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Re: U3s first wspr
Finally, here it is after yet another reformatting
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On Fri, Jan 12, 2018 at 05:20 pm, Alan de G1FXB wrote: ? TrueBlue wrote: -I'm sort of curious how 3xBS170=200mW on 40m at 9V.? That's -about what you should get from one BS170 at ~5v on 40m. But that still doesn't explain why more voltage and more transistors, both, wouldn't increase output.? According to the link, it should. ?Hans spent some time writing up the theory of parallel operation. ??? "There are always minor variations between device characteristics from one transistor to the next. If these were bipolar NPN transistors, we would not be able to parallel them in this way. If one transistor takes more of the load and starts to heat up, its resistance further decreases and this causes it to get even hotter. This process is known as ¡°thermal runaway¡± and results (quickly) in destruction of the transistor. Emitter resistors are used to help balance the load. But with MOSFETs, their resistance INCREASES as the temperature goes up ¨C so there is an inherent self-balancing when multiple devices are used in parallel, without any need for additional balancing resistors which would increase component count and waste some power." This is nice to see, as there have been many dozen prior posts on this board (and elsewhere) about the necessity for matching these BS170 transistors in this specific use.? I'm glad I haven't wasted even more time and money in that pursuit.? I was >< this close to building a MOSFET comparator for the task.? Misinformation is murder. if you are using the U3S as the driver then get that sorted first. I'm OK on the U3Ss.? The build on mine was 100% without problems from first power-up -- it's a bone-simple kit and I have good skills.? The problems I did have (and there were many) were purely from misinformation from a surprisingly wide variety of sources. if you have limited access to test equipment... Strangely, my expenditures on test and bench equipment have exceeded those on actual radio gear by a factor of about 8:1, most notably on a new oscilloscope that I was urgently persuaded to buy and have never used once in the eight months or so that I've had it, aside from zeroing the leads and testing its self-calibration. perhaps buddy up with an elmer or find somebody at a local club I just let a membership expire on 1 January from what I believe is the largest club in my area.? They offer a free calendar year's membership to new licensees (I passed Tech and General on the same day).? I didn't find membership productive.? My thoughts on this are another post. There is a lot of info on the PA web page, build manual & App notes, but the info you need is there. It is really interesting.? The initial part on the tech background of the design is mostly over my head and not of practical use, but the actual construction and testing section is excellent. The aim is to minimise temperature change and loading to the 27MHz crystal reference and to a lesser extent the Si5351 IC during the WSPR or more demanding QRSS TX cycle The black art of Park Modes, expect to have to experiment. Everybody's unit will have a different spread of tolerances , what works for one may may make it worse on another. The long TX cycles of QRSS is the most demanding mode, if you believe you have a problem, get yourself seen on a local QRSS grabber. You can see any changes in real time(ish) and have a feel what is making things better or worse. There's only one grabber in the western US, which never picked me up in that NYD QRSS thing anyway.? However, I did monitor my own TX and it showed a very linear (if small) drift over a ~7min. TX, consistent with crystal heat-up. Many another QRSS transmission I saw on the grabber pages described the trajectory of a beanbag tossed by a toddler.? I was amazed. [But QRSS is over in the US, as is nearly every other mode in the (currently full) U3S firmware except WSPR and CW.? There's no point beaconing signals with no one listening -- and they aren't.? Even the most recent modes are essentially history.? I went from at least fifteen JT65 spots a day to one or two, and two or three JT9 spots a day to that many in a month.? Even WSPR is dropping off, it seems. Hans really needs to provide some of these graveyard modes with the solemn offices of Christian burial and free up some firmware room for FT8 and future modes that bear some interest. The object in propagation monitoring is to get the absolute maximum possible number of spots to see some patterning, and you can't do that with dud modes. I also think that a faster mode will provide more spots during marginal propagation.? The ubiquity and speed of FT8 seem to be ideal.] ?