Re: [time-nuts] filtering a 10Mhz frequency standard?
Luciano I just placed an order for some parts with an electronics distributor in the US called digikey. I happened to notice they carried the orange 10.7 Mhz IF transformers 42IF222-RC so I ordered 10 of them up to build up your filter. Should have everything late next week. Time to warm up the soldering iron and sniff some flux. Regards Paul WB8TSL On Wed, Dec 14, 2011 at 10:02 AM, paul swed paulsw...@gmail.com wrote: Boy thats nice and simple. Shame I juts placed a order for parts could have added a few 10.7 xformers to the order. On Wed, Dec 14, 2011 at 9:55 AM, Timeok tim...@timeok.it wrote: see also: http://www.timeok.it/files/10_mhz_bandpass_filter.pdf -- Luciano P. S. Paramithiotti IZ5JHJ - Original Message From: Discussion of precise time and frequency measurement time-nuts@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Date: Dec 13, 2011 10:29 PM If you are going to buffer the output, why does the filter have to be passive? Did I miss something here? Today 10MHz is in the realm of active filters. [Hey, not that I made an active filter at 10MHz.] Sensitivity is a function of the denominator. The only advantage to a LPF over a BPF is the BPF has to be centered at 10MHz, while you could bump the corner of the LPF to a higher frequency so there is less sensitivity at 10MHz This presumes you are only getting rid of harmonics and not spurs. For lowest component sensitivity, leap frog designs are best. But in continuous time designs, they require many op amps per pole. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent to you using Uebimiau Webmail version 3.11 Developed by Dave and Todd at http://www.manvel.net and http://www.tdah.us ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
see also: http://www.timeok.it/files/10_mhz_bandpass_filter.pdf -- Luciano P. S. Paramithiotti IZ5JHJ - Original Message From: Discussion of precise time and frequency measurement time-nuts@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Date: Dec 13, 2011 10:29 PM If you are going to buffer the output, why does the filter have to be passive? Did I miss something here? Today 10MHz is in the realm of active filters. [Hey, not that I made an active filter at 10MHz.] Sensitivity is a function of the denominator. The only advantage to a LPF over a BPF is the BPF has to be centered at 10MHz, while you could bump the corner of the LPF to a higher frequency so there is less sensitivity at 10MHz This presumes you are only getting rid of harmonics and not spurs. For lowest component sensitivity, leap frog designs are best. But in continuous time designs, they require many op amps per pole. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent to you using Uebimiau Webmail version 3.11 Developed by Dave and Todd at http://www.manvel.net and http://www.tdah.us ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Boy thats nice and simple. Shame I juts placed a order for parts could have added a few 10.7 xformers to the order. On Wed, Dec 14, 2011 at 9:55 AM, Timeok tim...@timeok.it wrote: see also: http://www.timeok.it/files/10_mhz_bandpass_filter.pdf -- Luciano P. S. Paramithiotti IZ5JHJ - Original Message From: Discussion of precise time and frequency measurement time-nuts@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Date: Dec 13, 2011 10:29 PM If you are going to buffer the output, why does the filter have to be passive? Did I miss something here? Today 10MHz is in the realm of active filters. [Hey, not that I made an active filter at 10MHz.] Sensitivity is a function of the denominator. The only advantage to a LPF over a BPF is the BPF has to be centered at 10MHz, while you could bump the corner of the LPF to a higher frequency so there is less sensitivity at 10MHz This presumes you are only getting rid of harmonics and not spurs. For lowest component sensitivity, leap frog designs are best. But in continuous time designs, they require many op amps per pole. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent to you using Uebimiau Webmail version 3.11 Developed by Dave and Todd at http://www.manvel.net and http://www.tdah.us ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Paul's simple filter: http://www.w1ghz.org/small_proj/small_proj.htm Mike - Original Message - From: Bob Bownes bow...@gmail.com To: li...@lazygranch.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, December 12, 2011 10:11 PM Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Paul Wade did a paper on 10Mhz GPSDO filtering for Microwave Update in October. It is in the proceedings. I don't know if it is available elsewhere. Bob On Mon, Dec 12, 2011 at 9:17 PM, li...@lazygranch.com wrote: I think you would want to avoid crystal filters due to microphonics. I've found building good LCR filters harder in real life than on paper. (I've done plenty of leapfrog active filters from LCR based designs.) I've had to make a passive LCR for ADC testing and secondary (parasitic elements of nonideal component) come into play. Nowadays I just buy COTS. --Original Message-- From: Chris Albertson Sender: time-nuts-boun...@febo.com To: Discussion of precise time and frequency measurement ReplyTo: Discussion of precise time and frequency measurement Subject: [time-nuts] filtering a 10Mhz frequency standard? Sent: Dec 12, 2011 5:54 PM What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
