Will two table radios always be in phase, out of phase/...

[micky]

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom. Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other. Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar. But what about within the radio, when the
heterodyning frequency starts. What if it starts have a cycle after the
first radio?



**So I bought the second radio. The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all. (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times. Aren\'t switches supposed to last into the
millions of times? --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works. The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

 

[Ed Cryer]

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom. Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other. Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar. But what about within the radio, when the
heterodyning frequency starts. What if it starts have a cycle after the
first radio?



**So I bought the second radio. The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all. (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times. Aren\'t switches supposed to last into the
millions of times? --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works. The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

 

[Ed Cryer]

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom. Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other. Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar. But what about within the radio, when the
heterodyning frequency starts. What if it starts have a cycle after the
first radio?



**So I bought the second radio. The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all. (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times. Aren\'t switches supposed to last into the
millions of times? --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works. The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

 

[Ed Cryer]

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom. Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other. Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar. But what about within the radio, when the
heterodyning frequency starts. What if it starts have a cycle after the
first radio?



**So I bought the second radio. The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all. (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times. Aren\'t switches supposed to last into the
millions of times? --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works. The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

 

[Ed Cryer]

Ed Cryer wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom.  Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other.  Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar.   But what about within the radio, when the
heterodyning frequency starts.  What if it starts have a cycle after the
first radio?



**So I bought the second radio.  The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all.  (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times.  Aren\'t switches supposed to last into the
millions of times?  --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works.  The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no
explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

My best radio is in my bathroom. I didn\'t put it there; it was in place
when I moved in; it comes through the vent fan which switches on with
the room switch.
I\'ve been trying to figure out for years which station it\'s tuned to.
Mostly it seems classical, like a choir singing, but now and again it
has a bom-da-da-bom rhythm of rock music. I once heard it playing
Werewolves of London.

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Ed

 

[Ed Cryer]

Ed Cryer wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom.  Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other.  Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar.   But what about within the radio, when the
heterodyning frequency starts.  What if it starts have a cycle after the
first radio?



**So I bought the second radio.  The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all.  (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times.  Aren\'t switches supposed to last into the
millions of times?  --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works.  The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no
explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

My best radio is in my bathroom. I didn\'t put it there; it was in place
when I moved in; it comes through the vent fan which switches on with
the room switch.
I\'ve been trying to figure out for years which station it\'s tuned to.
Mostly it seems classical, like a choir singing, but now and again it
has a bom-da-da-bom rhythm of rock music. I once heard it playing
Werewolves of London.

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Ed

 

[Ed Cryer]

Ed Cryer wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?

And why is it low frequencies are famous for cancelling out when out of
phase when high frequencies are just as likely, 0.5, I think, to cancel
each other out?

Can I just turn off one radio and turn it on again so that the total
odds over both times have increased that by the second time the radios
will be in phase?


I have a radio and tv in one bathroom but neither in the other, which is
smaller and adjoins the bedroom.  Sometimes I want to hear the radio
which only gets \'loud\' if you are in the same room. I can hear it from
the bathroom but not enough to understand what is said.

I have another table radio, KLM, expensive, that I had for about 33
years when the speaker switch started to fail**, and I turn that one on
too, to the same station, also at maximum volume, and I can hear in the
bathroom just fine, but I wonder if some frequencies are out of phase
from one radio to the other, cancelling each other, and I\'m not hearing
them.

It seems to me, if one radio is farther from the transmitting antenna,
by 1/2 wave length, the speakers in the two radios will always be going
in the opposite direction from each other.  Maybe.

In my case, the radios are one above the other, so the distance from the
xmtr is very similar.   But what about within the radio, when the
heterodyning frequency starts.  What if it starts have a cycle after the
first radio?



**So I bought the second radio.  The first one has a pushbutton switch
meant to connect/disconnect a wooden-cabinet stereo speaker, which I
have no room for, and unless I get the switch just right, no sound comes
out at all.  (even the on/off momementary contact switch no longer works
well, after only 33 years, maybe using it at most 6 times a day, so that
6x365x33=66,000 times.  Aren\'t switches supposed to last into the
millions of times?  --- It\'s failing isn\'t nearly as bad, because I just
keep pushing until it works.  The speaker switch OTOH has a spring that
pushes it out, past its sweet spot, so now it\'s hard to get to connect
at all.

Let\'s rule out Hertzian waves from Net speeds to begin with. If you have
an FM radio and a Wifi radio in the same room, there\'ll be a very
noticeable discrepancy.
This phenomenon is so well known that I don\'t need linger on the cause.

Added to that, you may have two wifi radios together, but processed by
different hardware/ software. And here again the cause needs no
explanation.

Your second radio with the dodgy on/off button doesn\'t even contribute
to the mix; and it won\'t do so until it produces some output sound. A
faulty switch is a different problem from an echoing, out-of-sync
cacophony of sound.

Ed

My best radio is in my bathroom. I didn\'t put it there; it was in place
when I moved in; it comes through the vent fan which switches on with
the room switch.
I\'ve been trying to figure out for years which station it\'s tuned to.
Mostly it seems classical, like a choir singing, but now and again it
has a bom-da-da-bom rhythm of rock music. I once heard it playing
Werewolves of London.

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Ed

 

[micky]

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

 

[micky]

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

 

[micky]

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

 

[rbowman]

On Sun, 25 Dec 2022 21:29:49 +0000, Ed Cryer wrote:

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Don\'t you have another radio? It would be trivial to scan the frequencies
until you get a match. Doesn\'t the UK require broadcast stations to
periodically identify themselves?

https://www.transmissionzero.co.uk/radio/london-pirate-radio/

Perhaps it\'s a pirate with eclectic taste. The local university has a low
power FM station that\'s all over the map depending on who the DJ is for
the slot.

