Hey Richard:

Of the 4 that I have purchased, two SRF-59's were well-aligned out of the
gate, so you're running about average. The SRF-39s have virtually always
been properly aligned - sounds like Sony changed their QA procedures at
some point. I think you probably had a bad one for the first one - I had
a bad one that was not only much less sensitive, but also worse in the
nulling department. I allowed it to have a dignified burial in the
landfill.

My take on the SRF-59's prowess in nulling is that it appears to come from
the fact that the ferrite is up and away from the circuit board which
would otherwise distort the RF field and/or reflect signal into the
ferrite. If you have a picture of the Prison SRF-39, you can see that
there ain't much circuitry in the top where the antenna is - nice design
by Sony. Other models (the Sangeans, etc.) have the ferrite a lot closer
to the circuit board, speaker, etc., which degrades the nulls. Larger
portables like the Sony S5W have the ferrite smack in the middle of
everything, and so the nulls aren't as good as on the mightly little SRF.

Your new SRF-59 sounds like a keeper!

73 - Kevin S
Bainbridge Island, WA