Fun with shortwave radio - Radioshack DSP and the MFJ-901b

[se7vennld]

There is an audio mod:

Louder DSP with the RS 21-543 Box

The gain of the audio amplifier can be doubled by soldering wire jumpers across R54 and R57. These are clearly labeled 100-ohm chip resistors on the underside of the circuit board. According to the manufacturer's data sheet, the KIA7227CP audio amp chip does not require these components. After the mod, it's much easier to get room-filling volume from a speaker. Sound quality is excellent, and dsp is unaffected.

[mags71]

After watching this video again, I now have one of these DSP units coming all the way from the USA to me here in South Australia, new in box $45 for DSP $35.00 for freight.

[radionut63]

@mags71 wow... $45.00 bucks is cheap, these things still go for about $60.00 used, well worth the cash if you need the filtering, or an external audio amp for a homebrew radio project. such as crystal radios.