- (b) causing it to cool down.? Huh? You are thinking about, Han's solution of gluing a coin or other people have reported attaching a stick on heatsink to the crystal? The aim IS NOT to cool the crystal but to add a thermal? mass to it, to again trying to delay short term temperature changes. Now, this actually makes sense - but there are dozens of confused posts here on the subject that refer to using "heatsinks" on the crystals. ?Heatsinks are not there to provide "thermal mass" (interesting turn of phrase), but to defeat thermal mass, i.e., to cool.? Thus my confusion. A mild steel nut would be my preference over a piece of aluminium, but anything that slows the temperature change works.... I think if I were convinced that this was a problem for me, I would just wall-in the module and fill it with spray can expanding foam insulation. ?In any case, as I understand it, if you don't drift beyond +/-4, it ?doesn't make any difference anyway.? The default setting gives me as ?close to zero drift as external conditions will ever permit Once again, I'm still not understanding the quest for zero drift. a good power supply is equally required for the standard version. [...] (In particular, decoupling capacitors around the Voltage Regulators, mounted as close as you can to the device legs.? As well as hopefully decoupling RF, and general hash they prevent parasitic oscillation that affects regulators under some load conditions.) My voltage stability is absolutely rock-solid.? As to noise, I can't say, but I could probably measure it with my (unused) oscilloscope if knew how.? I'm unclear on the effects of noise on WSPR and the JT/FT modes. |
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Re: U3s first wspr
On Sun, Jan 14, 2018 at 01:09 pm, Andy G0FTD wrote:
True Blue seems to have rather quiet.I don't know what you're on about, but if you have some problem with me, why don't you deal with it like a grownup and send me private mail explaining what's wrong.? OK?? Cool. In the meantime, here's my reply I spent all afternoon reformatting offline, which was why I was so mysteriously "quiet": [edit] This is not cutting and pasting into the editor.? I'll keep trying. On Fri, Jan 12, 2018 at 05:20 pm, Alan de G1FXB wrote: On Fri, Jan 12, 2018 at 05:20 pm, Alan de G1FXB wrote: >> TrueBlue wrote: >> I'm sort of curious how 3xBS170=200mW on 40m at 9V.? That's >> about what you should get from one BS170 at ~5v on 40m. > http://qrp-labs.com/ultimate3/u3mods.html#morepower But that still doesn't explain why more voltage and more transistors, both, wouldn't increase output.? According to this, it should. > Hans spent some time writing up the theory of parallel operation. ??? "There are always minor variations between device characteristics from one transistor to the next. If these were bipolar NPN transistors, we would not be able to parallel them in this way. If one transistor takes more of the load and starts to heat up, its resistance further decreases and this causes it to get even hotter. This process is known as ¡°thermal runaway¡± and results (quickly) in destruction of the transistor. Emitter resistors are used to help balance the load. But with MOSFETs, their resistance INCREASES as the temperature goes up ¨C so there is an inherent self-balancing when multiple devices are used in parallel, without any need for additional balancing resistors which would increase component count and waste some power." This is nice to see, as there have been many dozen prior posts on this board (and elsewhere) about the necessity for matching these BS170 transistors in this specific use.? I'm glad I haven't wasted even more time and money in that pursuit.? I was >< this close to building a MOSFET comparator for the task. > if you are using the U3S as the driver then get that sorted first. I'm OK on the U3Ss.? The build on mine was 100% without problems from first power-up -- it's a bone-simple kit and I have good skills.? The problems I did have (and there were many) were purely from misinformation. > if you have limited access to test equipment... Strangely, my expenditures on test and bench equipment have exceeded those on actual radio gear by a factor of about 8:1, most notably on a new oscilloscope that I was urgently persuaded to buy and have never used once in the eight months or so that I've had it, aside from zeroing the leads and testing its self-calibration. > perhaps buddy up with an elmer or find somebody at a local club I just let a membership expire on 1 January from what I believe is the largest club in my area.? They offer a free calendar year's membership to new licensees (I passed Tech and General on the same day).? I didn't find membership productive.? My thoughts on this are another post. > There is a lot of info on the PA web page, build manual & App notes, > but the info you need is there. It is really interesting.? The initial part on the tech background of the design is mostly over my head and not of practical use, but the actual construction and testing section is excellent. > The aim is to minimise temperature change and loading to the 27MHz > crystal reference and to a lesser extent the Si5351 IC during > the WSPR or more demanding QRSS TX cycle > The black art of Park Modes, expect to have to experiment. Everybody's > unit will have a different spread of tolerances , what works for one > may may make it worse on another. > The long TX cycles of QRSS is the most demanding mode, if you believe > you have a problem, get yourself seen on a local QRSS grabber. You can > see any changes in real time(ish) and have a feel what is making > things better or worse. There's only one grabber in the western US, which never picked me up in that NYD QRSS thing anyway.? However, I did monitor my own TX and it showed a very linear (if small) drift over a ~7min. TX, consistent