[Elecraft] OT: Quiet 12V-to-5V converter

[John Gibson]

Dear Elecraft list members,

The recent thread on noisy switching power supplies leads me to a related question. My son n8fyk, who teaches radio astronomy, has set up a project with his students. They are using a 15m direct-conversion Radio Jove receiver in the field to monitor radio emissions from Jupiter, the sun, and the galaxy. The receiver operates from 12V, which is readily supplied by a portable utility 12V battery pack. Their problem is powering their data recorder, which needs about 5V at 0.7A.

The data recorder is designed to operate from three internal AA alkaline cells, but these give a limited run time. My son would like to be able to leave the receiver and recorder for unattended operation for several days at a time. 

One solution would be to use a 12V-to-5V power converter between the 12V battery and the data recorder. For long battery life, it would be nice to have the efficiency of a switching converter. Such a converter would have to be RF-quiet, so as not to interfere with their weak-signal reception. 

I will be interested to hear what list members recommend.

Thank you and 73,

John, no8v