12 vdc switching power supply

[trimmerj]

Seeing some pretty hefty supplies for around $20 or so on ebay and would love to eliminate some of the many wall worts used with my radios. Wondering about rf emisions from the switching supply. Or would I be better off with a linear ?
Thanks

 

[popnokick]

Many.... but not all... switching-type DC power supplies throw off a lot of RFI / EMI hash. One method is to buy one and take your chances. You might get lucky, or you might have to "rinse and repeat" by buying another and trying again. Something that increases the chances that you'll be able to manage the RFI / EMI is if the supply has a "noise reduction control". It's a variable knob that changes the switching frequency slightly and may enable interference you're receiving on a given scanner or other device to be eliminated. And adjusting that control may work fine on some of your devices, or it may work on all of them.
If you're willing to spend more, then a transformer-type "linear" DC supply (e.g. and "old school" Astron) almost never produces RFI / EMI.

 

[trimmerj]

Under $20 for a 30 amp switcher, will take a gamble. Can be used elsewhere if too noisy

 

[Hit_Factor]

.... Or would I be better off with a linear ?
Thanks

Yes

 

[737mech]

I have used the Samlex SEC 1212 switcher for years and no noise or problems. Used for four scanners no radios.

 

[mmckenna]

It does depend on the quality, but switching power supplies are not inherently all bad.
I've got an entire trunked radio system, plus a couple of analog public safety systems all running on quality switching power supplies.

$30 is iffy, but like you said, it can be used elsewhere, and it's not a huge loss if it's junk.

 

[K4EET]

Hi @trimmerj. FWIW, going with a linear power supply greatly reduces your chances of interference caused by poorly designed switching power supplies. Like @mmckenna said, a quality switcher (more $$$s) would be better than a “throwaway” $20 switcher spotted on eBay that may or may not cause interference. I have an Astron linear power supply that stays on 24/7 year-round and has been powering my ham and scanner equipment since 1982 without a single failure. Astron is a reputable company and their switching power supplies, although I do not have any, may be compatible with your equipment with respect to interference. Finally, stating the brand of the switching power supply(ies) that you are considering may enable us to make more specific comments with regards to whether or not they might be noise generators. I hope you can find something that works for you.

 

[vagrant]

I have used two different model Samlex switching power supplies and zero noise.
A Powewerx SS-30DV switching supply gives me noise on 6 meters.
An Astron linear supply has not produced noise.

I had a wallwart pwr supply for a Nokia phone that produced noise on HF, VHF, and UHF. When I can, I use switching or linear power supplies over a wall wart.

 

[rf_patriot200]

I have a Alinco DM330MV and a Alinco DM30T Both are switching supplies and 0 noise from either of them on the HF bands .

 

[Golay]

Before you eliminate a wall wart (or a cigarette lighter plug), make sure that component isn't knocking down the voltage.
What is your radio expecting to see? 13.8 volt DC? Or something else?

 

[kc2asb]

Under $20 for a 30 amp switcher, will take a gamble. Can be used elsewhere if too noisy

I wouldn't want to gamble expensive radio equipment on a $20 power supply. Spend a little more and get an Astron or other quality supply.