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am/narrow-fm/wide-fm/lsb/usb what else?
there has to be some other modes that normal scanners wouldn't decode.
any thoughts? |
am/narrow-fm/wide-fm/lsb/usb what else?
Digital?
wrote in message ups.com... there has to be some other modes that normal scanners wouldn't decode. any thoughts? |
am/narrow-fm/wide-fm/lsb/usb what else?
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am/narrow-fm/wide-fm/lsb/usb what else?
On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett"
said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. |
am/narrow-fm/wide-fm/lsb/usb what else?
On Fri, 30 Sep 2005 11:29:31 -0400, Al Klein wrote:
On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett" said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. Actually "Digital" is C4FM. -- Korbin Dallas The name was changed to protect the guilty. |
am/narrow-fm/wide-fm/lsb/usb what else?
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am/narrow-fm/wide-fm/lsb/usb what else?
On Sat, 01 Oct 2005 01:43:09 GMT, Korbin Dallas
said in rec.radio.scanner: On Fri, 30 Sep 2005 11:29:31 -0400, Al Klein wrote: On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett" said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. Actually "Digital" is C4FM. And the modulation on the carrier is??? AM? PM?? FM?? What bandwidth is it? There's a difference between the process of putting information on the carrier and the format that information comes in. The OP was asking about the physical layer, as specified by "AM/FM ..." etc.. |
am/narrow-fm/wide-fm/lsb/usb what else?
On Fri, 30 Sep 2005 23:45:46 -0400, Al Klein wrote:
On Sat, 01 Oct 2005 01:43:09 GMT, Korbin Dallas said in rec.radio.scanner: On Fri, 30 Sep 2005 11:29:31 -0400, Al Klein wrote: On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett" said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. Actually "Digital" is C4FM. And the modulation on the carrier is??? AM? PM?? FM?? What bandwidth is it? There's a difference between the process of putting information on the carrier and the format that information comes in. The OP was asking about the physical layer, as specified by "AM/FM ..." etc.. The standard is APCO 25, which defines BW to be 6Khz and Modulation as C4FM. For more details see: http://www.apcointl.org/frequency/project25/ -- Korbin Dallas The name was changed to protect the guilty. |
am/narrow-fm/wide-fm/lsb/usb what else?
On Sat, 01 Oct 2005 19:48:00 GMT, Korbin Dallas
said in rec.radio.scanner: On Fri, 30 Sep 2005 23:45:46 -0400, Al Klein wrote: On Sat, 01 Oct 2005 01:43:09 GMT, Korbin Dallas said in rec.radio.scanner: On Fri, 30 Sep 2005 11:29:31 -0400, Al Klein wrote: On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett" said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. Actually "Digital" is C4FM. And the modulation on the carrier is??? AM? PM?? FM?? What bandwidth is it? There's a difference between the process of putting information on the carrier and the format that information comes in. The OP was asking about the physical layer, as specified by "AM/FM ..." etc.. The standard is APCO 25, which defines BW to be 6Khz and Modulation as C4FM. Again - what's the physical layer? Id the frequency of the carrier changed? The amplitude? The phase? Some other characteristic of it? The OP wasn't asking about the logical layer (which is where C4FM sits), he was asking about the physical layer. |
am/narrow-fm/wide-fm/lsb/usb what else?
i guess i was trying to find out how many ways signal can be modulated.
even if the signal is digital, isn't it still modulated in fm? |
am/narrow-fm/wide-fm/lsb/usb what else?
|
am/narrow-fm/wide-fm/lsb/usb what else?
When I think about what parameters of a carrier could be controlled with a
modulating signal, there's amplitude, frequency, phase, and waveshape, and there are numerous ways to modulate these parameters, both continuous and discrete. An example of waveshape modulation would be pulsewidth modulation (PWM). It is possible to encode information digitally by modulating any of those four parameters...it doesn't have to be FM. With more sophistication, you could modulate more than one parameter at a time to get more information out of a given bandwidth. Have a look at "modulation" in Wikipedia (http://en.wikipedia.org/wiki/Modulation). - Doug wrote in message oups.com... i guess i was trying to find out how many ways signal can be modulated. even if the signal is digital, isn't it still modulated in fm? |
am/narrow-fm/wide-fm/lsb/usb what else?
|
am/narrow-fm/wide-fm/lsb/usb what else?
