On Tue, 22 Nov 2011 15:47:02 -0600, Tim <tim@seemywebsite.please> wrote:>On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: > >> On Tue, 22 Nov 2011 00:56:03 -0600, Tim <tim@seemywebsite.please> wrote: >> >>>On Mon, 21 Nov 2011 22:36:33 -0600, Vladimir Vassilevsky wrote: >>> >>>> Tim Wescott wrote: >>>> >>>>> Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 >>>>> signal generator? >>>>> >>>>> A customer is testing a PLL that I designed. The PLL is designed to >>>>> go into the far sub-Hz bandwidths, and they're having trouble getting >>>>> it to lock onto the 15kHz signal from a Wavetek 273. I've got it >>>>> running off of a crystal oscillator divided down and made into a sine >>>>> wave, and it's perking along quite happily at a bandwidth of 1/50th >>>>> Hz. They can't run it at a bandwidth below about 5Hz. >>>> >>>> What is your PLL acquisition bandwidth? >>>> >>>>> All I can find for that signal generator are places selling manuals, >>>>> and a picture of the front panel. It has a digital readout and >>>>> appears to be synthesized -- yet it's actual performance doesn't seem >>>>> to jibe with the performance my customer is seeing. >>>> >>>> The 1e-5 is too much of accuracy expectation for the off-the-shelf MCU >>>> grade crystal; not mentionning 1e-6. You can reliably count on 1e-4. >>>> >>>>> So I'm wondering if its broken, or if it's just a multivibrator >>>>> oscillator behind a dolled-up digital panel, or what. >>>> >>>> Add a discriminator to your PLL or use a frequency-phase detector to >>>> assist the initial pull-in. >>> >>>I'm not talking about acquisition, that works just fine (it starts with >>>a discriminator, then switches to a wide-open PI filter once the phase >>>stops hopping around, then when the phase settles in it stops down the >>>gain to whatever the preset value is). >>> >>>The problem is holding lock -- they can't get it to stay locked unless >>>the bandwidth is above one or two Hz, while mine stays locked just fine >>>on my 12.5kHz crystal derived signal. Since this is very symptomatic of >>>the signal generator not being in good shape, I'm thinking in that >>>direction. >>> >>>I suppose they could have issues with their processor crystal -- but >>>it'd have to be exceedingly sick. >> >> --- >> Why not lend them your generator and let then check their Wavetek >> against it? > >Not a bad idea, except that it's cobbled together on a protoboard, and >they're several hundred miles away.I once worked for a guy who built marine automation stuff on those white plastic proto horrors, RTVd them into aluminum boxes, and sold them. Well, I didn't work for him for very long. John
Wavetek 273
Started by ●November 21, 2011
Reply by ●November 23, 20112011-11-23
Reply by ●November 23, 20112011-11-23
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Tue, 22 Nov 2011 15:47:02 -0600, Tim <tim@seemywebsite.please> >wrote: > >>On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: >> >>> --- >>> Why not lend them your generator and let then check their Wavetek >>> against it? >> >>Not a bad idea, except that it's cobbled together on a protoboard, and >>they're several hundred miles away.Tim: I guess you have to. You may find other problems as well. Maybe its just interference from a GSM antenna.>I once worked for a guy who built marine automation stuff on those >white plastic proto horrors, RTVd them into aluminum boxes, and sold >them. Well, I didn't work for him for very long.You are kidding right? -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●November 23, 20112011-11-23
