What is a heterodyne.....
 

.....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Thanks,
C-

What is a heterodyne.....
 

"coustanis" ) writes:
....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Did you look in a dictionary for the basic definitions? Even if the
dictionary doesn't give a technical explanation, it should help you
when adding the context of radio around it.

A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

So when two stations are too close together, their carriers will beat
together to cause a beat note in your receiver. If one is at 1MHz, and
the other at 1.001MHz, then you get a 1KHz beat note. This is one reason
AM broadcast stations are 10KHz apart. It's high enough that it will
be out of hearing range for most people, and high enough that if it's
a bother one can filter it out without really bothering the actual
contents of the modulation.

The less structured a service is, the more likely the heterodynes. Listen
to CB when the band is open, and it's full of beat notes, because the
stations aren't all on the same frequency. (Amateur radio bands could
also be the case, but when single sideband replaced AM, the carriers
which are what beat together disappeared.)

A beat note sounds like an audio note, because it's the difference of
two higher frequencies. You'd only hear the audio beats, because of
the frequency response of the receiver, and your hearing range. They
won't sound exotice because they aren't. They may vary in amplitude,
if the stations that are causing the heterodyne are varying in amplitude.

If you've got a receiver with a BFO, turn it on while listening to an AM
station. You will hear the heterodyne, or beat note, of the BFO and
the station's carrier. Vary the BFO tuning, and the frequency of
the beat will change.

Tune to a CW (ie a code station) and turn on the BFO, and what originally
sounded like thumping or the on and off of noise, is now a tone. The
BFO heterodyned the keyed carrier down to an audio frequency, where
you can hear it.

A superheterodyne receiver, which must be what you are thinking of,
just extends this idea. It heterodynes the incoming signal to an
intermediate frequency, where it can better be amplified and filtered,
before going on to further stages of heterodyning, or the ultimate
detection to audio.

Michael

What is a heterodyne.....
 

On 10 Nov 2005 17:55:14 GMT, (Michael Black)
wrote:


"coustanis" ) writes:
....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Did you look in a dictionary for the basic definitions? Even if the
dictionary doesn't give a technical explanation, it should help you
when adding the context of radio around it.

A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

So when two stations are too close together, their carriers will beat
together to cause a beat note in your receiver. If one is at 1MHz, and
the other at 1.001MHz, then you get a 1KHz beat note. This is one reason
AM broadcast stations are 10KHz apart. It's high enough that it will
be out of hearing range for most people, and high enough that if it's
a bother one can filter it out without really bothering the actual
contents of the modulation.

The less structured a service is, the more likely the heterodynes. Listen
to CB when the band is open, and it's full of beat notes, because the
stations aren't all on the same frequency. (Amateur radio bands could
also be the case, but when single sideband replaced AM, the carriers
which are what beat together disappeared.)

A beat note sounds like an audio note, because it's the difference of
two higher frequencies. You'd only hear the audio beats, because of
the frequency response of the receiver, and your hearing range. They
won't sound exotice because they aren't. They may vary in amplitude,
if the stations that are causing the heterodyne are varying in amplitude.

If you've got a receiver with a BFO, turn it on while listening to an AM
station. You will hear the heterodyne, or beat note, of the BFO and
the station's carrier. Vary the BFO tuning, and the frequency of
the beat will change.

Tune to a CW (ie a code station) and turn on the BFO, and what originally
sounded like thumping or the on and off of noise, is now a tone. The
BFO heterodyned the keyed carrier down to an audio frequency, where
you can hear it.

A superheterodyne receiver, which must be what you are thinking of,
just extends this idea. It heterodynes the incoming signal to an
intermediate frequency, where it can better be amplified and filtered,
before going on to further stages of heterodyning, or the ultimate
detection to audio.

Michael

It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

What is a heterodyne.....
 

No, I didn't think to look in the dictionary. I just posted a radio
related topic to a radio related group.
Please accept my apology for my shortsightedness.
I apologize.
I appreciate your detailed explanation. That was nice of you to go to
the trouble.

Have a great day,

C-

What is a heterodyne.....
 

