Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 20:55, David Bengtson wrote: > > Might be worth writing a Python version for GNU Radio - it would be > > pretty simple I think. > > How about going old school and using a calculator? No memory footprint > on the computer at all. Yeah, funny thing about computers, they were invented as labour saving devices :) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpRs7dihIKKT.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
Brian Padalino wrote: I am really surprised on how you guys are so anti-spreadsheets. A lot of the RF engineers where I work like using them when designing their receive and transmit chains for calculating tolerances and all sorts of noise figures. One even modeled the front end amplifier gain stages for which DAC values should be used at each input power over our 75 dB of gain so when I wrote the FPGA module to actually do the AGC we could compare my simulation results with their ideal gain for any given input. Then again, I guess people stick with the tools they know - though I do implore you to all take a second look at the mighty spreadsheet. They really are more powerful than what you are giving them credit for. I'm in the process of writing a PLL analysis tool in Excel, located at http://www.keystoneradio.com/PllDesign.html, probably at the high end of things you can do with Excel. The other thing to think about is that spreadsheets are a very common tool, while tkl/python etc require installation. In a corporate environment, you are pretty guaranteed to have Excel, but the other stuff may be more difficult to get hold of. Dave ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
Daniel O'Connor wrote: On Friday 29 September 2006 09:21, John Ackermann N8UR wrote: I have to say that I like dBs, too. All you have to do is remember two things: 3dB doubles the power, and 10dB is 10 times the power, and from that you can SWAG just about anything. A guy at work wrote a handy program in Tcl/Tk for converting power between various units (dBm, mW, Volts & Pk-Pk Volts). Might be worth writing a Python version for GNU Radio - it would be pretty simple I think. How about going old school and using a calculator? No memory footprint on the computer at all. Dave ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 12:33, Brian Padalino wrote: > I am really surprised on how you guys are so anti-spreadsheets. > > A lot of the RF engineers where I work like using them when designing > their receive and transmit chains for calculating tolerances and all > sorts of noise figures. > > One even modeled the front end amplifier gain stages for which DAC > values should be used at each input power over our 75 dB of gain so > when I wrote the FPGA module to actually do the AGC we could compare > my simulation results with their ideal gain for any given input. This sort of thing makes perfect sense for a spreadsheet. Our RF engineer uses them for working out receiver gain distribution and other things. We use the Tcl/Tk program for doing stuff like calculating output power of a transmitter as you look at the scope on its sniff port.. much faster than loading a spreadsheet :) Languages like Tcl are *very* easy to program even for novice coders (like our RF engineer :) and are usually very portable as well. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpCw4TYz1pjk.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
I am really surprised on how you guys are so anti-spreadsheets. A lot of the RF engineers where I work like using them when designing their receive and transmit chains for calculating tolerances and all sorts of noise figures. One even modeled the front end amplifier gain stages for which DAC values should be used at each input power over our 75 dB of gain so when I wrote the FPGA module to actually do the AGC we could compare my simulation results with their ideal gain for any given input. Then again, I guess people stick with the tools they know - though I do implore you to all take a second look at the mighty spreadsheet. They really are more powerful than what you are giving them credit for. On 9/28/06, Daniel O'Connor <[EMAIL PROTECTED]> wrote: On Friday 29 September 2006 11:49, Berndt Josef Wulf wrote: > BTW: I do these calculations in my head - pretty much primary school stuff > really. Yeah, depends what level of accuracy you need though :) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 12:03, Daniel O'Connor wrote: > On Friday 29 September 2006 11:49, Berndt Josef Wulf wrote: > > BTW: I do these calculations in my head - pretty much primary school > > stuff really. > > Yeah, depends what level of accuracy you need though :) How accurate do you need it... :-) cheerio Berndt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 11:49, Berndt Josef Wulf wrote: > BTW: I do these calculations in my head - pretty much primary school stuff > really. Yeah, depends what level of accuracy you need though :) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpx9KYUHV40M.