[Hallicrafters] tech question please!

[Rich Oliver]

Just say "NO" to switchers.   73, Rich

Nash4447 at cs.com wrote:
> Gotta question for the technical experts ...
> 
> I noticed that the modern "switching" power supplies are able to develop 
> quite a bit of current in a very small package.   I found one of these units that 
> puts out 6 volts regulated at about 15 amps. The reason I bought the thing was 
> that I wanted a supply to run mobile tube radios on my bench. Well, I hooked 
> the supply up to my tube radio and it handled the current load beautifully 
> without even getting hot ( 7 amp load), BUT the damned thing creates so much hash 
> that I can't hear anything through the radio. 
> 
> Does anyone have any good ideas how I might be able to eliminate the hash? I 
> haywired things up just to try it out. The exposed supply was sitting next to 
> the receiver.  Do these supplies have to be in a metal box for shielding ?  
> Would some sort of RF choke arrangement in the output lead help?
> Or are switching type supplies just not suitable for my purpose?
> 
> Glenn K6PZT