Michael Black wrote:
"coustanis" ) writes:
....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Did you look in a dictionary for the basic definitions? Even if the
dictionary doesn't give a technical explanation, it should help you
when adding the context of radio around it.

A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

So when two stations are too close together, their carriers will beat
together to cause a beat note in your receiver. If one is at 1MHz, and
the other at 1.001MHz, then you get a 1KHz beat note. This is one reason
AM broadcast stations are 10KHz apart. It's high enough that it will
be out of hearing range for most people, and high enough that if it's
a bother one can filter it out without really bothering the actual
contents of the modulation.

The less structured a service is, the more likely the heterodynes. Listen
to CB when the band is open, and it's full of beat notes, because the
stations aren't all on the same frequency. (Amateur radio bands could
also be the case, but when single sideband replaced AM, the carriers
which are what beat together disappeared.)

A beat note sounds like an audio note, because it's the difference of
two higher frequencies. You'd only hear the audio beats, because of
the frequency response of the receiver, and your hearing range. They
won't sound exotice because they aren't. They may vary in amplitude,
if the stations that are causing the heterodyne are varying in amplitude.

If you've got a receiver with a BFO, turn it on while listening to an AM
station. You will hear the heterodyne, or beat note, of the BFO and
the station's carrier. Vary the BFO tuning, and the frequency of
the beat will change.

Tune to a CW (ie a code station) and turn on the BFO, and what originally
sounded like thumping or the on and off of noise, is now a tone. The
BFO heterodyned the keyed carrier down to an audio frequency, where
you can hear it.

A superheterodyne receiver, which must be what you are thinking of,
just extends this idea. It heterodynes the incoming signal to an
intermediate frequency, where it can better be amplified and filtered,
before going on to further stages of heterodyning, or the ultimate
detection to audio.

Michael

What is a heterodyne.....
 

Michael Black wrote:
"coustanis" ) writes:
....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Did you look in a dictionary for the basic definitions? Even if the
dictionary doesn't give a technical explanation, it should help you
when adding the context of radio around it.

A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

So when two stations are too close together, their carriers will beat
together to cause a beat note in your receiver. If one is at 1MHz, and
the other at 1.001MHz, then you get a 1KHz beat note. This is one reason
AM broadcast stations are 10KHz apart. It's high enough that it will
be out of hearing range for most people, and high enough that if it's
a bother one can filter it out without really bothering the actual
contents of the modulation.

The less structured a service is, the more likely the heterodynes. Listen
to CB when the band is open, and it's full of beat notes, because the
stations aren't all on the same frequency. (Amateur radio bands could
also be the case, but when single sideband replaced AM, the carriers
which are what beat together disappeared.)

A beat note sounds like an audio note, because it's the difference of
two higher frequencies. You'd only hear the audio beats, because of
the frequency response of the receiver, and your hearing range. They
won't sound exotice because they aren't. They may vary in amplitude,
if the stations that are causing the heterodyne are varying in amplitude.

If you've got a receiver with a BFO, turn it on while listening to an AM
station. You will hear the heterodyne, or beat note, of the BFO and
the station's carrier. Vary the BFO tuning, and the frequency of
the beat will change.

Tune to a CW (ie a code station) and turn on the BFO, and what originally
sounded like thumping or the on and off of noise, is now a tone. The
BFO heterodyned the keyed carrier down to an audio frequency, where
you can hear it.

A superheterodyne receiver, which must be what you are thinking of,
just extends this idea. It heterodynes the incoming signal to an
intermediate frequency, where it can better be amplified and filtered,
before going on to further stages of heterodyning, or the ultimate
detection to audio.

Michael

What is a heterodyne.....
 

Michael Black wrote:
A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

Hams often describe their offspring as "harmonics". Some say that it
would be more appropirate to call them "heterodynes". If the children
were especailly wonderful, they would be "superheterodynes".

What is a heterodyne.....
 

wrote in message
oups.com...
Michael Black wrote:
A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.

Hams often describe their offspring as "harmonics". Some say that it
would be more appropirate to call them "heterodynes". If the children
were especailly wonderful, they would be "superheterodynes".


Or spurious emissions huh
Just kiddin

--
CL -- I doubt, therefore I might be !