with crystal heat-up. Many another QRSS transmission I saw on the grabber pages described the trajectory of a beanbag tossed by a toddler.? I was amazed. [But QRSS is over in the US, as is every other mode in the (currently full) U3S firmware except WSPR and CW.? There's no point beaconing signals with no one listening -- and they aren't.? Even the most recent modes are essentially history.? I went from at least fifteen JT65 spots a day to one or two, and two or three JT9 spots a day to that many in a month.? Even WSPR is dropping off, it seems. Hans really needs to provide these graveyard modes with the solemn offices of Christian burial and free up some firmware room for FT8 and future modes that bear some interest. The object in propagation is to get the absolute maximum possible number of spots to see some patterning, and you can't do that with dud modes. I also think that a faster mode will provide more spots during marginal propagation.? The ubiquity and speed of FT8 seem to be ideal.] >> (b) causing it to cool down.? Huh? > You are thinking about, Han's solution of gluing a coin or other > people have reported attaching a stick on heatsink to the crystal? > The aim IS NOT to cool the crystal but to add a thermal? mass to it, > to again trying to delay short term temperature changes. Now, this actually makes sense - but there are dozens of misinformed posts here on the subject that refer to using heatsinks on the crystals. ?Heatsinks are not there to provide "thermal mass" (interesting turn of phrase), but to defeat thermal mass, i.e., to cool.? Thus my confusion. > A mild steel nut would be my preference over a piece of aluminium, > but anything that slows the temperature change works.... I think if I were convinced that this was a problem for me, I would just wall-in the module and fill it with spray can expanding foam insulation. >> In any case, as I understand it, if you don't drift beyond +/-4, it >> doesn't make any difference anyway.? The default setting gives me as >> close to zero drift as external conditions will ever permit Once again, I'm still not understanding the quest for zero drift. > a good power supply is equally required for the standard version. [...] > (In particular, decoupling capacitors around the Voltage Regulators, > mounted as close as you can to the device legs.? As well as hopefully > decoupling RF, and general hash they prevent parasitic oscillation > that affects regulators under some load conditions.) My voltage stability is absolutely rock-solid.? As to noise, I can't say, but I could probably measure it with my (unused) oscilloscope if knew how.? I'm unclear on the effects of noise on WSPR and the JT/FT modes. >> TrueBlue wrote: >> I'm sort of curious how 3xBS170=200mW on 40m at 9V.? That's >> about what you should get from one BS170 at ~5v on 40m. > But that still doesn't explain why more voltage and more transistors, both, wouldn't increase output.? According to this ^, it should. > Hans spent some time writing up the theory of parallel operation. ??? "There are always minor variations between device characteristics from one transistor to the next. If these were bipolar NPN transistors, we would not be able to parallel them in this way. If one transistor takes more of the load and starts to heat up, its resistance further decreases and this causes it to get even hotter. This process is known as ¡°thermal runaway¡± and results (quickly) in destruction of the transistor. Emitter resistors are used to help balance the load. But with MOSFETs, their resistance INCREASES as the temperature goes up ¨C so there is an inherent self-balancing when multiple devices are used in parallel, without any need for additional balancing resistors which would increase component count and waste some power." This is nice to see, as there have been many dozen prior posts on this board (and elsewhere) about the necessity for matching these BS170 transistors in this specific use.? I'm glad I haven't wasted even more time and money in that pursuit.? I was >< this close to building a MOSFET comparator for the task.? Misinformation is murder. > if you are using the U3S as the driver then get that sorted first. I'm OK on the U3Ss.? The build on mine was 100% without problems from first power-up -- it's a bone-simple kit and I have good skills.? The problems I did have (and there were many) were purely from misinformation from a surprising range of sources. > if you have limited access to test equipment... Strangely, my expenditures on test and bench equipment have exceeded those on actual radio gear by a factor of about 8:1, most notably on a new oscilloscope that I was urgently persuaded to buy and have never used once in the eight months or so that I've had it, aside from zeroing the leads and testing its self-calibration. > perhaps buddy up with an elmer or find somebody at a local club I just let a membership expire on 1 January from what I believe is the largest club in my area.? They offer a free calendar year's membership to new licensees (I passed Tech and General on the same day).? I didn't find membership productive.? My thoughts on this are another post. > There is a lot of info on the PA web page, build manual & App notes, > but the info you need is there. It is really interesting.? The initial part on the tech background