On Tue, 22 Nov 2011 15:47:02 -0600, Tim <tim@seemywebsite.please> wrote:>On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: > >> On Tue, 22 Nov 2011 00:56:03 -0600, Tim <tim@seemywebsite.please> wrote: >> >>>On Mon, 21 Nov 2011 22:36:33 -0600, Vladimir Vassilevsky wrote: >>> >>>> Tim Wescott wrote: >>>> >>>>> Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 >>>>> signal generator? >>>>> >>>>> A customer is testing a PLL that I designed. The PLL is designed to >>>>> go into the far sub-Hz bandwidths, and they're having trouble getting >>>>> it to lock onto the 15kHz signal from a Wavetek 273. I've got it >>>>> running off of a crystal oscillator divided down and made into a sine >>>>> wave, and it's perking along quite happily at a bandwidth of 1/50th >>>>> Hz. They can't run it at a bandwidth below about 5Hz. >>>> >>>> What is your PLL acquisition bandwidth? >>>> >>>>> All I can find for that signal generator are places selling manuals, >>>>> and a picture of the front panel. It has a digital readout and >>>>> appears to be synthesized -- yet it's actual performance doesn't seem >>>>> to jibe with the performance my customer is seeing. >>>> >>>> The 1e-5 is too much of accuracy expectation for the off-the-shelf MCU >>>> grade crystal; not mentionning 1e-6. You can reliably count on 1e-4. >>>> >>>>> So I'm wondering if its broken, or if it's just a multivibrator >>>>> oscillator behind a dolled-up digital panel, or what. >>>> >>>> Add a discriminator to your PLL or use a frequency-phase detector to >>>> assist the initial pull-in. >>> >>>I'm not talking about acquisition, that works just fine (it starts with >>>a discriminator, then switches to a wide-open PI filter once the phase >>>stops hopping around, then when the phase settles in it stops down the >>>gain to whatever the preset value is). >>> >>>The problem is holding lock -- they can't get it to stay locked unless >>>the bandwidth is above one or two Hz, while mine stays locked just fine >>>on my 12.5kHz crystal derived signal. Since this is very symptomatic of >>>the signal generator not being in good shape, I'm thinking in that >>>direction. >>> >>>I suppose they could have issues with their processor crystal -- but >>>it'd have to be exceedingly sick. >> >> --- >> Why not lend them your generator and let then check their Wavetek >> against it? > >Not a bad idea, except that it's cobbled together on a protoboard, and >they're several hundred miles away.--- If I had a substantial enough PO just waiting to be issued, pending successful completion of a test, I'd either: 1. Drive the test rig up there and use it to show up the Wavetek's deficiencies, 2. Clean up my test rig, ruggedize it and send it to them, or 3. Rent a suitable synthesizer and have it drop-shipped to them. -- JF
Reply by ●November 23, 20112011-11-23
On Wed, 23 Nov 2011 02:04:19 +0100, Fred Bartoli <" "> wrote:>Tim a �crit : >> On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: >> >>> On Tue, 22 Nov 2011 00:56:03 -0600, Tim <tim@seemywebsite.please> wrote: >>> >>>> On Mon, 21 Nov 2011 22:36:33 -0600, Vladimir Vassilevsky wrote: >>>> >>>>> Tim Wescott wrote: >>>>> >>>>>> Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 >>>>>> signal generator? >>>>>> >>>>>> A customer is testing a PLL that I designed. The PLL is designed to >>>>>> go into the far sub-Hz bandwidths, and they're having trouble getting >>>>>> it to lock onto the 15kHz signal from a Wavetek 273. I've got it >>>>>> running off of a crystal oscillator divided down and made into a sine >>>>>> wave, and it's perking along quite happily at a bandwidth of 1/50th >>>>>> Hz. They can't run it at a bandwidth below about 5Hz. >>>>> What is your PLL acquisition bandwidth? >>>>> >>>>>> All I can find for that signal generator are places selling manuals, >>>>>> and a picture of the front panel. It has a digital readout and >>>>>> appears to be synthesized -- yet it's actual performance doesn't seem >>>>>> to jibe with the performance my customer is seeing. >>>>> The 1e-5 is too much of accuracy expectation for the off-the-shelf MCU >>>>> grade crystal; not mentionning 1e-6. You can reliably count on 1e-4. >>>>> >>>>>> So I'm wondering if its broken, or if it's just a multivibrator >>>>>> oscillator behind a dolled-up digital panel, or what. >>>>> Add a discriminator to your PLL or use a frequency-phase detector to >>>>> assist the initial