Re: [time-nuts] Phase noise measurement (was - no subject)
Hi I have the Hp phase noise system with the 35601A but use most the time the Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? Thanks Bert Kehren In a message dated 8/20/2010 6:54:05 P.M. Eastern Daylight Time, jmi...@pop.net writes: Would anyone else like to suggest a known good low phase noise buffer amplifier? Maybe something from a Fred Walls paper? You can always build HF isolation amps by rigging MMICs and attenuators together, but this will not reliably get you below -160 dBc/Hz. Bruce G. has given some good advice in this regard, with some circuit designs at http://www.ko4bb.com/~bruce/IsolationAmplifiers.html and elsewhere. I'm a fan of this version (also from Bruce): http://www.ke5fx.com/norton.htm This one has the advantage of simplicity. No weird parts, nothing that is likely to be out of production or hard to find, and dirt cheap. I've measured the broadband floor at near -170 dBc/Hz at 10 MHz, and its noise contribution at 100 Hz is below what the 3048A can see. These figures are adequate to measure any 10811-class OCXOs. A practical PN measurement system for 10811-class oscillators can be made by building two of those amplifiers and using them to drive pretty much any random double-balanced mixer found on eBay with +10 dBm LO specs or more. Both ports should be driven strongly to reject AM artifacts and avoid degrading the excellent noise floor offered by the amps. I'd hit the LO port with +10 to +12 dBm and the RF port with at least 0 dBm. Then, see the Wenzel app note here ( http://www.wenzel.com/documents/measuringphasenoise.htm ) to lock the two oscillators in quadrature and amplify the resulting baseband output. Any of several sound-card FFT programs can be used to generate an output graph, although if you want absolute calibration in dBc/Hz you need to be prepared to sweep the actual test setup from mixer output to FFT input to watch for various sources of flatness error. A combination of an AD7760-EVAL board and a Digilent Nexys2 can be used to construct an excellent baseband digitizer for the DC-1 MHz spectrum, but most of the time a good-quality 192-kHz sound card is fine for this sort of work. Most good crystal oscillators reach their broadband floor by 10 kHz, so there's no real need to go out to 1 MHz or more. -- john, KE5FX ___ 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] Phase noise measurement (was - no subject)
http://cgi.ebay.com/5-pcs-N-Channel-Transistor-2SK369-K369-Low-Noise-BL-/150471697656 Stanley - Original Message From: ewkeh...@aol.com ewkeh...@aol.com To: time-nuts@febo.com Sent: Sat, August 21, 2010 6:07:25 AM Subject: Re: [time-nuts] Phase noise measurement (was - no subject) Hi I have the Hp phase noise system with the 35601A but use most the time the Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? Thanks Bert Kehren In a message dated 8/20/2010 6:54:05 P.M. Eastern Daylight Time, jmi...@pop.net writes: Would anyone else like to suggest a known good low phase noise buffer amplifier? Maybe something from a Fred Walls paper? You can always build HF isolation amps by rigging MMICs and attenuators together, but this will not reliably get you below -160 dBc/Hz. Bruce G. has given some good advice in this regard, with some circuit designs at http://www.ko4bb.com/~bruce/IsolationAmplifiers.html and elsewhere. I'm a fan of this version (also from Bruce): http://www.ke5fx.com/norton.htm This one has the advantage of simplicity. No weird parts, nothing that is likely to be out of production or hard to find, and dirt cheap. I've measured the broadband floor at near -170 dBc/Hz at 10 MHz, and its noise contribution at 100 Hz is below what the 3048A can see. These figures are adequate to measure any 10811-class OCXOs. A practical PN measurement system for 10811-class oscillators can be made by building two of those amplifiers and using them to drive pretty much any random double-balanced mixer found on eBay with +10 dBm LO specs or more. Both ports should be driven strongly to reject AM artifacts and avoid degrading the excellent noise floor offered by the amps. I'd hit the LO port with +10 to +12 dBm and the RF port with at least 0 dBm. Then, see the Wenzel app note here ( http://www.wenzel.com/documents/measuringphasenoise.htm ) to lock the two oscillators in quadrature and amplify the resulting baseband output. Any of several sound-card FFT programs can be used to generate an output graph, although if you want absolute calibration in dBc/Hz you need to be prepared to sweep the actual test setup from mixer output to FFT input to watch for various sources of flatness error. A combination of an AD7760-EVAL board and a Digilent Nexys2 can be used to construct an excellent baseband digitizer for the DC-1 MHz spectrum, but most of the time a good-quality 192-kHz sound card is fine for this sort of work. Most good crystal oscillators reach their broadband floor by 10 kHz, so there's no real need to go out to 1 MHz or more. -- john, KE5FX ___ 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] Phase noise measurement (was - no subject)