 

[rbowman]

On Sun, 25 Dec 2022 21:29:49 +0000, Ed Cryer wrote:

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Don\'t you have another radio? It would be trivial to scan the frequencies
until you get a match. Doesn\'t the UK require broadcast stations to
periodically identify themselves?

https://www.transmissionzero.co.uk/radio/london-pirate-radio/

Perhaps it\'s a pirate with eclectic taste. The local university has a low
power FM station that\'s all over the map depending on who the DJ is for
the slot.

 

[rbowman]

On Sun, 25 Dec 2022 21:29:49 +0000, Ed Cryer wrote:

If you solve your problem, let me know. I\'d love to find out which
station my bathroom is tuned into.

Don\'t you have another radio? It would be trivial to scan the frequencies
until you get a match. Doesn\'t the UK require broadcast stations to
periodically identify themselves?

https://www.transmissionzero.co.uk/radio/london-pirate-radio/

Perhaps it\'s a pirate with eclectic taste. The local university has a low
power FM station that\'s all over the map depending on who the DJ is for
the slot.

 

[Martin Brown]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

The radio will convert it to DC anyway so that doesn\'t matter.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

Chances are one will be a few hundred ns time shifted relative to the
other since the amplifiers in each stage of detection are unlikely to
have exactly the same delay or frequency phase response.

Propagation of sound waves in the room will have a much larger effect on
what you hear. Positioning of the speakers relative to hard surfaces.

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

If you really want massive flanging effects try two different digital
radios or SDR decoders within earshot. The difference in delays then can
be fractions of a second or seconds when compared to an FM radio.

DAB is completely useless in an emergency situation unless you have a
shed load of batteries. Uses a set every 8 hours of run time. A decent
FM radio will run for a week or more on just one set of batteries.

--
Regards,
Martin Brown

 

[Martin Brown]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

The radio will convert it to DC anyway so that doesn\'t matter.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

Chances are one will be a few hundred ns time shifted relative to the
other since the amplifiers in each stage of detection are unlikely to
have exactly the same delay or frequency phase response.

Propagation of sound waves in the room will have a much larger effect on
what you hear. Positioning of the speakers relative to hard surfaces.

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

If you really want massive flanging effects try two different digital
radios or SDR decoders within earshot. The difference in delays then can
be fractions of a second or seconds when compared to an FM radio.

DAB is completely useless in an emergency situation unless you have a
shed load of batteries. Uses a set every 8 hours of run time. A decent
FM radio will run for a week or more on just one set of batteries.

--
Regards,
Martin Brown

 

[Martin Brown]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

The radio will convert it to DC anyway so that doesn\'t matter.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

Chances are one will be a few hundred ns time shifted relative to the
other since the amplifiers in each stage of detection are unlikely to
have exactly the same delay or frequency phase response.

Propagation of sound waves in the room will have a much larger effect on
what you hear. Positioning of the speakers relative to hard surfaces.

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

If you really want massive flanging effects try two different digital
radios or SDR decoders within earshot. The difference in delays then can
be fractions of a second or seconds when compared to an FM radio.

DAB is completely useless in an emergency situation unless you have a
shed load of batteries. Uses a set every 8 hours of run time. A decent
FM radio will run for a week or more on just one set of batteries.

--
Regards,
Martin Brown

 

[Clive Arthur]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

I would expect two radios of the same make and model to be in phase, but
different radios will have different amplifier designs and speaker
arrangements which will likely give phase differences at different
frequencies. Plus it is possible that the two loudspeakers are simply
connected in opposite polarity anyway.

--
Cheers
Clive

 

[Clive Arthur]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

I would expect two radios of the same make and model to be in phase, but
different radios will have different amplifier designs and speaker
arrangements which will likely give phase differences at different
frequencies. Plus it is possible that the two loudspeakers are simply
connected in opposite polarity anyway.

--
Cheers
Clive

 

[Clive Arthur]

On 25/12/2022 22:55, micky wrote:

In alt.home.repair, on Sun, 25 Dec 2022 16:56:38 -0500, Rachelle
Walenski <rw@2.Ø> wrote:

micky wrote:

Technical qustion about wave valleys and troughs and if two radio
playing the same station will be in phase wrt all frequencies, or if
some will cancel out?


Are the radios powered by the same 120v phase or on opposite legs (180
degree out-of-phase)?

Yes, plugged into the same outlet.

Both are traditional over-the-air AM-FM radios, usually using FM. (One
has bluetooth but it\'s not in use. )

(To other poster, The radio with the bad speaker switch works well if
the switch stops in the right spot, and sometimes it will stay that way
for days. No access for contact cleaner at the moment.

I would expect two radios of the same make and model to be in phase, but
different radios will have different amplifier designs and speaker
arrangements which will likely give phase differences at different
frequencies. Plus it is possible that the two loudspeakers are simply
connected in opposite polarity anyway.

--
Cheers
Clive

 

[server]

On Sun, 25 Dec 2022 17:55:35 -0500, micky <NONONOmisc07@fmguy.com>
wrote:

Both are traditional over-the-air AM-FM radios, usually using FM.

Even if two radios produce in phase audio on AM (with equal number of
audio inverting stages) the radio may produce opposite phase audio on
FM. One might have the local oscillator (LO) below the received
frequency (RF), while in the other the LO is above the RF frequency.