Sangean 803a / Realistic DX440 Shortwave modification for extended coverage

It's unfortunate that one of the few pieces of work / innovation that I've done that is not actually archived on the internet (at least so far as I can tell) is my description of how to modify the Sangean 803a (and presumably it works for clones like the Realistic DX-440) shortwave radio so that it can get an increased range of frequencies.

The Sangean 803a was my first digital shortwave radio. It served me well when I bought it in 1989 or 1990 until the time that it broke. To this day, the radio's keypad and usability surpassed that of all the other radios I've owned.

It is more of a "hack" than a "mod". Basically you can fool the radio's processor by removing the two AA batteries and putting them back in before it has enough time to fully reset. If you hit it at the right time, you can get reception down to 0 khz (though there is too much internal radio noise to get anything below either 10 khz or 20 khz - AND sensitivity is reduced as the frequency falls). You can also get wide FM reception down to 30 mhz or possibly lower (this uses the FM broadcast band filter so it was useful for getting TV audio from channels 2-5 back when they were analog).

The radio will have strange values in its presets, I think when you use the band switch buttons. So you can store these into the radio's 9 memories.

Another quirk is that you can only tune up in frequency.

My radio is long since broken and sold, so I cannot duplicate this. But I'm fairly sure this would work today on both the Sangean 803a and the family of radios that uses the same general setup (Realistic DX-440).

A much more important modification is that anti-chuffing one that involves opening the radio and snipping a wire to reduce the chuffing (audio muting) when you change frequency to make tuning much more enjoyable.