The Wenzel Audio amp is a little noisier than it need be and it has a poor PSRR, so that a very low noise power supply with low ripple is essential. Its not too hard to improve the PSRR and the input noise of such a current feedback amplifier. There are JFETS (IF9030) with similar noise floors and significantly lower flicker noise. However the minimum order from Interfet is about $250. For noise measurements on several JFETS (including the IF9030 and the 2SK369) see: /Ultra-Low-Noise High Input Impedance Amplifier for Low-Frequency Measurement Applications/ Felix A Levinson, IEEE Transactions on Circuits and Systems Vol 55 No 7, August 2008 pp1815-1821. Bruce ewkeh...@aol.com wrote: Hi I have the Hp phase noise system with the 35601A but use most the time the Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? Thanks Bert Kehren In a message dated 8/20/2010 6:54:05 P.M. Eastern Daylight Time, jmi...@pop.net writes: Would anyone else like to suggest a known good low phase noise buffer amplifier? Maybe something from a Fred Walls paper? You can always build HF isolation amps by rigging MMICs and attenuators together, but this will not reliably get you below -160 dBc/Hz. Bruce G. has given some good advice in this regard, with some circuit designs at http://www.ko4bb.com/~bruce/IsolationAmplifiers.html and elsewhere. I'm a fan of this version (also from Bruce): http://www.ke5fx.com/norton.htm This one has the advantage of simplicity. No weird parts, nothing that is likely to be out of production or hard to find, and dirt cheap. I've measured the broadband floor at near -170 dBc/Hz at 10 MHz, and its noise contribution at 100 Hz is below what the 3048A can see. These figures are adequate to measure any 10811-class OCXOs. A practical PN measurement system for 10811-class oscillators can be made by building two of those amplifiers and using them to drive pretty much any random double-balanced mixer found on eBay with +10 dBm LO specs or more. Both ports should be driven strongly to reject AM artifacts and avoid degrading the excellent noise floor offered by the amps. I'd hit the LO port with +10 to +12 dBm and the RF port with at least 0 dBm. Then, see the Wenzel app note here ( http://www.wenzel.com/documents/measuringphasenoise.htm ) to lock the two oscillators in quadrature and amplify the resulting baseband output. Any of several sound-card FFT programs can be used to generate an output graph, although if you want absolute calibration in dBc/Hz you need to be prepared to sweep the actual test setup from mixer output to FFT input to watch for various sources of flatness error. A combination of an AD7760-EVAL board and a Digilent Nexys2 can be used to construct an excellent baseband digitizer for the DC-1 MHz spectrum, but most of the time a good-quality 192-kHz sound card is fine for this sort of work. Most good crystal oscillators reach their broadband floor by 10 kHz, so there's no real need to go out to 1 MHz or more. -- john, KE5FX ___ 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] Phase noise measurement (was - no subject)
On all phase noise measurements I use AGM batteries. specially for the signal source to be measured. Keep six 12 V batteries for that around, every thing from 7 to 20 Amps. Bert In a message dated 8/21/2010 7:33:57 A.M. Eastern Daylight Time, bruce.griffi...@xtra.co.nz writes: The Wenzel Audio amp is a little noisier than it need be and it has a poor PSRR, so that a very low noise power supply with low ripple is essential. Its not too hard to improve the PSRR and the input noise of such a current feedback amplifier. There are JFETS (IF9030) with similar noise floors and significantly lower flicker noise. However the minimum order from Interfet is about $250. For noise measurements on several JFETS (including the IF9030 and the 2SK369) see: /Ultra-Low-Noise High Input Impedance Amplifier for Low-Frequency Measurement Applications/ Felix A Levinson, IEEE Transactions on Circuits and Systems Vol 55 No 7, August 2008 pp1815-1821. Bruce ewkeh...@aol.com wrote: Hi I have the Hp phase noise system with the 35601A but use most the time the Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? Thanks Bert Kehren In a message dated 8/20/2010 6:54:05 P.M. Eastern Daylight Time, jmi...@pop.net writes: Would anyone else like to suggest a known good low phase noise buffer amplifier? Maybe something from a Fred Walls paper? You can always build HF isolation amps by rigging MMICs and attenuators together, but this will not reliably get you below -160 dBc/Hz. Bruce G. has given some good advice in this regard, with some circuit designs at http://www.ko4bb.com/~bruce/IsolationAmplifiers.html and elsewhere. I'm a fan of this version (also from Bruce): http://www.ke5fx.com/norton.htm This one has the advantage of simplicity. No weird parts, nothing that is likely to be out of production or hard to find, and dirt cheap. I've measured the broadband floor at near -170 dBc/Hz at 10 MHz, and its noise contribution at 100 Hz is below what the 3048A can see. These figures are adequate to measure any 10811-class OCXOs. A practical PN measurement system for 10811-class oscillators can be made by building two of those amplifiers and using them to drive pretty much any random double-balanced mixer found on eBay with +10 dBm LO specs or more. Both ports should be driven strongly to reject AM artifacts and avoid degrading the excellent noise floor offered by the amps. I'd hit the LO port with +10 to +12 dBm and the RF port with at least 0 dBm. Then, see the Wenzel app note here ( http://www.wenzel.com/documents/measuringphasenoise.htm ) to lock the two oscillators in quadrature and amplify the resulting baseband output. Any of several sound-card FFT programs can be used to generate an output graph, although if you want absolute calibration in dBc/Hz you need to be prepared to sweep the actual test setup from mixer output to FFT input to watch for various sources of flatness error. A combination of an AD7760-EVAL board and a Digilent Nexys2 can be used to construct an excellent baseband digitizer for the DC-1 MHz spectrum, but most of the time a good-quality 192-kHz sound card is fine for this sort of work. Most good crystal oscillators reach their broadband floor by 10 kHz, so there's no real need to go out to 1 MHz or more. -- john, KE5FX ___ 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] Phase noise measurement (was - no subject)
In message 4a8e.56751f36.39a11...@aol.com, ewkeh...@aol.com writes: On all phase noise measurements I use AGM batteries. Be aware that chemical batteries can be incredibly noisy, in particular wet or semi-wet types. It is not periodic noise, so for PN measurements with sensible averaging periods it probably does not matter. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Phase noise measurement (was - no subject)
On 22 August 2010 00:07, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 4a8e.56751f36.39a11...@aol.com, ewkeh...@aol.com writes: On all phase noise measurements I use AGM batteries. Be aware that chemical batteries can be incredibly noisy, in particular wet or semi-wet types. Dilithium Crystals are the only way to go on this. Just bolt a good sized one in the Warp drive and feed the cross-phase out though the interplanator and you get some really quiet power. Just be careful not to short it out or we will all have a bit of you come to visit us :) Steve It is not periodic noise, so for PN measurements with sensible averaging periods it probably does not matter. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Administrivia: Removing/Editing Postings
Every now and then I get a request asking that I remove a post from the time-nuts list archive because it was either meant for to an individual rather than the list, or it inadvertently included personal information. There is no easy way for me to remove a message from the archives; doing so screws up the indexing and requires a lot of manual effort. It's a bit easier to edit a message, e.g. to remove a mailing address, but even that requires me to grep through files to find the message and then edit in multiple places. Everyone should be aware that there are at least a couple of external archive sites subscribed to the time-nuts list, such as mail-archive.com. I have no control over those sites, so my fixing a posting on the primary archive will not change their archives. So, here is my policy: Upon request, and on a time-available basis (which may take a while), I'll attempt to remove personal identifying information such as addresses and phone numbers from messages in the febo.com time-nuts archive. The request must be made within 10 days of the posting date, using the same email address used for the posting (so I can verify authenticity), and provide the date and time the message was posted, the subject line, and of course the personally identifying information to be redacted. I will not remove postings entirely, or make changes other than to protect personal identifying information. And remember that changes in the febo.com archive will not affect other archive sites. I'm reminded of a great hacker folk song called Threes in which one of the verses goes: Three things hold no secrets: Files that somehow hit the 'net, Your boss's secretary, And the third thing I forget. There is much truth in those lines. John ___ 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] Phase noise measurement (was - no subject)
I am not seeing it, what should I use to measure it 3561 and 7 spec analyzer do not show it? Bert In a message dated 8/21/2010 8:07:41 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 4a8e.56751f36.39a11...@aol.com, ewkeh...@aol.com writes: On all phase noise measurements I use AGM batteries. Be aware that chemical batteries can be incredibly noisy, in particular wet or semi-wet types. It is not periodic noise, so for PN measurements with sensible averaging periods it probably does not matter. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Phase noise measurement (was - no subject)
Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? NXP BF862, available from digi-key. I have used it in a similar hookup with good success. Its virtue is the low noise voltage AND low input capacitance at the same time. You could deploy MANY of them in parallel until you get into the capacitance range of a single Interfet device. One heroic effort for audio is here: http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 I currently use 3 pairs of SSM2210 in front of a AD797. regards, Gerhard ___ 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] Phase noise measurement (was - no subject)
