There's a guy in Atherton (NorCal) on Ebay who has several auctions for
these cheap little Sonys. Its the SONY ICF-S10MK2, AM/FM. I bought one
and darned if it wasn't easily the most sensitve pocket sized AM radio
of a dozen or so models I've tried. Now the Giants baseball station
comes in loud and clear anywhere around town, amazing.


The FM band was crap, distortion, no stereo, but AM performance highly
exceptional, as the auction shows it's kinda large, but it fits a shirt
pocket OK.

There was a really cool Sony unit I had several years ago............I think
it was the ICFS-5. The advertisement for this radio used to say "rediscover
the AM broadcast band". It sported an FET front end (two gang tuning), with
a Murata 6-element ceramic filter at 455kHz (CFWS455H). It didn't track too
well across the MW band, so I removed the antenna trimmer and used a
miniature Hammarlund air variable to peak the station. The radio had that
kind of slide rule drum dial similar to the Zenith Transoceanic radios, but
instead of switching frequency ranges, a new calibration scale would show
up, instead, showing station call letters for different regions of the USA.
The tuning needle was really cool................in the top center of the
needle was a tiny (read the size of the head of a pin) red LED, with tiny
green LEDs on each side of it. I gave it to a friend of mine several years
ago.........he still uses it to this day.

Pete

"Hatfield" wrote in message
oups.com...
There's a guy in Atherton (NorCal) on Ebay who has several auctions for
these cheap little Sonys. Its the SONY ICF-S10MK2, AM/FM. I bought one
and darned if it wasn't easily the most sensitve pocket sized AM radio
of a dozen or so models I've tried. Now the Giants baseball station
comes in loud and clear anywhere around town, amazing.


The FM band was crap, distortion, no stereo, but AM performance highly
exceptional, as the auction shows it's kinda large, but it fits a shirt
pocket OK.

It's true - it is an amazing little perfomer. Outperforms the Grundig Mini
300 and G1000A on mediumwave. Very thrifty on batteries too - I've been
listening for about 100 hours on the original set, still going strong.

I've always found it interesting the variation in MW performance amongst
pocket portables. What is it about this particular model that makes it
such a high AM performer, while models costing much more aren't - it isn't
as if Sony is aiming this at the hobby market or anything.

At any rate, it is certainly a worthy radio for anyone to have.

A few things.............either a broad band or tuned RF amp ahead of the
1st mixer. A tuned RF amp affords better image rejection, especially with
single conversion receivers that have only a 455kHz I.F. amplifier. I.F
coils and antenna coils wound with Litz wire are also helpful. A selective
I.F. strip, using either Litz wire wound coils or ceramic filters are good.
FETs in the input stage are good for cross-modulation rejection. Good audio
amplifier etc, etc, etc.
I hope this helps.

Pete

"Stranger_On_The_Bus" wrote in message
lkaboutradio.com...
It's true - it is an amazing little perfomer. Outperforms the Grundig
Mini
300 and G1000A on mediumwave. Very thrifty on batteries too - I've been
listening for about 100 hours on the original set, still going strong.

I've always found it interesting the variation in MW performance amongst
pocket portables. What is it about this particular model that makes it
such a high AM performer, while models costing much more aren't - it isn't
as if Sony is aiming this at the hobby market or anything.

At any rate, it is certainly a worthy radio for anyone to have.

One other thing I forgot to mention.............three point tracking of the
RF/Mixer/LO stages. This was done on some of the older higher end portables
that had the metal frame tuning capicators vs the newer miniature plastic
tuning caps. These older style caps had the outer plates in the tuning gangs
split in three or four parts (I don't remember exactly how many). This was
good, because instead of being limited to using the trimmer caps at the high
end of the band and the adjustment coils at the low end of the band, the
middle of the band could be compensated by bending those outer plates to
adjust this section.
Ulrich Rohde discusses three point tracking in his receiver design book.

Pete

"Stranger_On_The_Bus" wrote in message
lkaboutradio.com...
It's true - it is an amazing little perfomer. Outperforms the Grundig
Mini
300 and G1000A on mediumwave. Very thrifty on batteries too - I've been
listening for about 100 hours on the original set, still going strong.

I've always found it interesting the variation in MW performance amongst
pocket portables. What is it about this particular model that makes it
such a high AM performer, while models costing much more aren't - it isn't
as if Sony is aiming this at the hobby market or anything.

At any rate, it is certainly a worthy radio for anyone to have.