On Sat, 01 Oct 2005 17:49:28 -0400, Al Klein wrote:
On Sat, 01 Oct 2005 19:48:00 GMT, Korbin Dallas said in rec.radio.scanner: On Fri, 30 Sep 2005 23:45:46 -0400, Al Klein wrote: On Sat, 01 Oct 2005 01:43:09 GMT, Korbin Dallas said in rec.radio.scanner: On Fri, 30 Sep 2005 11:29:31 -0400, Al Klein wrote: On Fri, 30 Sep 2005 13:35:23 GMT, "Jim Hackett" said in rec.radio.scanner: Digital? Most of what we call "digital" is NFM or SNFM. Actually "Digital" is C4FM. And the modulation on the carrier is??? AM? PM?? FM?? What bandwidth is it? There's a difference between the process of putting information on the carrier and the format that information comes in. The OP was asking about the physical layer, as specified by "AM/FM ..." etc.. The standard is APCO 25, which defines BW to be 6Khz and Modulation as C4FM. Again - what's the physical layer? Id the frequency of the carrier changed? The amplitude? The phase? Some other characteristic of it? The OP wasn't asking about the logical layer (which is where C4FM sits), he was asking about the physical layer. Gee I don't know, Since it has FM in the NAME maybe its FM. Or perhaps you prefer the Emission designator of 8K10F1E. I always thought Modulation and Channel access methods are typically placed at layer 1. -- Korbin Dallas The name was changed to protect the guilty. |
am/narrow-fm/wide-fm/lsb/usb what else?
On Mon, 03 Oct 2005 23:28:37 GMT, Korbin Dallas
said in rec.radio.scanner: On Sat, 01 Oct 2005 17:49:28 -0400, Al Klein wrote: Again - what's the physical layer? Id the frequency of the carrier changed? The amplitude? The phase? Some other characteristic of it? The OP wasn't asking about the logical layer (which is where C4FM sits), he was asking about the physical layer. Gee I don't know, Since it has FM in the NAME maybe its FM. Or perhaps you prefer the Emission designator of 8K10F1E. Point, head, whoosh. I always thought Modulation and Channel access methods are typically placed at layer 1. Modulation is layer 1. "Channel access"? Wazzat? PL? |
am/narrow-fm/wide-fm/lsb/usb what else?
On 29 Sep 2005 21:18:12 -0700, wrote:
there has to be some other modes that normal scanners wouldn't decode. any thoughts? ISB, DSB ? DRM? |
am/narrow-fm/wide-fm/lsb/usb what else?
On Tue, 04 Oct 2005 10:39:59 GMT, (Peter Newman)
said in rec.radio.scanner: On 29 Sep 2005 21:18:12 -0700, wrote: there has to be some other modes that normal scanners wouldn't decode. any thoughts? ISB, DSB ? Any receiver that will receive SSB will also receive DSB, since both sidebands are the same. ISB too, but only 1 at a time. |
am/narrow-fm/wide-fm/lsb/usb what else?
On Wed, 05 Oct 2005 21:18:23 -0400, Al Klein
wrote: On Tue, 04 Oct 2005 10:39:59 GMT, (Peter Newman) said in rec.radio.scanner: On 29 Sep 2005 21:18:12 -0700, wrote: there has to be some other modes that normal scanners wouldn't decode. any thoughts? ISB, DSB ? Any receiver that will receive SSB will also receive DSB, since both sidebands are the same. ISB too, but only 1 at a time. Only if the IF is narrow enough to keep the other sideband out, otherwise you get both at once..... |
am/narrow-fm/wide-fm/lsb/usb what else?
