On Saturday, December 29, 2018 at 10:55:23 AM UTC-5, Dan Marotta wrote:
A cheap voltage converter is likely to be very noisy in the RF
spectrum.Â* I tried one for charging a pda and it continually broke
squelch on my radio.

And, as to the original topic of circulating cockpit air, I don't think
that would be of much use and the air in the cockpit is cold. You feel
warm due to infrared heating from the sun.Â* I've felt quite warm in the
sunlight, seen my breath condense in front of me, and been very cold the
instant I flew under a lennie.

Dan

Many of us use such a 12V-5V converter to power a device, such as a PDA, phone, tablet or e-reader, that serves as a glide computer. Some of those off-the-shelf voltage converters are radio-noisier than others. I chose one that had a reputation for reasonable quietness, and added ferrite rings on the wires on both ends of it. It does not cause any practical problems with my radio reception.

Interesting musings infrared heating by the sun. Yeah the perceived cooling when the sunlight is blocked is very fast.