pull-in. >>>> I'm not talking about acquisition, that works just fine (it starts with >>>> a discriminator, then switches to a wide-open PI filter once the phase >>>> stops hopping around, then when the phase settles in it stops down the >>>> gain to whatever the preset value is). >>>> >>>> The problem is holding lock -- they can't get it to stay locked unless >>>> the bandwidth is above one or two Hz, while mine stays locked just fine >>>> on my 12.5kHz crystal derived signal. Since this is very symptomatic of >>>> the signal generator not being in good shape, I'm thinking in that >>>> direction. >>>> >>>> I suppose they could have issues with their processor crystal -- but >>>> it'd have to be exceedingly sick. >>> --- >>> Why not lend them your generator and let then check their Wavetek >>> against it? >> >> Not a bad idea, except that it's cobbled together on a protoboard, and >> they're several hundred miles away. >> > >Bad idea indeed! >You'd have a lot of jitter on the parts' arrival time...--- What do you mean? -- JF
Reply by ●November 24, 20112011-11-24
John Fields a �crit :> On Wed, 23 Nov 2011 02:04:19 +0100, Fred Bartoli <" "> wrote: > >> Tim a �crit : >>> On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: >>> >>>> On Tue, 22 Nov 2011 00:56:03 -0600, Tim <tim@seemywebsite.please> wrote: >>>> >>>>> On Mon, 21 Nov 2011 22:36:33 -0600, Vladimir Vassilevsky wrote: >>>>> >>>>>> Tim Wescott wrote: >>>>>> >>>>>>> Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 >>>>>>> signal generator? >>>>>>> >>>>>>> A customer is testing a PLL that I designed. The PLL is designed to >>>>>>> go into the far sub-Hz bandwidths, and they're having trouble getting >>>>>>> it to lock onto the 15kHz signal from a Wavetek 273. I've got it >>>>>>> running off of a crystal oscillator divided down and made into a sine >>>>>>> wave, and it's perking along quite happily at a bandwidth of 1/50th >>>>>>> Hz. They can't run it at a bandwidth below about 5Hz. >>>>>> What is your PLL acquisition bandwidth? >>>>>> >>>>>>> All I can find for that signal generator are places selling manuals, >>>>>>> and a picture of the front panel. It has a digital readout and >>>>>>> appears to be synthesized -- yet it's actual performance doesn't seem >>>>>>> to jibe with the performance my customer is seeing. >>>>>> The 1e-5 is too much of accuracy expectation for the off-the-shelf MCU >>>>>> grade crystal; not mentionning 1e-6. You can reliably count on 1e-4. >>>>>> >>>>>>> So I'm wondering if its broken, or if it's just a multivibrator >>>>>>> oscillator behind a dolled-up digital panel, or what. >>>>>> Add a discriminator to your PLL or use a frequency-phase detector to >>>>>> assist the initial pull-in. >>>>> I'm not talking about acquisition, that works just fine (it starts with >>>>> a discriminator, then switches to a wide-open PI filter once the phase >>>>> stops hopping around, then when the phase settles in it stops down the >>>>> gain to whatever the preset value is). >>>>> >>>>> The problem is holding lock -- they can't get it to stay locked unless >>>>> the bandwidth is above one or two Hz, while mine stays locked just fine >>>>> on my 12.5kHz crystal derived signal. Since this is very symptomatic of >>>>> the signal generator not being in good shape, I'm thinking in that >>>>> direction. >>>>> >>>>> I suppose they could have issues with their processor crystal -- but >>>>> it'd have to be exceedingly sick. >>>> --- >>>> Why not lend them your generator and let then check their Wavetek >>>> against it? >>> Not a bad idea, except that it's cobbled together on a protoboard, and >>> they're several hundred miles away. >>> >> Bad idea indeed! >> You'd have a lot of jitter on the parts' arrival time... > > --- > What do you mean? >Try wiring something on those white protoboards then send this 1000 miles away through UPS and see if/when parts arrive... You might expect some group delay distortion :-) IOW some jitter on parts arrival time -- Thanks, Fred.