On Thu, 06 Oct 2005 20:37:32 -0700, matt weber
said in rec.radio.scanner: On Wed, 05 Oct 2005 21:18:23 -0400, Al Klein wrote: On Tue, 04 Oct 2005 10:39:59 GMT, (Peter Newman) said in rec.radio.scanner: On 29 Sep 2005 21:18:12 -0700, wrote: there has to be some other modes that normal scanners wouldn't decode. any thoughts? ISB, DSB ? Any receiver that will receive SSB will also receive DSB, since both sidebands are the same. ISB too, but only 1 at a time. Only if the IF is narrow enough to keep the other sideband out, otherwise you get both at once..... A SSB receiver is one that has a bandwidth narrow enough to receive only 1 sideband. If it's 6 KHz wide it's a DSB receiver. (Yes, almost any ham receiver is either SSB or DSB, depending on the filter you have running at the moment.) Of course finding DSBSC signals on the air today is a bit difficult. (They used to be much more prevalent, but ARC5s are expensive antiques today, not cheap transmitters. And is there still 1 operational DSB-100?) |
am/narrow-fm/wide-fm/lsb/usb what else?
Al Klein wrote: On Thu, 06 Oct 2005 20:37:32 -0700, matt weber said in rec.radio.scanner: On Wed, 05 Oct 2005 21:18:23 -0400, Al Klein wrote: On Tue, 04 Oct 2005 10:39:59 GMT, (Peter Newman) said in rec.radio.scanner: On 29 Sep 2005 21:18:12 -0700, wrote: there has to be some other modes that normal scanners wouldn't decode. any thoughts? ISB, DSB ? Any receiver that will receive SSB will also receive DSB, since both sidebands are the same. ISB too, but only 1 at a time. Only if the IF is narrow enough to keep the other sideband out, otherwise you get both at once..... A SSB receiver is one that has a bandwidth narrow enough to receive only 1 sideband. If it's 6 KHz wide it's a DSB receiver. (Yes, almost any ham receiver is either SSB or DSB, depending on the filter you have running at the moment.) Of course finding DSBSC signals on the air today is a bit difficult. (They used to be much more prevalent, but ARC5s are expensive antiques today, not cheap transmitters. And is there still 1 operational DSB-100?) You can't assume that any filter over 3kHz or so is symetrical about the 'carrier' frequency just because that is the normal configuation of consumer equipment. Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. I don't know how much DSB is still on the air but a quick google search for "double side band' gets over 12 million hits. It may not be encountered in normal voice communications on HF and scanner frequencies but it is hiding in other places and frequencies from a quick look at some of the hits. Dave |
am/narrow-fm/wide-fm/lsb/usb what else?
On Sat, 08 Oct 2005 21:17:44 -0400, Dave Holford
said in rec.radio.scanner: You can't assume that any filter over 3kHz or so is symetrical about the 'carrier' frequency just because that is the normal configuation of consumer equipment. You can't assume that any given SSB signal will fit in a 3 KHz bandwidth, just because all current signals do. But I can assume that all filters currently in production are symmetrical about the center frequency within 10% - because they all are. Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. I don't know how much DSB is still on the air but a quick google search for "double side band' gets over 12 million hits. It may not be encountered in normal voice communications on HF and scanner frequencies but it is hiding in other places and frequencies from a quick look at some of the hits. I said DSBSC, not DSB. There's loads of DSB on the air today, it's just not DSBSC. |
am/narrow-fm/wide-fm/lsb/usb what else?
Al Klein wrote:
On Sat, 08 Oct 2005 21:17:44 -0400, Dave Holford said in rec.radio.scanner: You can't assume that any filter over 3kHz or so is symetrical about the 'carrier' frequency just because that is the normal configuation of consumer equipment. You can't assume that any given SSB signal will fit in a 3 KHz bandwidth, just because all current signals do. But I can assume that all filters currently in production are symmetrical about the center frequency within 10% - because they all are. Certainly most current crystal filters are symmetrical about the centre frequency, as are most people symmetrical about the centre (externally at least, and I'm not going to quibble about the orientation since I'm sure you know what I mean) - I wrote 'carrier' frequency. I'm not sure about current mechanicals (somewhere I have an old Collins filter catalog with asymmetrical SSB curves). Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. As I stated in my first posting, a Winradio. The rest of the paragraph is true if you are talking about 'the standard filtered superhet SSB receiver' provided that it is also fitted with AM filters which can be used in the SSB mode - not universally true. I can do it with my TS-450 but not my IC-706 for example. Not all receivers have the ability to select mode and filter independently. I don't know how much DSB is still on the air but a quick google search for "double side band' gets over 12 million hits. It may not be encountered in normal voice communications on HF and scanner frequencies but it is hiding in other places and frequencies from a quick look at some of the hits. I said DSBSC, not DSB. There's loads of DSB on the air today, it's just not DSBSC. True, my mistake in assuming DSBRC or DSBSC. Here I am trying to make a simple point that one should not assume that just because a situation is common in one's own experience it is universal; and I make an assumption - Hoist with my own Petard! And, I can't help noting how a simple point can grow into a complex discussion of differing views - I guess that's how politics and the law got started! Dave |
am/narrow-fm/wide-fm/lsb/usb what else?