Hi A simple gain of 20 (26 db) amp using an OP-37 does a pretty good job in front of a spectrum analyzer. For a sound card you need more gain. Bob On Aug 21, 2010, at 11:42 AM, dk...@arcor.de wrote: Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? NXP BF862, available from digi-key. I have used it in a similar hookup with good success. Its virtue is the low noise voltage AND low input capacitance at the same time. You could deploy MANY of them in parallel until you get into the capacitance range of a single Interfet device. One heroic effort for audio is here: http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 I currently use 3 pairs of SSM2210 in front of a AD797. regards, Gerhard ___ 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] Phase noise measurement (was - no subject)
Thanks Bert In a message dated 8/21/2010 11:43:53 A.M. Eastern Daylight Time, dk...@arcor.de writes: Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? NXP BF862, available from digi-key. I have used it in a similar hookup with good success. Its virtue is the low noise voltage AND low input capacitance at the same time. You could deploy MANY of them in parallel until you get into the capacitance range of a single Interfet device. One heroic effort for audio is here: http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 I currently use 3 pairs of SSM2210 in front of a AD797. regards, Gerhard ___ 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] Phase noise measurement (was - no subject)
On Aug 20, 2010, at 11:17 AM, Rick Karlquist wrote: The AMC-123 can also be homebrewed by reading the patent, which is listed on the data sheet. I found it here: http://www.freepatentsonline.com/3624536.pdf Having read the patent, I find I'm still weak enough in the area of discrete amplifier design that I'd have low confidence of creating an amplifier with the required phase noise, gain, isolation and compression specifications. Assuming the simple amplifier in Figure 1, I think I'm make or break the design (more likely the latter) by selecting a suitable in-production replacement for the 2N5109, figuring out the required turns ratio of autotransformer L1, biasing the transistor amplifier correctly, etc. I'd have no problem building it; if I identified off-the-shelf magnetics then I could even build a whole bunch of them, as I design PCBs for a living (mostly GPS stuff; I can lay out the microwave stuff as long as a smart RF guy comes up with the necessary LNA circuit topology), and I even have a bit of experience designing mechanical stuff (i.e., in case it wanted to be in a nice machined aluminum shield/heat-sink box, though my CNC mill is presently in pieces so I'd need to farm out mechanical fabrication). I'm just weak in the analog/RF design area so far. Since the Q: Which amplifier? A: AMC-123! thing appears to be a FAQ, and that patent may be old enough to have expired, I wonder if the world wants a nice plug-and-play TIME-NUTS-123 amplifier based on the Norton patent, designed with currently-available off-the-shelf components (aside from the custom PCB and possibly enclosure), which could be made in smallish batches, characterized by somebody with the right equipment, and sold at a reasonable price to help folks cobble together their home-brewed phase noise measurement and frequency reference distribution systems. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
On Aug 20, 2010, at 3:41 PM, Rick Karlquist wrote: It might still be available through Tyco/MAcom. They have continued to make selected Anzac components. There was also an AM-123, which was a TO-something can version. My first quick scan didn't turn up any offered for sale, though I did dig up the datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/184840/MACOM/AM-123/+074853VKvwOxcER.tvC+/datasheet.pdf -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
On Aug 20, 2010, at 5:11 PM, John Miles wrote: Also, it looks like you (Mark) are only about an hour from Cerritos, where the MUD ( http://www.microwaveupdate.org ) conference will be held at the end of October. This could be one option for you. As part of the $35 registration cost, you get access to a test lab set up to help attendees measure noise figure, PN, etc. on any homebrew or commercial gear they wish to bring. Interesting. I still think I'd like to be able to measure low phase noise signal sources at home if practical. In particular, I've been toying with the idea of starting my own little company on the side, making and selling ham-radio-related/test-equipment-related stuff that seems to be missing from the market, as a (probably small but hopefully positive) secondary source of income and an excuse to design, build, accumulate (and deduct!) fun electronic equipment. My desire to learn to characterize phase noise stems from the idea that some of my products would be things whose phase noise should be specified, and it wouldn't be right for me to leech off other people's test equipment and effort if I plan to make a buck at it. Thus, I feel the need to learn how to do it myself, and then use that ability to add some value to the world in some manner. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
