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Reviews Categories | Power Supplies | Steed (formally BaseCom) SM-PS122-2S Help

Reviews Summary for Steed (formally BaseCom) SM-PS122-2S
Reviews: 1 Average rating: 1.0/5 MSRP: $30
Description: Switch mode power supply;
Out: 13.8 volts 2.2Amp continuous (3.5Amp peak, 10% duty
In: 95-240 volts AC
Product is in production.
More info: http://
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G1MMT Rating: 1/5 Nov 10, 2004 04:44 Send this review to a friend
Disaster for HF radios  Time owned: 0 to 3 months
In my opinion, a disaster for HF receivers;

Turning the volume up on my HF QRP rig causes the power supply voltage to oscillate, which in turn causes the front end of the rig to be over loaded by RFI hash and very loud oscillatory sounds (S9 +40) at many points in the 160,80&40 metre bands. Reducing the load by turning the volume down, or turning the LED backlights off on the rig will reduce the oscillation (I'm sure its feedback). On RX the rig is drawing approx 450mA and 1A on full volume (measured).

No problems with drawing the full current (2.2Amps) out of this box, and the output cleans up too!

Looking on the scope I can see a clear low frequency saw tooth-esque effect about 80mV PEP superimposed on the DC level at approx 500-900mA load. This is in addition to the higher frequency 'hash' also present.

It gets hot too.

(Note: The effects described here are not observed when using another power supply; switching, linear or otherwise).

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