"Tony Meloche" wrote in message
...




In many, many applications today where an AM tuner is included (a
low-priced stereo reciever is a good example) the AM circuitry is not
even as good as the better "pocket" transistor radios of the 1960's.
The designer's view is: "Hey, they aren't buying a stereo rceiver to
listen to AM, fercryinoutloud!" - and they save some nickles there. The
difference between a workable AM circuit and a really *good* AM circuit
is the width of the Grand Canyon.

Huh. That's got me wondering if one or more of the suppliers has come up
with a cheap, crummy AM section. Generally, I don't expect most of the
manufacturers to do much design. They like to use as many industry standard
parts as possible. If the crummy AM section becomes the industry standard
part, it will greately drive down the manufacturing volume of the better
part, even if there's only a nickel's difference at the start.

Back in the AA5 days, there was a AA4 which didn't use an IF amplifier tube
or a second IF transformer. They were around, but they were known poor
performers and not very popular.

Another possibility is poor alignment, especially with ceramic filters.
Inexpensive ceramic filters might not fall exactly on their nominal
frequency. I have a Realistic DX-100 like that. I suppose it was factory
aligned at 455 kHz, but the IF had a double peak. I realigned it to the
center frequency of the ceramic filter and the adjacent channel rejection
got much better and the sensitivity went up. Doing a careful alignment
takes a little extra time but the manufacturers hate that sort of thing,
especially on assembly lines.





I noticed Doug Smith's post on the increase in noise and interference.
Those are important points and he's right.


Agreed.




What modern (new or used) AM radio can I buy that can pull in distant
stations?

I have a Realistic DX440, which does a good job. Others have tried and
like
the GE superradio and CC radio. The GE is much less expensive.


SuperRadio III is a very good AMDX machine, but the dial pointer is
certainly not the last word in accuracy. Still, with a good longwire,
or even a select-a-tenna, it gives excellent performance. My AMDX log
from my shack here in SW Michigan is 112 verified stations so far with
the Superadio III, and I'm not done covering the bands from all
directions yet.

Tony

Just have to count those 10kHz steps, especially if you're DXing in the
dark!

Frank Dresser