I just ordered the parts for this filter from Mouser Electronics. ~ $30 plus shipping including a shiny new Pomona box. qty 2 542-78F1R0-RC RF Inductors 1.0uH 10% @ $0.18 ea qty 2 140-50S5-271J-RC Ceramic Disc Capacitors 50V 270pF SL 5% Tol @ $0.14 ea qty 1 140-50S5-471J-RC Ceramic Disc Capacitors 50V 470pF SL 5% Tol @ $0.11 ea qty 1 565-3752 Test Connectors SHLD BOX BNC (M/F) @ $29.12 ea (ouch!) That's 75 cents in parts plus the box. Once assembled I'll sweep it with the network analyzer and report back on tweaks made to get it closer to the simulation. -Bob On Tue, Dec 13, 2011 at 4:08 AM, n1...@burlingtontelecom.net wrote: Paul's simple filter: http://www.w1ghz.org/small_**proj/small_proj.htmhttp://www.w1ghz.org/small_proj/small_proj.htm Mike - Original Message - From: Bob Bownes bow...@gmail.com To: li...@lazygranch.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, December 12, 2011 10:11 PM Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Paul Wade did a paper on 10Mhz GPSDO filtering for Microwave Update in October. It is in the proceedings. I don't know if it is available elsewhere. Bob On Mon, Dec 12, 2011 at 9:17 PM, li...@lazygranch.com wrote: I think you would want to avoid crystal filters due to microphonics. I've found building good LCR filters harder in real life than on paper. (I've done plenty of leapfrog active filters from LCR based designs.) I've had to make a passive LCR for ADC testing and secondary (parasitic elements of nonideal component) come into play. Nowadays I just buy COTS. --Original Message-- From: Chris Albertson Sender: time-nuts-boun...@febo.com To: Discussion of precise time and frequency measurement ReplyTo: Discussion of precise time and frequency measurement Subject: [time-nuts] filtering a 10Mhz frequency standard? Sent: Dec 12, 2011 5:54 PM What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Not to take anything away from Paul's design, but if you have to buy the box new, for three bucks more you can get a complete 10.7 MHz LPF with BNC connectors from MiniCircuits (Model BLP-10.7+, $32.95). They also have quite a few other useful cutoff frequencies -- 1.9 MHz, 5 MHz, 30 MHz, etc. John On 12/13/2011 9:08 AM, Robert Darlington wrote: I just ordered the parts for this filter from Mouser Electronics. ~ $30 plus shipping including a shiny new Pomona box. qty 2 542-78F1R0-RC RF Inductors 1.0uH 10% @ $0.18 ea qty 2 140-50S5-271J-RC Ceramic Disc Capacitors 50V 270pF SL 5% Tol @ $0.14 ea qty 1 140-50S5-471J-RC Ceramic Disc Capacitors 50V 470pF SL 5% Tol @ $0.11 ea qty 1 565-3752 Test Connectors SHLD BOX BNC (M/F) @ $29.12 ea (ouch!) That's 75 cents in parts plus the box. Once assembled I'll sweep it with the network analyzer and report back on tweaks made to get it closer to the simulation. -Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
If your intent is to take full advantage of the long term as well as short term stability of a reference oscillator, the best approach is a low pass filter that will have small (and stable) phase shift at 10 MHz. Most bandpass filters will have enough temperature sensitivity of the phase shift through the filter to degrade the performance of an Rb. It may look fine on the scope but would not give you good long term adev. If you don't care about long term stability, you probably do not need an Rb in the first place. If you only need good long term frequency stability and phase (or absolute time) is of no concern, then the type of filter (and whether there is a filter or not) does not matter. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Chris Albertson albertson.ch...@gmail.com Sender: time-nuts-boun...@febo.com Date: Mon, 12 Dec 2011 17:54:09 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] filtering a 10Mhz frequency standard? What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