On Sun, 09 Oct 2005 10:50:22 -0400, Dave Holford
said in rec.radio.scanner: Al Klein wrote: But I can assume that all filters currently in production are symmetrical about the center frequency within 10% - because they all are. Certainly most current crystal filters Mechanical filters, ceramic filters, lumped-constant filters, op-amp filters ... any discrete piece of hardware that's supposed to pass a band of frequencies in the IF of a modern (within the last 40 years or so) receiver. are symmetrical about the centre frequency, as are most people symmetrical about the centre (externally at least, and I'm not going to quibble about the orientation since I'm sure you know what I mean) - I wrote 'carrier' frequency. If you put the carrier (no need for tics - carrier whether suppressed or not) at the center of the filter's bandpass, the filter is symmetrical about the carrier - if you put the carrier outside the bandpass of the filter are you going to claim that bandpass filters don't pass signals? The filter is symmetrical about any signal centered in the bandpass if the filter has a symmetrical bandpass - by definition. I'm not sure about current mechanicals (somewhere I have an old Collins filter catalog with asymmetrical SSB curves). Within 10%? None of mine were ever that distorted, although some of the Collins filters were about the most asymmetrical filters I've ever seen. They were designed that way. But the receivers were designed to work with "asymmetrical" filters. Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. As I stated in my first posting, a Winradio. Oh, you mean that a DSP is capable of not hearing the opposite sideband. Nothing to do with filters. "Filtering" isn't always done by "filters". The rest of the paragraph is true if you are talking about 'the standard filtered superhet SSB receiver' provided that it is also fitted with AM filters which can be used in the SSB mode - not universally true. I can do it with my TS-450 but not my IC-706 for example. Not all receivers have the ability to select mode and filter independently. And my Honda can't receive ISB either. If we're comparing fruits, chickens don't count. |
am/narrow-fm/wide-fm/lsb/usb what else?
Al Klein wrote: On Sun, 09 Oct 2005 10:50:22 -0400, Dave Holford said in rec.radio.scanner: Al Klein wrote: But I can assume that all filters currently in production are symmetrical about the center frequency within 10% - because they all are. Certainly most current crystal filters Mechanical filters, ceramic filters, lumped-constant filters, op-amp filters ... any discrete piece of hardware that's supposed to pass a band of frequencies in the IF of a modern (within the last 40 years or so) receiver. are symmetrical about the centre frequency, as are most people symmetrical about the centre (externally at least, and I'm not going to quibble about the orientation since I'm sure you know what I mean) - I wrote 'carrier' frequency. If you put the carrier (no need for tics - carrier whether suppressed or not) at the center of the filter's bandpass, the filter is symmetrical about the carrier - if you put the carrier outside the bandpass of the filter are you going to claim that bandpass filters don't pass signals? The filter is symmetrical about any signal centered in the bandpass if the filter has a symmetrical bandpass - by definition. I'm not sure about current mechanicals (somewhere I have an old Collins filter catalog with asymmetrical SSB curves). Within 10%? None of mine were ever that distorted, although some of the Collins filters were about the most asymmetrical filters I've ever seen. They were designed that way. But the receivers were designed to work with "asymmetrical" filters. Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. As I stated in my first posting, a Winradio. Oh, you mean that a DSP is capable of not hearing the opposite sideband. Nothing to do with filters. "Filtering" isn't always done by "filters". The rest of the paragraph is true if you are talking about 'the standard filtered superhet SSB receiver' provided that it is also fitted with AM filters which can be used in the SSB mode - not universally true. I can do it with my TS-450 but not my IC-706 for example. Not all receivers have the ability to select mode and filter independently. And my Honda can't receive ISB either. If we're comparing fruits, chickens don't count. You are saying exactly what I've been saying, except that you want to argue about it. Gotta go, lunch is ready. Dave |
am/narrow-fm/wide-fm/lsb/usb what else?
