Rob Mills wrote:
"Lucky" wrote in message
...


So are you saying the GE Super Radio II {2} is the best one GE makes for
shortwave??

Can you please elaborate on why the radio impressed you so much? What are
the features that make this radio still talked about today?



I have the Super 1 (7-2880a) and it beat the socks off of my early (I
assume it's an early one since I have had it for about 10 yr) Super3. The
one pulls in MW stations that the three wasn't even getting. Never use it
for FM so can't evaluate the FM side
As near as I can tell there are only minor differences between the one and
two, the two has a tweeter which the one's do not. The very early one (mine)
does not have external antenna connections while the later ones and the two
do.
I also have Radio Shacks attempt to copy the GE Super and it isn't even in
the race, actually it sounds like a radio with a squelch that is set quite
deep, it's just another nice sounding portable that's good for local use
only. RM~





As I recall, GE SupeRadio is a superhet. RS's attempt is a TRF.
There will be substantial differences in DX performance.

About 30 years ago, Popular Electronics had an article about an AM
radio on a single chip. The chip is a ZN414 (three leads, power, common
and RF in), at the time available from Circuit Specialists, Tempe, AZ,
and with a tuning stage added, produced a very nice tuner/preamp for a
TRF receiver. I bought three of them for a pittance, and built one up in
a previously gutted Charles Freshman case bought at an auction as part
of a lot of TRF's my mother in law paid $1 for. Using the tuning coils
and caps which were attached to the front panel, and a piece of
breadboard to hold the chip and battery, I built up a solidstate TRF in
a 1924 Freshman case. (the other 8 radios have been restored over the
years, and work daily, btw)

The sensitivity was far more than I expected out of this chip. With
only the tuning coils in the case, I got all the locals, and many
stations at considerable distance. From my location in St Louis, I got
WGN, and WLS, as well as several of the regional station in and aroud
the midwest. Of course this was before NRSC-II, so stations were still
transmitting full bandwidth. KMOX on Sunday nights did a couple of pop
music shows. And the audio was magnificent.

Not so much, with station specs today.

With a random length of wire antenna, the band came alive. But
selectivity was too wide to make much sense out of most of it.

Even a wideband superhet like my McKay-Dymek AM-5 could separate more
signals from the mess than this ZN414.

But on locals, like the RS TRF Super Radio, it was, and still is, a
very pleasant and solid performing receiver.

For those who will doubtless ask, ZN414 has been discontinued. Some
years it was upgraded to ZN414A, which lowered noise, increased gain.
But that, too has been supplanted by yet another chip that's still
current, though the designation escapes me.

Do a websearch for ZN414, you'll come up with some interesting results.

The current chip is available from Circuit Specialists.

D Peter Maus ) writes:
Rob Mills wrote:
"Lucky" wrote in message
...


So are you saying the GE Super Radio II {2} is the best one GE makes for
shortwave??

Can you please elaborate on why the radio impressed you so much? What are
the features that make this radio still talked about today?



I have the Super 1 (7-2880a) and it beat the socks off of my early (I
assume it's an early one since I have had it for about 10 yr) Super3. The
one pulls in MW stations that the three wasn't even getting. Never use it
for FM so can't evaluate the FM side
As near as I can tell there are only minor differences between the one and
two, the two has a tweeter which the one's do not. The very early one (mine)
does not have external antenna connections while the later ones and the two
do.
I also have Radio Shacks attempt to copy the GE Super and it isn't even in
the race, actually it sounds like a radio with a squelch that is set quite
deep, it's just another nice sounding portable that's good for local use
only. RM~





As I recall, GE SupeRadio is a superhet. RS's attempt is a TRF.
There will be substantial differences in DX performance.

I don't think this is true. While TRF, ie Tuned Radio Frequency, was
used to denote a receiver with a couple of tuned amplifier stages
going into a detector stage decades ago, I think the TRF in the Radio
Shack radio was a marketing thing. At least the term. I was always
under the impression that the TRF was indeed a superheterodyne design,
but unlike many/most portable radios, had a stage of tuned amplification
ahead of the mixer, and that Tuned RF stage is what the name refers to.

For that level of radio, it was something relatively unique. It wasn't
unique to receivers that were primarily shortwave receivers, and it
wasn't unique for car radios, but most lower end am receivers, certainly
portables and maybe even a lot of home base receivers (the famed All
American Five had not stage ahead of the mixer for isntance) did not
have that extra stage.