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 11:33, Brian Padalino wrote: > You could open Google Spreadsheets in the web browser you've probably > already got open. Not only that, but you can share it with your > buddies for collaborative editing so everyone can use it! Or write it in javascript.. > Or you could just write a bc script to to handle it. That uses much > less memory, I am sure. Lacks flexibility. > Or we could ask Google to build it into their calculator function so > you can just type "200 dB in mW" and it would do the conversion for > you! Kind of slow. > I wasn't trying to be a jerk, but I have noticed that spreadsheets are > much better at converting data to a visual format as well as extending > a dataset you might be building and doing some visual interpretations. > There's always more than one way to skin a cat, as GNURadio is all > about. Spreadsheets take too long to load, we already have tcl/tk stuff running because our radar uses it. Presumably a Python version would be good for GNURadio since you'd already be using it :) -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpBPo9e8s1F3.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
I guess this is the difference big between RF engineers and academics - applied versus theory. Spreadsheets can help in doing conversion/calculations but doesn't stop people from using these values out of context as for this you need to know what you're doing. BTW: I do these calculations in my head - pretty much primary school stuff really. cheerio Berndt On Friday 29 September 2006 11:33, Brian Padalino wrote: > You could open Google Spreadsheets in the web browser you've probably > already got open. Not only that, but you can share it with your > buddies for collaborative editing so everyone can use it! > > Or you could just write a bc script to to handle it. That uses much > less memory, I am sure. > > Or we could ask Google to build it into their calculator function so > you can just type "200 dB in mW" and it would do the conversion for > you! > > I wasn't trying to be a jerk, but I have noticed that spreadsheets are > much better at converting data to a visual format as well as extending > a dataset you might be building and doing some visual interpretations. > There's always more than one way to skin a cat, as GNURadio is all > about. > > On 9/28/06, Daniel O'Connor <[EMAIL PROTECTED]> wrote: > > On Friday 29 September 2006 10:13, Brian Padalino wrote: > > > A spreadsheet could work just the same without all the Tcl/Tk > > > silliness or input verification problems. > > > > Yeah, a spreadsheet, so lightweight compared to a memory hungry Tcl/Tk > > application. > > > > 12623 radar 1 1030 11972K 6068K select 0:00 3.97% wish8.4 > > 12643 darius6 200 120M 72048K kserel 0:07 0.00% > > soffice.bin > > > > *cough* > > > > Not sure what you mean about input verification. > > > > -- > > Daniel O'Connor software and network engineer > > for Genesis Software - http://www.gsoft.com.au > > "The nice thing about standards is that there > > are so many of them to choose from." > > -- Andrew Tanenbaum > > GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
You could open Google Spreadsheets in the web browser you've probably already got open. Not only that, but you can share it with your buddies for collaborative editing so everyone can use it! Or you could just write a bc script to to handle it. That uses much less memory, I am sure. Or we could ask Google to build it into their calculator function so you can just type "200 dB in mW" and it would do the conversion for you! I wasn't trying to be a jerk, but I have noticed that spreadsheets are much better at converting data to a visual format as well as extending a dataset you might be building and doing some visual interpretations. There's always more than one way to skin a cat, as GNURadio is all about. On 9/28/06, Daniel O'Connor <[EMAIL PROTECTED]> wrote: On Friday 29 September 2006 10:13, Brian Padalino wrote: > A spreadsheet could work just the same without all the Tcl/Tk > silliness or input verification problems. Yeah, a spreadsheet, so lightweight compared to a memory hungry Tcl/Tk application. 12623 radar 1 1030 11972K 6068K select 0:00 3.97% wish8.4 12643 darius6 200 120M 72048K kserel 0:07 0.00% soffice.bin *cough* Not sure what you mean about input verification. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 10:13, Brian Padalino wrote: > A spreadsheet could work just the same without all the Tcl/Tk > silliness or input verification problems. Yeah, a spreadsheet, so lightweight compared to a memory hungry Tcl/Tk application. 12623 radar 1 1030 11972K 6068K select 0:00 3.97% wish8.4 12643 darius6 200 120M 72048K kserel 0:07 0.00% soffice.bin *cough* Not sure what you mean about input verification. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpbf93Fm4plu.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