of the design is mostly over my head and not of practical use, but the actual construction and testing section is excellent. > The aim is to minimise temperature change and loading to the 27MHz > crystal reference and to a lesser extent the Si5351 IC during > the WSPR or more demanding QRSS TX cycle > The black art of Park Modes, expect to have to experiment. Everybody's > unit will have a different spread of tolerances , what works for one > may may make it worse on another. > The long TX cycles of QRSS is the most demanding mode, if you believe > you have a problem, get yourself seen on a local QRSS grabber. You can > see any changes in real time(ish) and have a feel what is making > things better or worse. There's only one grabber in the western US, which never picked me up in that NYD QRSS thing anyway.? However, I did monitor my own TX and it showed a very linear (if small) drift over a ~7min. TX, consistent with crystal heat-up. Many another QRSS transmission I saw on the grabber pages described the trajectory of a beanbag tossed by a toddler.? I was amazed. [But QRSS is over in the US, as is every other mode in the (currently full) U3S firmware except WSPR and CW.? There's no point beaconing signals with no one listening -- and they aren't.? Even the most recent modes are essentially history.? I went from at least fifteen JT65 spots a day to one or two, and two or three JT9 spots a day to that many in a month.? Even WSPR is dropping off, it seems. Hans really needs to provide some of these graveyard modes in the U3S with the solemn offices of Christian burial and free up some firmware room for FT8 and future modes that bear some interest. The object in propagation beaconing is to get the absolute maximum possible number of spots to see some patterning, and you can't do that with dud modes.? I also think that a faster mode should provide more spots during marginal propagation.? The current ubiquity and speed of FT8 seem to be ideal.] >> (b) causing it to cool down.? Huh? > You are thinking about, Han's solution of gluing a coin or other > people have reported attaching a stick on heatsink to the crystal? > The aim IS NOT to cool the crystal but to add a thermal? mass to it, > to again trying to delay short term temperature changes. Now, this actually makes sense - but there are dozens of misinformed posts here on the subject that refer to using heatsinks on the crystals. ?Heatsinks are not there to provide "thermal mass" (interesting turn of phrase), but to defeat thermal mass, i.e., to cool.? Thus my confusion. Thanks for clearing that up. > A mild steel nut would be my preference over a piece of aluminium, > but anything that slows the temperature change works.... I think if I were convinced that this was a problem for me, I would just wall-in the module and fill it with spray can expanding foam insulation. I doubt one could improve on that. >> In any case, as I understand it, if you don't drift beyond +/-4, it >> doesn't make any difference anyway.? The default setting gives me as >> close to zero drift as external conditions will ever permit Once again, I'm still not understanding the quest for zero drift, at least with WSPR.? > a good power supply is equally required for the standard version. [...] > (In particular, decoupling capacitors around the Voltage Regulators, > mounted as close as you can to the device legs.? As well as hopefully > decoupling RF, and general hash they prevent parasitic oscillation > that affects regulators under some load conditions.) My voltage stability is absolutely rock-solid.? As to noise, I can't say, but I could probably measure it with my (unused) oscilloscope if knew how.? I'm unclear on the effects of noise on WSPR and the JT/FT modes. |
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Re: U3s first wspr
On Sun, Jan 14, 2018 at 01:09 pm, Andy G0FTD wrote:
True Blue seems to have rather quiet.I don't know what you're on about, but if you have some problem with me, why don't you deal with it like a grownup and send me private mail explaining what's wrong.? OK?? Cool. In the meantime, here's my reply I spent all afternoon reformatting offline, which was why I was so mysteriously "quiet": On Fri, Jan 12, 2018 at 05:20 pm, Alan de G1FXB wrote: >> TrueBlue wrote: >> I'm sort of curious how 3xBS170=200mW on 40m at 9V.? That's >> about what you should get from one BS170 at ~5v on 40m. > But that still doesn't explain why more voltage and more transistors, both, wouldn't increase output.? According to this ^, it should. > Hans spent some time writing up the theory of parallel operation. ??? "There are always minor variations between device characteristics from one transistor to the next. If these were bipolar NPN transistors, we would not be able to parallel them in this way. If one transistor takes more of the load and starts to heat up, its resistance further decreases and this causes it to get even hotter. This process is known as ¡°thermal runaway¡± and results (quickly) in destruction of the transistor. Emitter resistors are used to help balance the load. But with MOSFETs, their resistance INCREASES as the temperature goes up ¨C so there is an inherent self-balancing when multiple devices are used in parallel, without any need for additional balancing resistors which would increase component