What is a heterodyne.....
 

Many years ago,Superheterodyne Shortwave Radios were all the
rage,Shortwave Radios wise,that is.There were ads in magazines
gloryfying the advantages of Superheterodyne.Factory made and kits were
available,Superheterodyne Shortwave Radios.
Superheterodyne cuhulin

What is a heterodyne.....
 

) writes:
Many years ago,Superheterodyne Shortwave Radios were all the
rage,Shortwave Radios wise,that is.There were ads in magazines
gloryfying the advantages of Superheterodyne.Factory made and kits were
available,Superheterodyne Shortwave Radios.
Superheterodyne cuhulin

Maybe the newsgroup would be better if you didn't spew nonsense.
If you know nothing of a topic, don't bother posting.

Virtually every shortwave receiver in production today, and for many a
decade, is superheterodyne. They all convert the incoming signal
down to a fixed frequency for selectivity and amplification.

The exceptions would be fairly obscure kits, using regeneration,
or maybe some commercial amateur radio receivers or transceivers,
using direct conversion (which heterodynes, the incoming signal
directly down to audio).

You'd have to go back many decades before you hit a point where
a large percentage of shortwave receivers were regenerative. Go
back forty, and some would be regenerative, albeit they'd be at
the low cost end of the spectrum. Go back to the thirties, and
regeneration likely was still common, because superheterodyne designs
used more components and hence were too costly for many in the depression
era. Go back to the twenties, and besides cost there were still bugs
(the issue of images for instance), and maybe even a reluctance to move
to something new.

Once again, Howard Armstrong received the patent for the regenerative
receiver in 1914, US patent number 1,113,149,

He received the patent for the superheterodyne receiver in 1920, US
patent number 1,342,885.

And he received the patent for the superregenerative receiver in 1922,
US patent number 1,424,065.

Howard Armstrong took care of all basic receiver design beyond the
simple "crystal radio" and the TRF (Tuned Radio Frequency) receivers.
And took care of that by 1922.

Everything that came later were variants of those three (or more
like two, regen and superhet) basic concepts, incremental improvements
but no fourth type of receiver.

Michael

What is a heterodyne.....
 

Michael - thanks for these excellent and tidy thumbnail explanations
and histories. I guess I've long *sort of* known about these things,
but your concise posts encapsulate them beautifully and make them very
concrete.

Bruce Jensen

What is a heterodyne.....
 

It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

OK, I'll bite - why is this important in a world of radios that operate
on the heterodyne basis? And what makes a linear device different?
Are any commonly used radios linear devices?

Seriously!

Non-electronics guy Bruce Jensen

What is a heterodyne.....
 

Maybe so,but I have an Allied Radio catalog here,the 1941 Spring Summer
issue of the catalog and many of the radio ads in the catalog (which I
am looking at right now) do say things about Superhet (Superheterodyne)
and S-P-R-E-A-D band tuning and Regen and super Magna Beam antennas.
cuhulin

What is a heterodyne.....
 

Sometimes Cuhulin it is NOT who came up with invention first, but who
patented it (if such were available) and who best promoted it and marketed
it successfully.


Case in point
Marconi is credited with the invention of wireless (radio) 1895
and he was very good at promoting and marketing.

Others say it was Tesla.
By early 1895, Tesla was ready to transmit a signal 50 miles to West Point,
New York see URL:
http://www.pbs.org/tesla/ll/ll_whoradio.html

But one Mahlon Loomis did a successful wireless experiment in 1868 before
Marconi was born - 1874.
You can read about it at URL:
http://www.smecc.org/mhlon_loomis.htm

Few today have heard of Mahlon Loomis. Perhaps the world wasn't ready.



--
CL -- I doubt, therefore I might be !






wrote in message
...
www.devilfinder.com Old Superheterodyne Shortwave Radio
Advertisements

Shortwave History on the Net Stubblefield's Wireless.As many old,old
Superheterodyne Shortwave Radio advertisements as I have seen in
magazines and catalogs that date back to the 1940's and earlier,I know
they were eschewing the advantages of Superheterodyne Shortwave Radios,I
saw those old advertisements with my very own eyes,there isn't anything
wrong with my memory.The Wright Brothers did not invent the first engine
powered Aircraft either. www.devilfindr.com First Aircraft Flight
Pittsburg Texas
I once
read an article about probally Alexander Graham Bell didn't invent the
first Telephone,the article said a German guy in Germany did.Do you know
who really invented the first transistor? www.devilfinder.com Who
really invented the first transistor?