A spreadsheet could work just the same without all the Tcl/Tk silliness or input verification problems. On 9/28/06, Daniel O'Connor <[EMAIL PROTECTED]> wrote: On Friday 29 September 2006 09:21, John Ackermann N8UR wrote: > I have to say that I like dBs, too. All you have to do is remember two > things: 3dB doubles the power, and 10dB is 10 times the power, and from > that you can SWAG just about anything. A guy at work wrote a handy program in Tcl/Tk for converting power between various units (dBm, mW, Volts & Pk-Pk Volts). Might be worth writing a Python version for GNU Radio - it would be pretty simple I think. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
On Friday 29 September 2006 09:21, John Ackermann N8UR wrote: > I have to say that I like dBs, too. All you have to do is remember two > things: 3dB doubles the power, and 10dB is 10 times the power, and from > that you can SWAG just about anything. A guy at work wrote a handy program in Tcl/Tk for converting power between various units (dBm, mW, Volts & Pk-Pk Volts). Might be worth writing a Python version for GNU Radio - it would be pretty simple I think. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpttPpYS8Apq.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
I have to say that I like dBs, too. All you have to do is remember two things: 3dB doubles the power, and 10dB is 10 times the power, and from that you can SWAG just about anything. John Berndt Josef Wulf said the following on 09/28/2006 07:26 PM: > It don't see how this makes the calculation of RF power any easier, to the > contrary it confuses the issue. > > cheerio Berndt > > On Thursday 28 September 2006 17:50, John Gilmore wrote: >>> transmit power converted to dBm (1 dBm == 1 mW) minus the attenuator >>> loss = output power in dBm. >>> >>> E.g. >>> 100 mW -> 20dBm >>> 20dBm - 15 db att = 5 dBm >>> 5 dBm -> 3.2 mW >> Actually, I think 0 dBm = 1 mW. >> >> dB's are a royal pain in the butt. They eluded me for years because >> they required a lot of rote memorization and made no sense. For those >> of us not pickled in radio-speak from an early age, but who know basic >> algebra, there's a simple way to deal. Ignore deciBels. Use Bels. >> >> Bels are easy and obvious. They're a straight logarithmic scale in Base >> 10. 100 mW is 2 Bm. 10 mW is 1 Bm. 1 mW is 0 Bm. 0.1 mW is -1 Bm. >> >> DeciBels are just tenths of a bel. So if you shift the decimal point >> one place, you're suddenly calculating in an easy to use notation. >> >> Here's the above calculation in Bels: >>> 100 mW -> 2 Bm >>> 2 Bm - 1.5 B att = 0.5 Bm >>> 0.5 Bm -> 10 to the 0.5 power -> the square root of 10 -> about 3.2 mW >> See, now you not only know the answer, but you know WHY "5dBm" is 3.2 mW. >> >> Why the EE universe settled on doing everything in tenths of a >> logarithmic unit is way beyond me. It's as if every carpenter figured >> every length in deciInches or decimeters, even if inches, kilometers >> or meters would be the more straightforward unit. How often do you >> calculate in decivolts, deciwatts, or decimeters per second per >> second? >> >> The rumor is that decibels were invented because somebody at Bell Labs >> couldn't cope with decimal points or negative numbers, in the days when >> equipment wasn't capable of dealing with large orders of magnitude >> (e.g. the painful-to-someone 0.3 Bel became the friendly-to-someone 3 >> deciBel). Of course, now that people regularly see 5 to 10 orders of >> magnitude (5 to 10 Bels) (50 to 100 deciBels) (factors of 1 to 10 >> billion) in ratios, such as in radar, digital signal processing, or >> fiber optics, the "deci" has just become a hindrance. >> >> You can do your part to clear up this idiocy by using Bels in most >> places where the lemmings use deciBels. You may actually get them to >> think (briefly). >> >> John >> >> PS: Don't even get me started about why dBm's aren't referenced to >> watts rather than milliwatts! Since a "milli" is 1/1000th and that's >> just 3 orders of magnitude, referencing to ordinary watts would merely >> involve subtracting 3 or 30 from the number, e.g. 40 dBm = 4 Bm = 1 BW >> = 10 dBW. It reminds me of how we're still calculating speeds in >> 5280-foot units per 3600-second units rather than in some sane system >> using basic decimal units. Actually using BW notation in your >> thinking and writing may overload lemming brains, though. >> >> >> ___ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