Reply by ●November 24, 20112011-11-24
On Thu, 24 Nov 2011 09:22:04 +0100, Fred Bartoli <" "> wrote:>John Fields a �crit : >> On Wed, 23 Nov 2011 02:04:19 +0100, Fred Bartoli <" "> wrote: >> >>> Tim a �crit : >>>> On Tue, 22 Nov 2011 01:55:17 -0600, John Fields wrote: >>>> >>>>> On Tue, 22 Nov 2011 00:56:03 -0600, Tim <tim@seemywebsite.please> wrote: >>>>> >>>>>> On Mon, 21 Nov 2011 22:36:33 -0600, Vladimir Vassilevsky wrote: >>>>>> >>>>>>> Tim Wescott wrote: >>>>>>> >>>>>>>> Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 >>>>>>>> signal generator? >>>>>>>> >>>>>>>> A customer is testing a PLL that I designed. The PLL is designed to >>>>>>>> go into the far sub-Hz bandwidths, and they're having trouble getting >>>>>>>> it to lock onto the 15kHz signal from a Wavetek 273. I've got it >>>>>>>> running off of a crystal oscillator divided down and made into a sine >>>>>>>> wave, and it's perking along quite happily at a bandwidth of 1/50th >>>>>>>> Hz. They can't run it at a bandwidth below about 5Hz. >>>>>>> What is your PLL acquisition bandwidth? >>>>>>> >>>>>>>> All I can find for that signal generator are places selling manuals, >>>>>>>> and a picture of the front panel. It has a digital readout and >>>>>>>> appears to be synthesized -- yet it's actual performance doesn't seem >>>>>>>> to jibe with the performance my customer is seeing. >>>>>>> The 1e-5 is too much of accuracy expectation for the off-the-shelf MCU >>>>>>> grade crystal; not mentionning 1e-6. You can reliably count on 1e-4. >>>>>>> >>>>>>>> So I'm wondering if its broken, or if it's just a multivibrator >>>>>>>> oscillator behind a dolled-up digital panel, or what. >>>>>>> Add a discriminator to your PLL or use a frequency-phase detector to >>>>>>> assist the initial pull-in. >>>>>> I'm not talking about acquisition, that works just fine (it starts with >>>>>> a discriminator, then switches to a wide-open PI filter once the phase >>>>>> stops hopping around, then when the phase settles in it stops down the >>>>>> gain to whatever the preset value is). >>>>>> >>>>>> The problem is holding lock -- they can't get it to stay locked unless >>>>>> the bandwidth is above one or two Hz, while mine stays locked just fine >>>>>> on my 12.5kHz crystal derived signal. Since this is very symptomatic of >>>>>> the signal generator not being in good shape, I'm thinking in that >>>>>> direction. >>>>>> >>>>>> I suppose they could have issues with their processor crystal -- but >>>>>> it'd have to be exceedingly sick. >>>>> --- >>>>> Why not lend them your generator and let then check their Wavetek >>>>> against it? >>>> Not a bad idea, except that it's cobbled together on a protoboard, and >>>> they're several hundred miles away. >>>> >>> Bad idea indeed! >>> You'd have a lot of jitter on the parts' arrival time... >> >> --- >> What do you mean? >> > >Try wiring something on those white protoboards then send this 1000 >miles away through UPS and see if/when parts arrive... You might expect >some group delay distortion :-) IOW some jitter on parts arrival time--- Agreed. What I thought he was referring to was a circuit cobbled together on a piece of perfboard, which can easily be cleaned up and ruggedized to the point where it can be shipped anywhere and arrive in the same shape it left. Unless, of course, it's damaged by a mule stepping on it or something like that. -- JF
Reply by ●November 24, 20112011-11-24
On Thu, 24 Nov 2011 06:08:49 -0600, John Fields <jfields@austininstruments.com> wrote:>On Thu, 24 Nov 2011 09:22:04 +0100, Fred Bartoli <" "> wrote: >[snip]>> >>Try wiring something on those white protoboards then send this 1000 >>miles away through UPS and see if/when parts arrive... You might expect >>some group delay distortion :-) IOW some jitter on parts arrival time > >--- >Agreed. > >What I thought he was referring to was a circuit cobbled together on a >piece of perfboard, which can easily be cleaned up and ruggedized to >the point where it can be shipped anywhere and arrive in the same >shape it left. > >Unless, of course, it's damaged by a mule stepping on it or something >like that.To get that you must ship USPS ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●November 24, 20112011-11-24
Jim Thompson wrote:> > On Thu, 24 Nov 2011 06:08:49 -0600, John Fields > ?jfields@austininstruments.com? wrote: > > ?On Thu, 24 Nov 2011 09:22:04 +0100, Fred Bartoli ?" "? wrote: > ? > [snip] > ?? > ??Try wiring something on those white protoboards then send this 1000 > ??miles away through UPS and see if/when parts arrive... You might expect > ??some group delay distortion :-) IOW some jitter on parts arrival time > ? > ?--- > ?Agreed. > ? > ?What I thought he was referring to was a circuit cobbled together on a > ?piece of perfboard, which can easily be cleaned up and ruggedized to > ?the point where it can be shipped anywhere and arrive in the same > ?shape it left. > ? > ?Unless, of course, it's damaged by a mule stepping on it or something > ?like that. > > To get that you must ship USPS ;-)Not always. My dad had ordered one of those round TV antennas. It was shipped UPS. The box arrived with tire marks and was taped back together. The box was full of broken plastic & twisted metal. Then they tried to claim that was the way they recieved it from the shipper. Then there was the time they were on strike, and held about $250,000 worth of our shipments fro several weeks while our customers raised hell. After that a lot of our customers insisted on shipping by Fedex, or by truck. -- You can't have a sense of humor, if you have no sense.