Eli Whitney didn't invent the Cotton Gin,Mrs.Green did.History is full
of Mishistory.
cuhulin

What is a heterodyne.....
 

David wrote:


It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

Yeah, that's extremely important all right. *yawn*

What is a heterodyne.....
 

Yep,I see what you mean.There is an article at
www.globalnewsmatrix.com about,Patent issued for anti.gravity device.
The guy may have a patent for an anti-gravity device,but he certainly is
not the first to invent or "discover" such a device,not by a long shot.I
have some old Popular Mechanics and Popular Science magazines here and
some of the magazines date back to about 1911 or before.One of the
magazines which dates back to around 1911 has an article about a
radio/vacuum tube a guy invented and the article goes on to mention that
within a very short distance of the tube,there is a flux that could lead
to the invention of an anti-gravity device.There is a company near
Huntsville,Alabama which has also created anti-gravity techonology
devices and a few years ago,I read an article about Boeing Aircraft
company claims to have anti-gravity devices too.Anti-gravity can not be
invented though,devices that can take advantage of anti-gravity can and
have been invented.
cuhulin

What is a heterodyne.....
 

wrote in message
ups.com...

David wrote:


It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

Yeah, that's extremely important all right. *yawn*


Let us hope your stereo hi-fi amplifier doesn't go non linear on you
(;-)

What is a heterodyne.....
 

coustanis wrote:
....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Thanks,
C-


homosexual from holland. nope that would be a homodane! dammit!

What is a heterodyne.....
 

On 10 Nov 2005 12:15:10 -0800, "bpnjensen"
wrote:

It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

OK, I'll bite - why is this important in a world of radios that operate
on the heterodyne basis? And what makes a linear device different?
Are any commonly used radios linear devices?

Seriously!

Non-electronics guy Bruce Jensen

An RF Preamp and Active Antenna electronics are 2 places where you
have a need for a linear active device.

What is a heterodyne.....
 

On 10 Nov 2005 14:05:42 -0800, wrote:


David wrote:


It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

Yeah, that's extremely important all right. *yawn*

It's an important concept in the radio world.

What is a heterodyne.....
 

www.radioblvd.com Those old radios were real works of Art,in and
out.And look at what excites some people nowdays,(but not me) the "fine
looks" of four bits worth of cheap plastic cabinet Eton1's and other
four bit plastic cabinet other brand names of other plastic radios and
they can't come even close to matching the sound of those big old
wonderfull tube type big speaker wooden cabinet Radios of long ago.
cuhulin

What is a heterodyne.....
 

Michael Black wrote:

You'd have to go back many decades before you hit a point where
a large percentage of shortwave receivers were regenerative. Go
back forty, and some would be regenerative, albeit they'd be at
the low cost end of the spectrum. Go back to the thirties, and
regeneration likely was still common, because superheterodyne designs
used more components and hence were too costly for many in the depression
era.

Nope, nearly all radios by the early 1930's were superhet.

What is a heterodyne.....
 

Brian Hill wrote:
"coustanis" wrote in message
oups.com...

....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Thanks,
C-



Basically, it's when your radio receives radio waves they travel through the
tuned circuits of the RF deck or front end and depending how you have the
dial set a specific frequency will emerge and travel into the mixer section
of your radio and combine with the locally generated frequency to produce a
new frequency that is more stable and it is equal to the sum or difference
of the two. Simply to combine two frequencies to create a new frequency. The
superhetrodyne is the basis for all modern receiver designs and uses this
technique.


Out of the mixer (sometimes referred to as the converter or 1st
detector) will be four frequencies. The fundemental frequency the set is
tuned to, the local oscillator frequency, and the sum and difference of
the two.

What is a heterodyne.....
 