It don't see how this makes the calculation of RF power any easier, to the contrary it confuses the issue. cheerio Berndt On Thursday 28 September 2006 17:50, John Gilmore wrote: > > transmit power converted to dBm (1 dBm == 1 mW) minus the attenuator > > loss = output power in dBm. > > > > E.g. > > 100 mW -> 20dBm > > 20dBm - 15 db att = 5 dBm > > 5 dBm -> 3.2 mW > > Actually, I think 0 dBm = 1 mW. > > dB's are a royal pain in the butt. They eluded me for years because > they required a lot of rote memorization and made no sense. For those > of us not pickled in radio-speak from an early age, but who know basic > algebra, there's a simple way to deal. Ignore deciBels. Use Bels. > > Bels are easy and obvious. They're a straight logarithmic scale in Base > 10. 100 mW is 2 Bm. 10 mW is 1 Bm. 1 mW is 0 Bm. 0.1 mW is -1 Bm. > > DeciBels are just tenths of a bel. So if you shift the decimal point > one place, you're suddenly calculating in an easy to use notation. > > Here's the above calculation in Bels: > > 100 mW -> 2 Bm > > 2 Bm - 1.5 B att = 0.5 Bm > > 0.5 Bm -> 10 to the 0.5 power -> the square root of 10 -> about 3.2 mW > > See, now you not only know the answer, but you know WHY "5dBm" is 3.2 mW. > > Why the EE universe settled on doing everything in tenths of a > logarithmic unit is way beyond me. It's as if every carpenter figured > every length in deciInches or decimeters, even if inches, kilometers > or meters would be the more straightforward unit. How often do you > calculate in decivolts, deciwatts, or decimeters per second per > second? > > The rumor is that decibels were invented because somebody at Bell Labs > couldn't cope with decimal points or negative numbers, in the days when > equipment wasn't capable of dealing with large orders of magnitude > (e.g. the painful-to-someone 0.3 Bel became the friendly-to-someone 3 > deciBel). Of course, now that people regularly see 5 to 10 orders of > magnitude (5 to 10 Bels) (50 to 100 deciBels) (factors of 1 to 10 > billion) in ratios, such as in radar, digital signal processing, or > fiber optics, the "deci" has just become a hindrance. > > You can do your part to clear up this idiocy by using Bels in most > places where the lemmings use deciBels. You may actually get them to > think (briefly). > > John > > PS: Don't even get me started about why dBm's aren't referenced to > watts rather than milliwatts! Since a "milli" is 1/1000th and that's > just 3 orders of magnitude, referencing to ordinary watts would merely > involve subtracting 3 or 30 from the number, e.g. 40 dBm = 4 Bm = 1 BW > = 10 dBW. It reminds me of how we're still calculating speeds in > 5280-foot units per 3600-second units rather than in some sane system > using basic decimal units. Actually using BW notation in your > thinking and writing may overload lemming brains, though. > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] to prevent mental damages, avoid dB's.
> transmit power converted to dBm (1 dBm == 1 mW) minus the attenuator > loss = output power in dBm. > > E.g. > 100 mW -> 20dBm > 20dBm - 15 db att = 5 dBm > 5 dBm -> 3.2 mW Actually, I think 0 dBm = 1 mW. dB's are a royal pain in the butt. They eluded me for years because they required a lot of rote memorization and made no sense. For those of us not pickled in radio-speak from an early age, but who know basic algebra, there's a simple way to deal. Ignore deciBels. Use Bels. Bels are easy and obvious. They're a straight logarithmic scale in Base 10. 100 mW is 2 Bm. 10 mW is 1 Bm. 1 mW is 0 Bm. 0.1 mW is -1 Bm. DeciBels are just tenths of a bel. So if you shift the decimal point one place, you're suddenly calculating in an easy to use notation. Here's the above calculation in Bels: > 100 mW -> 2 Bm > 2 Bm - 1.5 B att = 0.5 Bm > 0.5 Bm -> 10 to the 0.5 power -> the square root of 10 -> about 3.2 mW See, now you not only know the answer, but you know WHY "5dBm" is 3.2 mW. Why the EE universe settled on doing everything in tenths of a logarithmic unit is way beyond me. It's as if every carpenter figured every length in deciInches or decimeters, even if inches, kilometers or meters would be the more straightforward unit. How often do you calculate in decivolts, deciwatts, or decimeters per second per second? The rumor is that decibels were invented because somebody at Bell Labs couldn't cope with decimal points or negative numbers, in the days when equipment wasn't capable of dealing with large orders of magnitude (e.g. the painful-to-someone 0.3 Bel became the friendly-to-someone 3 deciBel). Of course, now that people regularly see 5 to 10 orders of magnitude (5 to 10 Bels) (50 to 100 deciBels) (factors of 1 to 10 billion) in ratios, such as in radar, digital signal processing, or fiber optics, the "deci" has just become a hindrance. You can do your part to clear up this idiocy by using Bels in most places where the lemmings use deciBels. You may actually get them to think (briefly). John PS: Don't even get me started about why dBm's aren't referenced to watts rather than milliwatts! Since a "milli" is 1/1000th and that's just 3 orders of magnitude, referencing to ordinary watts would merely involve subtracting 3 or 30 from the number, e.g. 40 dBm = 4 Bm = 1 BW = 10 dBW. It reminds me of how we're still calculating speeds in 5280-foot units per 3600-second units rather than in some sane system using basic decimal units. Actually using BW notation in your thinking and writing may overload lemming brains, though. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
