[ARC5] BC-230 mic

[Ben Hall]

Hi Neil and all,

On 11/9/2014 12:15 AM, AKLDGUY . wrote:
> To run the filaments on 12.6 VDC (with 6AQ5's), I've decided the easiest
> way is to use a discarded laptop or monitor power supply. These supplies
> can even be bought brand new (about $55 here).

The conventional "wisdom" is that these laptop power supplies, being of 
a switching design, create a lot of hash and RF noise.

I use a bunch of Dell part number AD-4214N power supplies that were 
originally supplied with the Dell 1701/2 and 1900FP monitors.  They are 
14 VDC output at 3 amps, so with a dropping resistor (or a diode or two) 
they make nice 12 VDC supplies.  I even use a couple for battery 
charging.  (For use as a battery charger, I believe I've got one or two 
Schottky diodes in-line to keep the voltage at around 13.8 VDC.)

I have not experienced any RF noise from these supplies.

For my SCR-183 setup, I'll probably use a 12 VDC linear supply I've got 
on hand.

thanks much and 73,
ben, kd5byb