count and waste some power." This is nice to see, as there have been many dozen prior posts on this board (and elsewhere) about the necessity for matching these BS170 transistors in this specific use.? I'm glad I haven't wasted even more time and money in that pursuit.? I was >< this close to building a MOSFET comparator for the task.? Misinformation is murder. > if you are using the U3S as the driver then get that sorted first. I'm OK on the U3Ss.? The build on mine was 100% without problems from first power-up -- it's a bone-simple kit and I have good skills.? The problems I did have (and there were many) were purely from misinformation from a surprising range of sources. > if you have limited access to test equipment... Strangely, my expenditures on test and bench equipment have exceeded those on actual radio gear by a factor of about 8:1, most notably on a new oscilloscope that I was urgently persuaded to buy and have never used once in the eight months or so that I've had it, aside from zeroing the leads and testing its self-calibration. > perhaps buddy up with an elmer or find somebody at a local club I just let a membership expire on 1 January from what I believe is the largest club in my area.? They offer a free calendar year's membership to new licensees (I passed Tech and General on the same day).? I didn't find membership productive.? My thoughts on this are another post. > There is a lot of info on the PA web page, build manual & App notes, > but the info you need is there. It is really interesting.? The initial part on the tech background of the design is mostly over my head and not of practical use, but the actual construction and testing section is excellent. > The aim is to minimise temperature change and loading to the 27MHz > crystal reference and to a lesser extent the Si5351 IC during > the WSPR or more demanding QRSS TX cycle > The black art of Park Modes, expect to have to experiment. Everybody's > unit will have a different spread of tolerances , what works for one > may may make it worse on another. > The long TX cycles of QRSS is the most demanding mode, if you believe > you have a problem, get yourself seen on a local QRSS grabber. You can > see any changes in real time(ish) and have a feel what is making > things better or worse. There's only one grabber in the western US, which never picked me up in that NYD QRSS thing anyway.? However, I did monitor my own TX and it showed a very linear (if small) drift over a ~7min. TX, consistent with crystal heat-up. Many another QRSS transmission I saw on the grabber pages described the trajectory of a beanbag tossed by a toddler.? I was amazed. [But QRSS is over in the US, as is every other mode in the (currently full) U3S firmware except WSPR and CW.? There's no point beaconing signals with no one listening -- and they aren't.? Even the most recent modes are essentially history.? I went from at least fifteen JT65 spots a day to one or two, and two or three JT9 spots a day to that many in a month.? Even WSPR is dropping off, it seems. Hans really needs to provide some of these graveyard modes in the U3S with the solemn offices of Christian burial and free up some firmware room for FT8 and future modes that bear some interest. The object in propagation beaconing is to get the absolute maximum possible number of spots to see some patterning, and you can't do that with dud modes.? I also think that a faster mode should provide more spots during marginal propagation.? The current ubiquity and speed of FT8 seem to be ideal.] >> (b) causing it to cool down.? Huh? > You are thinking about, Han's solution of gluing a coin or other > people have reported attaching a stick on heatsink to the crystal? > The aim IS NOT to cool the crystal but to add a thermal? mass to it, > to again trying to delay short term temperature changes. Now, this actually makes sense - but there are dozens of misinformed posts here on the subject that refer to using heatsinks on the crystals. ?Heatsinks are not there to provide "thermal mass" (interesting turn of phrase), but to defeat thermal mass, i.e., to cool.? Thus my confusion. Thanks for clearing that up. > A mild steel nut would be my preference over a piece of aluminium, > but anything that slows the temperature change works.... I think if I were convinced that this was a problem for me, I would just wall-in the module and fill it with spray can expanding foam insulation. I doubt one could improve on that. >> In any case, as I understand it, if you don't drift beyond +/-4, it >> doesn't make any difference anyway.? The default setting gives me as >> close to zero drift as external conditions will ever permit Once again, I'm still not understanding the quest for zero drift, at least with WSPR.? > a good power supply is equally required for the standard version. [...] > (In particular, decoupling capacitors around the Voltage Regulators, > mounted as close as you can to the device legs.? As well as hopefully > decoupling RF, and general hash they prevent parasitic oscillation > that affects regulators under some load conditions.) My voltage stability is absolutely rock-solid.? As to noise, I can't say, but I could probably measure it with my (unused) oscilloscope if knew how.? I'm unclear on the effects of noise on WSPR and the JT/FT modes. |
TrueBlue
Bernd