No channels above 47

That works great except I can get the tuner to program any channels above channel47. Is this a limitation of this older model TV
yes there is limitation in old tv.

is there some setting I can change in order to get more channels using the tv tuner?

in INDIA what we do is put a remote control ckt which gives us about 250 channels.
of course we replace tuner also called hyper tuner along with remote ckt or replace whole kit which are cheaply available.& serves the purpose.
hope this will help

Does your Sanyo TV have Aux inputs or just RF coax in? If
1) Coax only = buy RF adapter allows two inputs out to TV
2) A / v inputs available = use tuner source ( cable box,VCR,etc.)
    select video input on TV

Let me know if I helped you or if you need more.....T.