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Can I sense a bright star pointing an eight foot antenna towards it?
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I am an amateur optical astronomer.
If I connect an eight foot yagi or other comparable sized antenna to my oscilloscope and point the antenna at a bright star will I see a voltage on my oscilloscope?
I am not interested in turning the voltage into an image just wondering if I would see a voltage increase when it is on a bright star. I’d like to know your thoughts before I take the time to build the antenna. I’m thinking about in the 25cm range. I’ve heard that’s an active area. My oscilloscope will read down to about 20 millivolts.
star radio-astronomy radio-telescope
edited 12 mins ago
Trilarion
1234
asked 9 hours ago
Lambda
1233
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Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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up vote
4
down vote
favorite
I am an amateur optical astronomer.
If I connect an eight foot yagi or other comparable sized antenna to my oscilloscope and point the antenna at a bright star will I see a voltage on my oscilloscope?
I am not interested in turning the voltage into an image just wondering if I would see a voltage increase when it is on a bright star. I’d like to know your thoughts before I take the time to build the antenna. I’m thinking about in the 25cm range. I’ve heard that’s an active area. My oscilloscope will read down to about 20 millivolts.
star radio-astronomy radio-telescope
edited 12 mins ago
Trilarion
1234
asked 9 hours ago
Lambda
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
4
down vote
favorite
up vote
4
down vote
favorite
I am an amateur optical astronomer.
If I connect an eight foot yagi or other comparable sized antenna to my oscilloscope and point the antenna at a bright star will I see a voltage on my oscilloscope?
I am not interested in turning the voltage into an image just wondering if I would see a voltage increase when it is on a bright star. I’d like to know your thoughts before I take the time to build the antenna. I’m thinking about in the 25cm range. I’ve heard that’s an active area. My oscilloscope will read down to about 20 millivolts.
star radio-astronomy radio-telescope
edited 12 mins ago
Trilarion
1234
asked 9 hours ago
Lambda
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I am an amateur optical astronomer.
If I connect an eight foot yagi or other comparable sized antenna to my oscilloscope and point the antenna at a bright star will I see a voltage on my oscilloscope?
I am not interested in turning the voltage into an image just wondering if I would see a voltage increase when it is on a bright star. I’d like to know your thoughts before I take the time to build the antenna. I’m thinking about in the 25cm range. I’ve heard that’s an active area. My oscilloscope will read down to about 20 millivolts.
star radio-astronomy radio-telescope
star radio-astronomy radio-telescope
edited 12 mins ago
Trilarion
1234
asked 9 hours ago
Lambda
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 12 mins ago
Trilarion
1234
asked 9 hours ago
Lambda
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 12 mins ago
Trilarion
1234
edited 12 mins ago
Trilarion
1234
edited 12 mins ago
Trilarion
1234
1234
asked 9 hours ago
Lambda
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 9 hours ago
Lambda
1233
asked 9 hours ago
Lambda
1233
1233
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Lambda is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
add a comment |Â
2 Answers
2
active
oldest
votes
up vote
8
down vote
accepted
Stars are too dim for amateur radio equipment. There are two possible radio sources that you can detect: the sun and Jupiter.
Jupiter is particularly interesting as interactions between Io and its magnetic field produce beams of radio waves that sweep past earth every 10 hours. These are detectable in the amateur range, at about 20 MHz.
Nasa make a kit for detecting these radio signals, or it is possible to use a ham antenna, but of course it must be cut for the frequency of operation. The Nasa kit uses a phased dipole antenna which must be set up in a field or similar as the antenna is about 7m long.
Stars are not very good radio sources. Supernovae remnants such as Cassiopeia A or the Crab nebula are much brighter at radio wavelengths.
answered 8 hours ago
James K
30.2k243100
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
add a comment |Â
up vote
0
down vote
Connecting an antenna directly to oscilloscope will not give reception, even with a strong radio source.
First problem is the power level. Typical received power from antenna would be around -100 dBm, i.e. $10^-10,textrmmW$. A typical oscilloscope has an input impedance of 1 Mohm, which means if all the received power went there, it would give a voltage of $sqrt10^-10,textrmmWcdot1,textrmMohm approx 0.3,textrmmV$. With the minimum scale of 20 mV, you wouldn't see much anything.
The second problem is mismatch loss. Most antennas are matched to 50 ohm impedance instead of the 1 Mohm. The mismatch means that only about 0.01% of the power would actually go into the oscilloscope, the rest would reflect back.
answered 25 mins ago
jpa
1612
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
8
down vote
accepted
Stars are too dim for amateur radio equipment. There are two possible radio sources that you can detect: the sun and Jupiter.
Jupiter is particularly interesting as interactions between Io and its magnetic field produce beams of radio waves that sweep past earth every 10 hours. These are detectable in the amateur range, at about 20 MHz.
Nasa make a kit for detecting these radio signals, or it is possible to use a ham antenna, but of course it must be cut for the frequency of operation. The Nasa kit uses a phased dipole antenna which must be set up in a field or similar as the antenna is about 7m long.
Stars are not very good radio sources. Supernovae remnants such as Cassiopeia A or the Crab nebula are much brighter at radio wavelengths.
answered 8 hours ago
James K
30.2k243100
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
add a comment |Â
up vote
8
down vote
accepted
Stars are too dim for amateur radio equipment. There are two possible radio sources that you can detect: the sun and Jupiter.
Jupiter is particularly interesting as interactions between Io and its magnetic field produce beams of radio waves that sweep past earth every 10 hours. These are detectable in the amateur range, at about 20 MHz.
