Another power supply! (DSP-45 switcher)

My Civil Air Patrol wing upgraded my home radio station, replacing my Motorola Micom 2 with a Micom 3F. The new radio has a nicer display, does ALE, etc. They were also kind enough to send me home with a new power supply, since they'd really like me to keep my radio on full-time so I can be paged over HF. The new unit is a 45-amp switching supply.

It's normally fixed-voltage, but has a jack that you can insert a shorting plug to cause it to bump up the voltage roughly .5V to quick-charge. Better yet, there is a module you can get that turns it into a 4-stage battery charge maintainer. I looked online. and saw them for $65+ plus shipping. However, I also made another discovery: the DPS series of power supplies (and the IQ-4 controller) is actually made for DuraComm by Iota Engineering, and is identical to their DLS series (which seems to be marketed more to RV'ers -- which also tend to get ripped off, but not nearly as badly as telecomm pros do...) -- I call it a power supply; my father-in-law would call it a "converter"). I was able to find an

Iota brand module for $17 shipped. I also dropped the float voltage on the supply (it has a trimpot that's covered by a sticker) from 13.8V to 13.4V since I'm using a conventional flooded battery and not gel or AGM. The weekly anti-sulfation cycle doesn't go as high as I might prefer, but it's close enough.

I do like that supply! Solid regulation (very low ripple, dip of only .1V @ 30A draw), low RFI, efficient & cool/quiet -- I beat it up pretty good last week doing net control, and the PWM fan never even needed to kick in. Plus, it has built-in current backflow protection, eliminating the need for an external diode! I installed in in the cavity where the big PS-36KX assembly was sitting, and freed up a whole lot of space, plus have a cooler quieter supply for the 12V radio stack.

The price on these is actually quite reasonable, too -- cheaper than a [decent] equivalent supply marketed to hams, and has built-in battery maintenance. Good enough!