see also: www.timeok.it/files/10_mhz_bandpass_filter.pdf Luciano Luciano P. S. Paramithiotti IZ5JHJ - Original Message From: n1...@burlingtontelecom.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Date: Dec 13, 2011 12:12 PM Paul's simple filter: http://www.w1ghz.org/small_proj/small_proj.htm Mike - Original Message - From: quot;Bob Bownesquot; lt;bow...@gmail.comgt; To: lt;li...@lazygranch.comgt;; quot;Discussion of precise time and frequency measurementquot; lt;time-nuts@febo.comgt; Sent: Monday, December 12, 2011 10:11 PM Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? Paul Wade did a paper on 10Mhz GPSDO filtering for Microwave Update in October. It is in the proceedings. I don't know if it is available elsewhere. Bob On Mon, Dec 12, 2011 at 9:17 PM, lt;li...@lazygranch.comgt; wrote: gt; I think you would want to avoid crystal filters due to microphonics. gt; gt; I've found building good LCR filters harder in real life than on paper. gt; (I've done plenty of leapfrog active filters from LCR based designs.) I've gt; had to make a passive LCR for ADC testing and secondary (parasitic gt; elements of nonideal component) come into play. Nowadays I just buy COTS. gt; gt; gt; --Original Message-- gt; From: Chris Albertson gt; Sender: time-nuts-boun...@febo.com gt; To: Discussion of precise time and frequency measurement gt; ReplyTo: Discussion of precise time and frequency measurement gt; Subject: [time-nuts] filtering a 10Mhz frequency standard? gt; Sent: Dec 12, 2011 5:54 PM gt; gt; What is the best practice for filtering a 10Mhz sine wave frequency gt; standard? I've read that you can do more harm than good. Filter gt; parts (caps, resistors and so on) are all temperature sensitive. But gt; all those $40 Rb oscillators are putting out a pretty rough looking gt; sine wave. gt; gt; Are some types of filters better. I thought about a crystal filters. gt; gt; -- gt; gt; Chris Albertson gt; Redondo Beach, California gt; gt; ___ gt; time-nuts mailing list -- time-nuts@febo.com gt; To unsubscribe, go to gt; https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts gt; and follow the instructions there. gt; ___ gt; time-nuts mailing list -- time-nuts@febo.com gt; To unsubscribe, go to gt; https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts gt; and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent to you using Uebimiau Webmail version 3.11 Developed by Dave and Todd at http://www.manvel.net and http://www.tdah.us ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] filtering a 10Mhz frequency standard?
I reported a filter design I was working on back in November, using 10 base T LAN filter modules. The first experimental air-wired unit with two modules got to about -75 dBc at 30 MHz, rising to -65 dBc at 70 MHz. After building the same circuit with shielded compartments, it ran about -85 dBc flat over this range, but it should have been over 100. The weak link turned out to be the cross-talk within the modules themselves - there are two 17 MHz LPF sections in each, and I cascaded them all. Four separate modules cascaded, using only the Tx portion of each, should reach about 120 dBc rejection, with about 6 dB insertion loss. The original two-module circuit (or maybe even a single one) would probably suffice for most applications. I haven't yet impedance matched the 100 ohm differential filters to the 50 ohm cable environment - I'm thinking it may not even be necessary. If you have any old LAN cards, hubs, or routers around, you may already have some nice free LPFs for this purpose. The box to put them in (packaging cost) is another matter. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Hi Regardless of the design, what ever filter you use will be sensitive to load. Hooking up a few dozen instruments to a standard line with BNC T's is unlikely to present 50 ohms to the filter. The more complex the filter, generally the more sensitive it will be Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ed breya Sent: Tuesday, December 13, 2011 12:07 PM To: time-nuts@febo.com Subject: [time-nuts] filtering a 10Mhz frequency standard? I reported a filter design I was working on back in November, using 10 base T LAN filter modules. The first experimental air-wired unit with two modules got to about -75 dBc at 30 MHz, rising to -65 dBc at 70 MHz. After building the same circuit with shielded compartments, it ran about -85 dBc flat over this range, but it should have been over 100. The weak link turned out to be the cross-talk within the modules themselves - there are two 17 MHz LPF sections in each, and I cascaded them all. Four separate modules cascaded, using only the Tx portion of each, should reach about 120 dBc rejection, with about 6 dB insertion loss. The original two-module circuit (or maybe even a single one) would probably suffice for most applications. I haven't yet impedance matched the 100 ohm differential filters to the 50 ohm cable environment - I'm thinking it may not even be necessary. If you have any old LAN cards, hubs, or routers around, you may already have some nice free LPFs for this purpose. The box to put them in (packaging cost) is another matter. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] filtering a 10Mhz frequency standard?
