Only Getting 50% Decode On PDW FLEX 6400

This is using SDR Sharp on a RTL-SDR R820T2 RTL2832U 1PPM TCXO dongle. I've gone through the tutorial at RTL-SDR Tutorial: POCSAG Pager Decoding - rtl-sdr.com but am only getting around 50% decode. Here's the settings I'm using. I've also tried different Windows volume settings and still get only around 50%. Any ideas what I should try? PDW does get some stuff scrolling, but there's lots of errored characters. Most of our local frequencies put out FLEX 6400. All my sample rates are set to 48,000 everywhere, but PDW only does 44,100. Thanks.

As you've probably noticed, FLEX is quite different from POCSAG. FLEX is multiplexed, with 4 datastreams per channel (A, B, C and D). To get all four reliably, in the old discriminator tap plus slicer days, we needed a 4-level slicer.

It seems likely that you can improve FLEX decoding with an SDR if you can find the settings that will produce the same results as a 4-level hardware slicer.

Oh yes, I remember the good ole days. I have a 4-level slicer around somewhere and several COM ports on this Windows 7 machine.