rack mounted. Why use a simple resistor when you can do
> something like this??????
>
> ahem
>
> Time for my medication, or a stiff drink, or both.
>
> Tom NU4G
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