Yes, you don't want to send un-buffered (or unprotected) signals - especially right out of a filter - out for distribution. I have found that some pieces of equipment will only take the external reference over a certain small level range, so the distribution amplifier needs to have an assortment of levels, or some that are adjustable. Each instrument should have its own line from the amplifier unit, set to the right level, or for remote sending, a power splitter port from a common line. Ed on Tue Dec 13 17:19:12 UTC 2011 Bob Camp wrote: Regardless of the design, what ever filter you use will be sensitive to load. Hooking up a few dozen instruments to a standard line with BNC T's is unlikely to present 50 ohms to the filter. The more complex the filter, generally the more sensitive it will be ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
If you are going to buffer the output, why does the filter have to be passive? Did I miss something here? Today 10MHz is in the realm of active filters. [Hey, not that I made an active filter at 10MHz.] Sensitivity is a function of the denominator. The only advantage to a LPF over a BPF is the BPF has to be centered at 10MHz, while you could bump the corner of the LPF to a higher frequency so there is less sensitivity at 10MHz This presumes you are only getting rid of harmonics and not spurs. For lowest component sensitivity, leap frog designs are best. But in continuous time designs, they require many op amps per pole. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
If your concern is harmonics, the best combination is a low pass filter that cuts high enough to have no (or negligible) group delay at 10 MHz, and one or more notch filters for the harmonics, as many as necessary to get the attenuation you desire. These filters should have no measurable effect on the fundamental. If you have phase noise or spurs near the carrier, you need a cleanup PLL with a good crystal and a narrow BW. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: gary li...@lazygranch.com Sender: time-nuts-boun...@febo.com Date: Tue, 13 Dec 2011 13:27:54 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] filtering a 10Mhz frequency standard? If you are going to buffer the output, why does the filter have to be passive? Did I miss something here? Today 10MHz is in the realm of active filters. [Hey, not that I made an active filter at 10MHz.] Sensitivity is a function of the denominator. The only advantage to a LPF over a BPF is the BPF has to be centered at 10MHz, while you could bump the corner of the LPF to a higher frequency so there is less sensitivity at 10MHz This presumes you are only getting rid of harmonics and not spurs. For lowest component sensitivity, leap frog designs are best. But in continuous time designs, they require many op amps per pole. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Come to think of it, you will have more noise if you use a LPF rather than a BPF, given noise being proportional to the square root of bandwidth. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] filtering a 10Mhz frequency standard?
What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
On 12/12/2011 5:54 PM, Chris Albertson wrote: What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. The LC filter in the TADD-1 is very effective. Mind you the coil winding information given in the parts list is incorrect. Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
I think you would want to avoid crystal filters due to microphonics. I've found building good LCR filters harder in real life than on paper. (I've done plenty of leapfrog active filters from LCR based designs.) I've had to make a passive LCR for ADC testing and secondary (parasitic elements of nonideal component) come into play. Nowadays I just buy COTS. --Original Message-- From: Chris Albertson Sender: time-nuts-boun...@febo.com To: Discussion of precise time and frequency measurement ReplyTo: Discussion of precise time and frequency measurement Subject: [time-nuts] filtering a 10Mhz frequency standard? Sent: Dec 12, 2011 5:54 PM What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] filtering a 10Mhz frequency standard?
Paul Wade did a paper on 10Mhz GPSDO filtering for Microwave Update in October. It is in the proceedings. I don't know if it is available elsewhere. Bob On Mon, Dec 12, 2011 at 9:17 PM, li...@lazygranch.com wrote: I think you would want to avoid crystal filters due to microphonics. I've found building good LCR filters harder in real life than on paper. (I've done plenty of leapfrog active filters from LCR based designs.) I've had to make a passive LCR for ADC testing and secondary (parasitic elements of nonideal component) come into play. Nowadays I just buy COTS. --Original Message-- From: Chris Albertson Sender: time-nuts-boun...@febo.com To: Discussion of precise time and frequency measurement ReplyTo: Discussion of precise time and frequency measurement Subject: [time-nuts] filtering a 10Mhz frequency standard? Sent: Dec 12, 2011 5:54 PM What is the best practice for filtering a 10Mhz sine wave frequency standard? I've read that you can do more harm than good. Filter parts (caps, resistors and so on) are all temperature sensitive. But all those $40 Rb oscillators are putting out a pretty rough looking sine wave. Are some types of filters better. I thought about a crystal filters. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