Done well, the extra stage would help reject images, and improve sensitivity.


About 30 years ago, Popular Electronics had an article about an AM
radio on a single chip. The chip is a ZN414 (three leads, power, common
and RF in), at the time available from Circuit Specialists, Tempe, AZ,
and with a tuning stage added, produced a very nice tuner/preamp for a
TRF receiver.

The point of the ZN414, and the later MK484, is that by having good AGC
there is vast improvement over a what one would expect for a single tuned
circuit receiver. In effect, turn down the gain when a decent signal
is there, and as long as adjacent signals were weaker to start off, they
are now way down.

I wonder how you used it as a preamp, given that the design doesn't really
make for using it for anything but a TRF receiver. Only three pins, so
the output comes after the detector stage.

Michael

About a year or a little less ago,I saw an article at www.gizmodo.com
about a radar system had been created on a chip about the size of a
U.S.coin.I suppose a search on the internet might turn up something
about that.
cuhulin

Michael Black wrote:
D Peter Maus ) writes:

Rob Mills wrote:

"Lucky" wrote in message
...



So are you saying the GE Super Radio II {2} is the best one GE makes for
shortwave??

Can you please elaborate on why the radio impressed you so much? What are
the features that make this radio still talked about today?



I have the Super 1 (7-2880a) and it beat the socks off of my early (I
assume it's an early one since I have had it for about 10 yr) Super3. The
one pulls in MW stations that the three wasn't even getting. Never use it
for FM so can't evaluate the FM side
As near as I can tell there are only minor differences between the one and
two, the two has a tweeter which the one's do not. The very early one (mine)
does not have external antenna connections while the later ones and the two
do.
I also have Radio Shacks attempt to copy the GE Super and it isn't even in
the race, actually it sounds like a radio with a squelch that is set quite
deep, it's just another nice sounding portable that's good for local use
only. RM~





As I recall, GE SupeRadio is a superhet. RS's attempt is a TRF.
There will be substantial differences in DX performance.


I don't think this is true. While TRF, ie Tuned Radio Frequency, was
used to denote a receiver with a couple of tuned amplifier stages
going into a detector stage decades ago, I think the TRF in the Radio
Shack radio was a marketing thing. At least the term. I was always
under the impression that the TRF was indeed a superheterodyne design,
but unlike many/most portable radios, had a stage of tuned amplification
ahead of the mixer, and that Tuned RF stage is what the name refers to.

For that level of radio, it was something relatively unique. It wasn't
unique to receivers that were primarily shortwave receivers, and it
wasn't unique for car radios, but most lower end am receivers, certainly
portables and maybe even a lot of home base receivers (the famed All
American Five had not stage ahead of the mixer for isntance) did not
have that extra stage.

Done well, the extra stage would help reject images, and improve sensitivity.



About 30 years ago, Popular Electronics had an article about an AM
radio on a single chip. The chip is a ZN414 (three leads, power, common
and RF in), at the time available from Circuit Specialists, Tempe, AZ,
and with a tuning stage added, produced a very nice tuner/preamp for a
TRF receiver.


The point of the ZN414, and the later MK484, is that by having good AGC
there is vast improvement over a what one would expect for a single tuned
circuit receiver. In effect, turn down the gain when a decent signal
is there, and as long as adjacent signals were weaker to start off, they
are now way down.

I wonder how you used it as a preamp, given that the design doesn't really
make for using it for anything but a TRF receiver. Only three pins, so
the output comes after the detector stage.


There is an AF gain stage before output on the chip. So only a line
level AF amp is necessary to drive the loudspeaker. It drives a high
impedance headset quite nicely. When I first put it together I used a
pair of Brush Clevites. Later I used my first pair or HD414's which were
also 2k

A single AA standard Eveready would last 90 days 24/7 at the time.

A Duracell more than twice that.

D Peter Maus ) writes:
Michael Black wrote:

I wonder how you used it as a preamp, given that the design doesn't really
make for using it for anything but a TRF receiver. Only three pins, so
the output comes after the detector stage.


There is an AF gain stage before output on the chip. So only a line
level AF amp is necessary to drive the loudspeaker. It drives a high
impedance headset quite nicely. When I first put it together I used a
pair of Brush Clevites. Later I used my first pair or HD414's which were
also 2k

Sorry, I now see I misread the part about a preamp. On first reading,
"produced a very nice tuner/preamp for a TRF receiver" came to me
as you used it ahead of a TRF receiver.

Michael