"Steve Nosko" wrote in message
...
#1 reason is the Antenna. #2 cost is king!

Car = antenna on AM & FM

Home radio = Bar antenna on AM and ? what on FM... Sometimes it is the
power cord. Sometimes you have a wire to drape over the lamp shade. The
aluminum backing on house insulation can provide some attenuation effect,
but I'm sure this is less of a factor...it is the primarily the antenna.

Car radios on FM do not have exceptional selectivity as speculated above.
The adjacent channel selectivity is only fair and the systems are made to
only use alternate channels in any one market, anyway. When you're
between
markets and have a weak station 200 KHz away from a strong one that you
have
trouble. If "they" wanted better performance @ home is could be done,
just
costs $$. Low IF for reduced BW can be done in any radio, but size and Q
and frequency are not independent, so lower freq IF means bigger coils and
more "R", so "same Q - lower IF" is not that simple.


Selectivity is easier for FM since they can use inexpensive ceramic filters
instead of IF transformers. Unfortunately, instead of going a few pennies
more for DECENT filters, they use the cheapest they can get away with.

Peter

Pete