AM receiver chips?

P

Pete Klammer

Guest
I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately?
 
Pete posted:

<< I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately? >>

Yes there are some IC's for AM an AM radio, but I don't have the part ID's
handy. If you do not receive replies with the part info, I will find and post
them later.

Is the transmitted signal unmodulated?

I have an affinity for people who do the outdoor thing and occasionally need
help. If you need design help, you can email me direct, or post the request
here and many people will likely respond with help.

Don
 
Pete Klammer wrote:

I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately?
Once upon a time there was this

http://www.hewett.norfolk.sch.uk/curric/techweb/epscweb/dsheets/zn416.pdf

Doesn't seem to be current though sadly. You might get some old stock though.


Graham
 
"Pete Klammer" <PKlammer@NETRONICS-PE.com> wrote in message
news:7_6dnUdgEtwJflzcRVn-tA@comcast.com...
I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this
is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately?
How about the ZN414 , 1 chip AM receiver with AGC and detector, runs of 1.5
V

Wim
>
 
I read in sci.electronics.design that Wim Ton <wimton@blueyonder.co.uk>
wrote (in <UNxwd.8$Rf4.0@fe2.news.blueyonder.co.uk>) about 'AM receiver
chips?', on Fri, 17 Dec 2004:
"Pete Klammer" <PKlammer@NETRONICS-PE.com> wrote in message
news:7_6dnUdgEtwJflzcRVn-tA@comcast.com...
I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this
is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately?


How about the ZN414 , 1 chip AM receiver with AGC and detector, runs of 1.5
V

Is it still available? It's very old.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
I went through the AM radio IC's in the NTE catalog. There are lots of IC's
for RF/IF/mixer/agc, etc., but not much for low current operation.

Given it's AM and 457 kHz., I believe a TRF design would be excellent, as the
current can be minimized. The NTE1055 IF looks usable, but a good OP amp may
be as good if coupled with a AGC at the front-end.

For those looking for a complete "AM Tuner Subsystem" check out the NTE1214 (RF
amp, osc, mixer, 3 IF amps, AGC, tune meter output).

Don
 
I have used the MK484 in several designs, ranging from as low as 300khz
to as high as 5 mhz. It is very versatile, if you are willing to
experiment. It is easy to use, gives great results, and for those that
like to tinker, a great all-around AM receiver tool. You can search for
both suppliers and circuit details on Google. Well worth the try.
 
artswan posted:

<< I have used the MK484 in several designs, ranging from as low as 300khz
to as high as 5 mhz. It is very versatile, if you are willing to
experiment. It is easy to use, gives great results, and for those that
like to tinker, a great all-around AM receiver tool. You can search for
both suppliers and circuit details on Google. Well worth the try. >>

I agree it looks very good, but I could not find a supplier except for very
small quantities, AND I found several link to people wanting to buy one. I
don't like to design around something that already looks obsolete.

Did you find a good supply?

Don
 
On Fri, 17 Dec 2004 20:06:46 +0000, Dbowey wrote:

I went through the AM radio IC's in the NTE catalog. There are lots of IC's
for RF/IF/mixer/agc, etc., but not much for low current operation.

Given it's AM and 457 kHz., I believe a TRF design would be excellent, as the
current can be minimized. The NTE1055 IF looks usable, but a good OP amp may
be as good if coupled with a AGC at the front-end.

For those looking for a complete "AM Tuner Subsystem" check out the NTE1214 (RF
amp, osc, mixer, 3 IF amps, AGC, tune meter output).
I'm kind of surprised that nobody's mentioned how close 457KHz is to
455KHz, which has been a standard IF in broadcast AM receivers since there
have been superhets. So all you need is a good front end, which you could
get in the ARRL handbook, and any standard IF strip with a little tuning.

Or is it just stupid obvious?

Cheers!
Rich
 
Rich Grise posted:

<< On Fri, 17 Dec 2004 20:06:46 +0000, Dbowey wrote:

I went through the AM radio IC's in the NTE catalog. There are lots of IC's
for RF/IF/mixer/agc, etc., but not much for low current operation.

Given it's AM and 457 kHz., I believe a TRF design would be excellent, as the
current can be minimized. The NTE1055 IF looks usable, but a good OP amp may
be as good if coupled with a AGC at the front-end.

For those looking for a complete "AM Tuner Subsystem" check out the NTE1214
(RF
amp, osc, mixer, 3 IF amps, AGC, tune meter output).
I'm kind of surprised that nobody's mentioned how close 457KHz is to
455KHz, which has been a standard IF in broadcast AM receivers since there
have been superhets. So all you need is a good front end, which you could
get in the ARRL handbook, and any standard IF strip with a little tuning.
I think it's only obvious to people who have been exposed to superhets,
technically. I plan to use IF cans for setting the bandwidth following the
loop antenna, if needed. However, the Q of the loop may be enough all by
itself.

Don
 
In article <7_6dnUdgEtwJflzcRVn-tA@comcast.com>,
Pete Klammer <PKlammer@NETRONICS-PE.com> wrote:
I would like to pick up on-off keyed AM at 457kHz (avalanche rescue
frequency) with great sensitivity, selectivity, and low power. Since this is
just below the broadcast band, I'm hoping to find a single-chip receiver
that can be tuned there. Have you come across any such animals lately?
Try Atmel, they make what used to be Telefunken chips.
Also Philips.

You could also use a narrowband FM IF chip (Philips, On Semi.?) especially
if it has the RSSI output (which is a logarithmic signal strength).

If it's a straight CW (not modulated, except for the keying) signal, a
Direct Conversion receiver may be a good option. These are very common in
amateur radio circles. The idea is to use a mixer to convert the signal
directly down to the audio range, and have most the the receiver's gain
in the audio amplifier.

Mark Zenier mzenier@eskimo.com Washington State resident
 
On 19 Dec 2004 04:10:38 GMT, dbowey@aol.com (Dbowey) wroth:

I got off an order for some zn416's and a couple similar units to see what they
can do before doing an OP amp design. All of the "ZN"one chip receivers appear
to be obsolete. However, I found good PDF spec sheets for them.

If anyone has good knowledge of the transmitted signal, please share.

Thanks
Don
Sorry for getting into the thread so late... I'm using Analog Device's
AD607 single-chip receiver in a project at work. It's a complete superhet
design intended for cellphones. The IF/demodulator section is all I'm using for
a 8.5 MHz TRF AM receiver. The bandwidth of the IF covers 400 KHz to 12 MHz.
It's working very well so far. Digi-Key sells them for $7.30 in quantities of
one.

If you want to play with it I can supply hints about using it.

Jim
 
James Meyer posted:

<< On 19 Dec 2004 04:10:38 GMT, dbowey@aol.com (Dbowey) wroth:

I got off an order for some zn416's and a couple similar units to see what
they
can do before doing an OP amp design. All of the "ZN"one chip receivers
appear
to be obsolete. However, I found good PDF spec sheets for them.

If anyone has good knowledge of the transmitted signal, please share.

Thanks
Don
Sorry for getting into the thread so late... I'm using Analog Device's
AD607 single-chip receiver in a project at work. It's a complete superhet
design intended for cellphones. The IF/demodulator section is all I'm using
for
a 8.5 MHz TRF AM receiver. The bandwidth of the IF covers 400 KHz to 12 MHz.
It's working very well so far. Digi-Key sells them for $7.30 in quantities of
one.
Thanks for the offer. I wii fetch the specs on the AD607 and get back to you.


Don
 

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