Hello. I'm out of my depth here, but I'll try to be coherent in my question..

I had bought a Tecsun PL-390 after seeing several good reviews by radio
amateurs as well as general public. It's awesome, but crash-prone (and if
anyone can guide me to a means of immediately resetting to regain full
control instead of being made to wait 20 munites for power to fade, I'm all
eyes... I like it enough to be willing to risk some effort to modify it,
given some guidance).

I rapidly became aware of the IC inside it when looking for info about its
bad habits, and having already got an AOR AR-3000 recently set up for RS-232
control decided that this might be a way to go with those IC's, because they
can take commands to do many things already, but by means I'm probably not
familiar with.

I Googled "Si4734 OR Si4735 OR Si4735D60 OR Si4770A20 ttl serial" (minus
quotes) and the results are not promising, I already know that there are many
more experimenters out there with better systems than the commercial
offerings than Google has any clue about, so I decided to ask here. The
Elektor project is one way to go but maybe hard to get, a tad large, and
likely improved on by now, too.

Has anyone come up with a SMALL circuit board, some neat rectangular FR4 PCB
easily mounted to some custom-built conditions, containing the IC, ideally
Si4734 or Si4735 (but I don't need RDS, but do want LW and VHF FM stereo as
well as SW. I am looking for ttl serial at 4800 baud, 8N1 standard setup if
possible, so I can turn an old Psion Organiser II XP into the controller, as
those are cheap, easily found, etc.. So in the same spirit, I'm hoping to
find a small board to use this method to make a radio, so I can ecomonically
make more than one, so I have backup and some future-proofing.

I'd love it if the Tecsun PL-390 worked reliably, I'm all for an easy life if
I can get one, but apparently it is not to be...

Most interesting to me is that the AR-3000 returns signal strength allowing a
programmer to build something like the ETS tuning method of the Tecsun radios
easily! Scan, measure, store if it looks good... A similar method for these
new DSP radio chips complete with TTL on a tiny board is what I'm looking
for.