Nasa make a kit for detecting these radio signals, or it is possible to use a ham antenna, but of course it must be cut for the frequency of operation. The Nasa kit uses a phased dipole antenna which must be set up in a field or similar as the antenna is about 7m long.
Stars are not very good radio sources. Supernovae remnants such as Cassiopeia A or the Crab nebula are much brighter at radio wavelengths.
answered 8 hours ago
James K
30.2k243100
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
add a comment |Â
up vote
8
down vote
accepted
up vote
8
down vote
accepted
Stars are too dim for amateur radio equipment. There are two possible radio sources that you can detect: the sun and Jupiter.
Jupiter is particularly interesting as interactions between Io and its magnetic field produce beams of radio waves that sweep past earth every 10 hours. These are detectable in the amateur range, at about 20 MHz.
Nasa make a kit for detecting these radio signals, or it is possible to use a ham antenna, but of course it must be cut for the frequency of operation. The Nasa kit uses a phased dipole antenna which must be set up in a field or similar as the antenna is about 7m long.
Stars are not very good radio sources. Supernovae remnants such as Cassiopeia A or the Crab nebula are much brighter at radio wavelengths.
answered 8 hours ago
James K
30.2k243100
Stars are too dim for amateur radio equipment. There are two possible radio sources that you can detect: the sun and Jupiter.
Jupiter is particularly interesting as interactions between Io and its magnetic field produce beams of radio waves that sweep past earth every 10 hours. These are detectable in the amateur range, at about 20 MHz.
Nasa make a kit for detecting these radio signals, or it is possible to use a ham antenna, but of course it must be cut for the frequency of operation. The Nasa kit uses a phased dipole antenna which must be set up in a field or similar as the antenna is about 7m long.
Stars are not very good radio sources. Supernovae remnants such as Cassiopeia A or the Crab nebula are much brighter at radio wavelengths.
answered 8 hours ago
James K
30.2k243100
answered 8 hours ago
James K
30.2k243100
answered 8 hours ago
James K
30.2k243100
answered 8 hours ago
James K
30.2k243100
30.2k243100
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
add a comment |Â
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
Thank you. Would and amateur setup get a signal from supernova?
– Lambda
8 hours ago
1
1
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
@Lambda that's an interesting question, so it's better to ask as a new question so that someone will have room to post a new answer.
– uhoh
7 hours ago
add a comment |Â
up vote
0
down vote
Connecting an antenna directly to oscilloscope will not give reception, even with a strong radio source.
First problem is the power level. Typical received power from antenna would be around -100 dBm, i.e. $10^-10,textrmmW$. A typical oscilloscope has an input impedance of 1 Mohm, which means if all the received power went there, it would give a voltage of $sqrt10^-10,textrmmWcdot1,textrmMohm approx 0.3,textrmmV$. With the minimum scale of 20 mV, you wouldn't see much anything.
The second problem is mismatch loss. Most antennas are matched to 50 ohm impedance instead of the 1 Mohm. The mismatch means that only about 0.01% of the power would actually go into the oscilloscope, the rest would reflect back.
answered 25 mins ago
jpa
1612
add a comment |Â
up vote
0
down vote
Connecting an antenna directly to oscilloscope will not give reception, even with a strong radio source.
First problem is the power level. Typical received power from antenna would be around -100 dBm, i.e. $10^-10,textrmmW$. A typical oscilloscope has an input impedance of 1 Mohm, which means if all the received power went there, it would give a voltage of $sqrt10^-10,textrmmWcdot1,textrmMohm approx 0.3,textrmmV$. With the minimum scale of 20 mV, you wouldn't see much anything.
The second problem is mismatch loss. Most antennas are matched to 50 ohm impedance instead of the 1 Mohm. The mismatch means that only about 0.01% of the power would actually go into the oscilloscope, the rest would reflect back.
answered 25 mins ago
jpa
1612
add a comment |Â
up vote
0
down vote
up vote
0
down vote
Connecting an antenna directly to oscilloscope will not give reception, even with a strong radio source.
First problem is the power level. Typical received power from antenna would be around -100 dBm, i.e. $10^-10,textrmmW$. A typical oscilloscope has an input impedance of 1 Mohm, which means if all the received power went there, it would give a voltage of $sqrt10^-10,textrmmWcdot1,textrmMohm approx 0.3,textrmmV$. With the minimum scale of 20 mV, you wouldn't see much anything.
The second problem is mismatch loss. Most antennas are matched to 50 ohm impedance instead of the 1 Mohm. The mismatch means that only about 0.01% of the power would actually go into the oscilloscope, the rest would reflect back.
answered 25 mins ago
jpa
1612
Connecting an antenna directly to oscilloscope will not give reception, even with a strong radio source.
First problem is the power level. Typical received power from antenna would be around -100 dBm, i.e. $10^-10,textrmmW$. A typical oscilloscope has an input impedance of 1 Mohm, which means if all the received power went there, it would give a voltage of $sqrt10^-10,textrmmWcdot1,textrmMohm approx 0.3,textrmmV$. With the minimum scale of 20 mV, you wouldn't see much anything.
The second problem is mismatch loss. Most antennas are matched to 50 ohm impedance instead of the 1 Mohm. The mismatch means that only about 0.01% of the power would actually go into the oscilloscope, the rest would reflect back.
answered 25 mins ago
jpa
1612
answered 25 mins ago
jpa
1612
answered 25 mins ago
jpa
1612
answered 25 mins ago
jpa
1612
1612
add a comment |Â
add a comment |Â
Lambda is a new contributor. Be nice, and check out our Code of Conduct.
Lambda is a new contributor. Be nice, and check out our Code of Conduct.
Lambda is a new contributor. Be nice, and check out our Code of Conduct.
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