Al Klein wrote: On Sun, 09 Oct 2005 10:50:22 -0400, Dave Holford said in rec.radio.scanner: Al Klein wrote: But I can assume that all filters currently in production are symmetrical about the center frequency within 10% - because they all are. Certainly most current crystal filters Mechanical filters, ceramic filters, lumped-constant filters, op-amp filters ... any discrete piece of hardware that's supposed to pass a band of frequencies in the IF of a modern (within the last 40 years or so) receiver. are symmetrical about the centre frequency, as are most people symmetrical about the centre (externally at least, and I'm not going to quibble about the orientation since I'm sure you know what I mean) - I wrote 'carrier' frequency. If you put the carrier (no need for tics - carrier whether suppressed or not) at the center of the filter's bandpass, the filter is symmetrical about the carrier - if you put the carrier outside the bandpass of the filter are you going to claim that bandpass filters don't pass signals? The filter is symmetrical about any signal centered in the bandpass if the filter has a symmetrical bandpass - by definition. I'm not sure about current mechanicals (somewhere I have an old Collins filter catalog with asymmetrical SSB curves). Within 10%? None of mine were ever that distorted, although some of the Collins filters were about the most asymmetrical filters I've ever seen. They were designed that way. But the receivers were designed to work with "asymmetrical" filters. Just for fun I am currently listening to an LSB conversation on 3763 kHz with a 7.5 kHz filter and I cannot hear any sign of the conversation on 3765 - but, the noise is a bit higher due to the wider filter. I wouldn't normally do this but just had to try it. Of course, if I select DSB or ISB I get both signals, although the 3765 conversation is inverted and shifted in frequency. With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. As I stated in my first posting, a Winradio. Oh, you mean that a DSP is capable of not hearing the opposite sideband. Nothing to do with filters. "Filtering" isn't always done by "filters". The rest of the paragraph is true if you are talking about 'the standard filtered superhet SSB receiver' provided that it is also fitted with AM filters which can be used in the SSB mode - not universally true. I can do it with my TS-450 but not my IC-706 for example. Not all receivers have the ability to select mode and filter independently. And my Honda can't receive ISB either. If we're comparing fruits, chickens don't count. You are saying exactly what I've been saying, except that you want to argue about it. Gotta go, lunch is ready. Dave |
am/narrow-fm/wide-fm/lsb/usb what else?
On Sun, 09 Oct 2005 10:50:22 -0400, Dave Holford
wrote: With what receiver and which filter? What kind of detector? I can design any number of receivers that will do what you claim, but that doesn't negate the fact that the standard filtered superhet SSB receiver will receive a signal on the "wrong" sideband if the filter is wide enough and the detector is set correctly. As I stated in my first posting, a Winradio. Yes, the WinRadio G303 and G313 appear to be the only commercially available eceivers with genuine ISB and DSB modes. The DSB is actually so good that you can receive standard AM with it and can hardly hear any difference (i.e. the digital BFO inserts the carrier spot on frequency, like with synchronous AM mode). I did an interesting experiment with my G303e/PD by using stereo speakers in DSB mode on an AM broadcast station, and you can actually hear a phase difference variation between the two sidebands. This causes an amazing "floating in space" audio sensation. Peter |
am/narrow-fm/wide-fm/lsb/usb what else?