On Thu, 10 Nov 2005 18:24:13 -0600, wrote:

www.radioblvd.com Those old radios were real works of Art,in and
out.And look at what excites some people nowdays,(but not me) the "fine
looks" of four bits worth of cheap plastic cabinet Eton1's and other
four bit plastic cabinet other brand names of other plastic radios and
they can't come even close to matching the sound of those big old
wonderfull tube type big speaker wooden cabinet Radios of long ago.
cuhulin

The Lowe HF-150 and the ICOM R-75 are both very nice pieces of
industrial design.

What is a heterodyne.....
 

On Thu, 10 Nov 2005 23:33:32 -0800, Cmdr Buzz Corey
wrote:

Brian Hill wrote:
"coustanis" wrote in message
oups.com...

....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Thanks,
C-



Basically, it's when your radio receives radio waves they travel through the
tuned circuits of the RF deck or front end and depending how you have the
dial set a specific frequency will emerge and travel into the mixer section
of your radio and combine with the locally generated frequency to produce a
new frequency that is more stable and it is equal to the sum or difference
of the two. Simply to combine two frequencies to create a new frequency. The
superhetrodyne is the basis for all modern receiver designs and uses this
technique.


Out of the mixer (sometimes referred to as the converter or 1st
detector) will be four frequencies. The fundemental frequency the set is
tuned to, the local oscillator frequency, and the sum and difference of
the two.
Plus intermod products of those 4 added and subtracted with each
other.

What is a homodyne.....
 

cuhulin? anyone?

What is a heterodyne.....
 

In article .com,
bpnjensen wrote:
It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

OK, I'll bite - why is this important in a world of radios that operate
on the heterodyne basis?

One important reason is that, in the real world, you can't have too much
gain in any one amplifier section, (in other words, on one frequency),
because the output of the amplifier can leak back to the input and the
circuit becomes an oscillator.

?And what makes a linear device different?
Are any commonly used radios linear devices?

The audio amplifier is designed to be a linear circuit. Another
word for heterodynes in an audio amplifier is "intermodulation
distortion".

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

What is a heterodyne.....
 

"Cmdr Buzz Corey" wrote in message
...
Brian Hill wrote:
"coustanis" wrote in message
oups.com...

....and what does it sound like?
I used to think it was a type of radio but since reading this group
I see it is a sound.

Thanks,
C-



Basically, it's when your radio receives radio waves they travel through
the tuned circuits of the RF deck or front end and depending how you have
the dial set a specific frequency will emerge and travel into the mixer
section of your radio and combine with the locally generated frequency to
produce a new frequency that is more stable and it is equal to the sum or
difference of the two. Simply to combine two frequencies to create a new
frequency. The superhetrodyne is the basis for all modern receiver
designs and uses this technique.


Out of the mixer (sometimes referred to as the converter or 1st detector)
will be four frequencies. The fundemental frequency the set is tuned to,
the local oscillator frequency, and the sum and difference of the two.

True but we were trying to keep it simple.

B.H.

What is a heterodyne.....
 

On Fri, 11 Nov 2005 19:05:50 GMT, (Mark Zenier)
wrote:

In article .com,
bpnjensen wrote:
It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.

OK, I'll bite - why is this important in a world of radios that operate
on the heterodyne basis?

One important reason is that, in the real world, you can't have too much
gain in any one amplifier section, (in other words, on one frequency),
because the output of the amplifier can leak back to the input and the
circuit becomes an oscillator.

?And what makes a linear device different?
Are any commonly used radios linear devices?

The audio amplifier is designed to be a linear circuit. Another
word for heterodynes in an audio amplifier is "intermodulation
distortion".



As in the important ''IP3'' measurement which shows how well the parts
that are supposed to be linear are behaving.

What is a heterodyne.....
 

"David" wrote

It's very important to point out that 2 different frequencies, when
mixed in a perfectly linear device, will not beat.


No, no, no! That's the Homodyne theory.

What is a heterodyne.....
 

Y'all laugh, but there really is such a thing as a homodyne receiver.

It works by amplifying the received signal so much that all modulation
is clipped off, giving just the carrier frequency which is then mixed
with the original signal via a product detector to recover the
modulation.