Cato wrote:

Greetings: I certainly appreciate everyones opinion on my question
about the similarity or difference in reception of two radios of the
same manufacturer and model number.
It appears from the reply so far, that if one was to sit down
with any two such radios, and did a side by side comparison, it should
come as no surprise if there are small differences in reception
sensitivity, selectivity etc., and we should just accept that fact and
live with it.
But in most cases, as price and quality of components go up,
variations in reception between two radios of the same manufacturer
and model number should become less.
If any one else has any comments on this topic, I will certainly
be interested in reading them.

Regards, Cato


Even if the radio are the same, or nearly so, another challenge is how to
make the measurements accurately. If you are scanning the band to see what
one picks up vs. another, unless the radios are on the same antenna, and
scanning frequencies at exactly the same time there will be observed
differences. This is just because any fading of any signal being revived
can affect the results. In comparing radios for real world results, you
will have trouble because the real world is constantly changing.

If you use lab equipment to make the measurements then you have a much
better chance at seeing differences in radios. At least your measurements
will be more consistent. However, then you would need to relate the lab
measurements to real world application.

I wouldn't be overly concerned about componenet tolerances. A good designer
would understand the component variations and either specify proper
components or design the circuit so that it is not that sensitive to
component variations. On many circuits the variations of components are not
that critical. (A few are, but many are not.) So generic comments about
component variation are not important. What is important is looking at
those component values that really do matter.

Alignment can matter significantly, especially in front end circuits. I've
seen lots of performance variation in AM radios because the tracking
between antenna, RF, and oscillator tuning was bad. If you look at the
circuits in many modern radios, you'll find designs that also minimize the
need for critical alignment.

craigm