Reply by ●November 24, 20112011-11-24
On Thu, 24 Nov 2011 10:43:01 -0500, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:> >Jim Thompson wrote: >> >> On Thu, 24 Nov 2011 06:08:49 -0600, John Fields >> ?jfields@austininstruments.com? wrote: >> >> ?On Thu, 24 Nov 2011 09:22:04 +0100, Fred Bartoli ?" "? wrote: >> ? >> [snip] >> ?? >> ??Try wiring something on those white protoboards then send this 1000 >> ??miles away through UPS and see if/when parts arrive... You might expect >> ??some group delay distortion :-) IOW some jitter on parts arrival time >> ? >> ?--- >> ?Agreed. >> ? >> ?What I thought he was referring to was a circuit cobbled together on a >> ?piece of perfboard, which can easily be cleaned up and ruggedized to >> ?the point where it can be shipped anywhere and arrive in the same >> ?shape it left. >> ? >> ?Unless, of course, it's damaged by a mule stepping on it or something >> ?like that. >> >> To get that you must ship USPS ;-) > > > Not always. My dad had ordered one of those round TV antennas. It >was shipped UPS. The box arrived with tire marks and was taped back >together. The box was full of broken plastic & twisted metal. Then >they tried to claim that was the way they recieved it from the shipper. > > Then there was the time they were on strike, and held about $250,000 >worth of our shipments fro several weeks while our customers raised >hell. After that a lot of our customers insisted on shipping by Fedex, >or by truck.I avoid UPS also. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●November 24, 20112011-11-24
On Thu, 24 Nov 2011 08:55:51 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Thu, 24 Nov 2011 10:43:01 -0500, "Michael A. Terrell" ><mike.terrell@earthlink.net> wrote: > >> >>Jim Thompson wrote: >>> >>> On Thu, 24 Nov 2011 06:08:49 -0600, John Fields >>> ?jfields@austininstruments.com? wrote: >>> >>> ?On Thu, 24 Nov 2011 09:22:04 +0100, Fred Bartoli ?" "? wrote: >>> ? >>> [snip] >>> ?? >>> ??Try wiring something on those white protoboards then send this 1000 >>> ??miles away through UPS and see if/when parts arrive... You might expect >>> ??some group delay distortion :-) IOW some jitter on parts arrival time >>> ? >>> ?--- >>> ?Agreed. >>> ? >>> ?What I thought he was referring to was a circuit cobbled together on a >>> ?piece of perfboard, which can easily be cleaned up and ruggedized to >>> ?the point where it can be shipped anywhere and arrive in the same >>> ?shape it left. >>> ? >>> ?Unless, of course, it's damaged by a mule stepping on it or something >>> ?like that. >>> >>> To get that you must ship USPS ;-) >> >> >> Not always. My dad had ordered one of those round TV antennas. It >>was shipped UPS. The box arrived with tire marks and was taped back >>together. The box was full of broken plastic & twisted metal. Then >>they tried to claim that was the way they recieved it from the shipper. >> >> Then there was the time they were on strike, and held about $250,000 >>worth of our shipments fro several weeks while our customers raised >>hell. After that a lot of our customers insisted on shipping by Fedex, >>or by truck. > >I avoid UPS also. > > ...Jim ThompsonOne thing I forgot to mention... when I receive a package with exterior damage I photograph it before opening, then photograph each step of opening... never had a claim denied. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