Peter Newman wrote: On Sun, 09 Oct 2005 10:50:22 -0400, Dave Holford wrote: As I stated in my first posting, a Winradio. Yes, the WinRadio G303 and G313 appear to be the only commercially available eceivers with genuine ISB and DSB modes. The DSB is actually so good that you can receive standard AM with it and can hardly hear any difference (i.e. the digital BFO inserts the carrier spot on frequency, like with synchronous AM mode). I did an interesting experiment with my G303e/PD by using stereo speakers in DSB mode on an AM broadcast station, and you can actually hear a phase difference variation between the two sidebands. This causes an amazing "floating in space" audio sensation. Peter I have the same setup and also found that DSB on AM fascinating. I have used ISB to set the master oscillator on frequency. Tuned to WWV, ideally on 20 MHz, one can hear the beat between the two sidebands and adjust the frequency until the beat is zero, or at least less than 1 Hz, then this figure is used to offset the oscillator. I have been pleasantly surprised with the stability of the receiver. From a cold start through to several hours of operation the drift is substantially less than 10 Hz. That, along with the spectrum analysis capability and the almost infinitely adjustable filters makes it a most interesting tool/toy. Regards Dave |
am/narrow-fm/wide-fm/lsb/usb what else?
On Mon, 10 Oct 2005 18:56:48 -0400, Dave Holford
wrote: As I stated in my first posting, a Winradio. Yes, the WinRadio G303 and G313 appear to be the only commercially available eceivers with genuine ISB and DSB modes. The DSB is actually so good that you can receive standard AM with it and can hardly hear any difference (i.e. the digital BFO inserts the carrier spot on frequency, like with synchronous AM mode). I did an interesting experiment with my G303e/PD by using stereo speakers in DSB mode on an AM broadcast station, and you can actually hear a phase difference variation between the two sidebands. This causes an amazing "floating in space" audio sensation. Peter I have the same setup and also found that DSB on AM fascinating. I have used ISB to set the master oscillator on frequency. Tuned to WWV, ideally on 20 MHz, one can hear the beat between the two sidebands and adjust the frequency until the beat is zero, or at least less than 1 Hz, then this figure is used to offset the oscillator. This is a very good method. In fact I used CW for this (old habits die hard), but I agree it is much easier with ISB. I have been pleasantly surprised with the stability of the receiver. From a cold start through to several hours of operation the drift is substantially less than 10 Hz. I found that too. The G303e manufacturer's specs says 10ppm frequency stability, but I have found it to be much better than specified, at least within my home temperature range. That, along with the spectrum analysis capability and the almost infinitely adjustable filters makes it a most interesting tool/toy. Agreed. It is also fun to use. This radio brought me back to the hobby, after a few years of absence. Peter |
am/narrow-fm/wide-fm/lsb/usb what else?
Peter Newman wrote: On Mon, 10 Oct 2005 18:56:48 -0400, Dave Holford wrote: As I stated in my first posting, a Winradio. Yes, the WinRadio G303 and G313 appear to be the only commercially available eceivers with genuine ISB and DSB modes. The DSB is actually so good that you can receive standard AM with it and can hardly hear any difference (i.e. the digital BFO inserts the carrier spot on frequency, like with synchronous AM mode). I did an interesting experiment with my G303e/PD by using stereo speakers in DSB mode on an AM broadcast station, and you can actually hear a phase difference variation between the two sidebands. This causes an amazing "floating in space" audio sensation. Peter I have the same setup and also found that DSB on AM fascinating. I have used ISB to set the master oscillator on frequency. Tuned to WWV, ideally on 20 MHz, one can hear the beat between the two sidebands and adjust the frequency until the beat is zero, or at least less than 1 Hz, then this figure is used to offset the oscillator. This is a very good method. In fact I used CW for this (old habits die hard), but I agree it is much easier with ISB. I have been pleasantly surprised with the stability of the receiver. From a cold start through to several hours of operation the drift is substantially less than 10 Hz. I found that too. The G303e manufacturer's specs says 10ppm frequency stability, but I have found it to be much better than specified, at least within my home temperature range. That, along with the spectrum analysis capability and the almost infinitely adjustable filters makes it a most interesting tool/toy. Agreed. It is also fun to use. This radio brought me back to the hobby, after a few years of absence. Peter I find that I use the Winradio far more than my other receivers, and if I can find the money I think a VHF/UHF Winradiio would add a lot of versatility to my listening above HF as well. Regards Dave |
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