In message 7c37.12cdef25.39a12...@aol.com, ewkeh...@aol.com writes: I am not seeing it, what should I use to measure it 3561 and 7 spec analyzer do not show it? It is probably the 3561 not the 70k that has the best chance. I am not aware of the precise characteristics of the noise, but it sounds somewhat like a boiling pot. I became aware of it first time when I ran a small class-A audio amplifier from a couple of, probably too, small VRLA's some years ago, just for the fun of it. With no input signal, the speakers would gurgle faintly and it took me some time to locate the source of the noise to the batteries. I would guess its amplitude correlates with the ratio of discharge current to plate area, since it is chemical/mechanical in nature. These days, I would build a super-cap battery instead if I needed a low-power PSU with low noise. Poul-Henning PS: also be aware that almost all VRLA's have a very nasty resonance frequency somewhere in the low MHz band. If you are after low noise, you should always decouple the battery good poly/plastic caps right at the terminals. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Phase noise measurement (was - no subject)
Hi I suspect you will have to hand wind the magnetics. The 5109 was still in production last time I shopped for them. Bob On Aug 21, 2010, at 1:52 PM, Mark J. Blair n...@nf6x.net wrote: On Aug 20, 2010, at 11:17 AM, Rick Karlquist wrote: The AMC-123 can also be homebrewed by reading the patent, which is listed on the data sheet. I found it here: http://www.freepatentsonline.com/3624536.pdf Having read the patent, I find I'm still weak enough in the area of discrete amplifier design that I'd have low confidence of creating an amplifier with the required phase noise, gain, isolation and compression specifications. Assuming the simple amplifier in Figure 1, I think I'm make or break the design (more likely the latter) by selecting a suitable in-production replacement for the 2N5109, figuring out the required turns ratio of autotransformer L1, biasing the transistor amplifier correctly, etc. I'd have no problem building it; if I identified off-the-shelf magnetics then I could even build a whole bunch of them, as I design PCBs for a living (mostly GPS stuff; I can lay out the microwave stuff as long as a smart RF guy comes up with the necessary LNA circuit topology), and I even have a bit of experience designing mechanical stuff (i.e., in case it wanted to be in a nice machined aluminum shield/heat-sink box, though my CNC mill is presently in pieces so I'd need to farm out mechanical fabrication). I'm just weak in the analog/RF design area so far. Since the Q: Which amplifier? A: AMC-123! thing appears to be a FAQ, and that patent may be old enough to have expired, I wonder if the world wants a nice plug-and-play TIME-NUTS-123 amplifier based on the Norton patent, designed with currently-available off-the-shelf components (aside from the custom PCB and possibly enclosure), which could be made in smallish batches, characterized by somebody with the right equipment, and sold at a reasonable price to help folks cobble together their home-brewed phase noise measurement and frequency reference distribution systems. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
Hi There are a number of articles on the web detailing the art of getting one of these to work. Since it's broad band feedback you need to be a little careful with the layout and the transformer. Bob On Aug 21, 2010, at 2:50 PM, Mark J. Blair n...@nf6x.net wrote: On Aug 21, 2010, at 11:30 AM, Bob Camp wrote: I suspect you will have to hand wind the magnetics. Ah, bummer. I thought that the two 1:5 transformers specified in the patent might be realized with this part for an amplifier for use at 10 MHz only: http://minicircuits.com/pdfs/TT25-1.pdf However, I got the feeling that autotransformer L1 might need some odd turns ratio to get the impedance matching right. Am I anywhere close to making sense, or am I still droolingly clueless? :) The 5109 was still in production last time I shopped for them. I didn't find them at Digi-Key, but I just looked at Mouser and found them still available, made by Central Semiconductor: http://www.centralsemi.com/PDFs/products/2n5109.pdf I'm so accustomed to tiny surface-mount stuff in my day job, that I'm always surprised to find anything through-hole still in production! -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
On Aug 21, 2010, at 12:04 PM, Bob Camp wrote: There are a number of articles on the web detailing the art of getting one of these to work. Since it's broad band feedback you need to be a little careful with the layout and the transformer. Thanks, I'll continue digging. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
It's still being made by Tyco / MaCOM: http://www.macomtech.com/datasheets/AM-123_AMC-123.pdf Adrian Mark J. Blair schrieb: On Aug 20, 2010, at 3:41 PM, Rick Karlquist wrote: It might still be available through Tyco/MAcom. They have continued to make selected Anzac components. There was also an AM-123, which was a TO-something can version. My first quick scan didn't turn up any offered for sale, though I did dig up the datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/184840/MACOM/AM-123/+074853VKvwOxcER.tvC+/datasheet.pdf ___ 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] Phase noise measurement (was - no subject)
On Aug 21, 2010, at 12:10 PM, Adrian wrote: It's still being made by Tyco / MaCOM: http://www.macomtech.com/datasheets/AM-123_AMC-123.pdf Thanks! According to Avnet (the only one of their US distributors where I found a price posted online), the price is around $600 each at quantity 5 for the SMA connector version. !! I think I'll continue investigating a homebrew implementation for now! -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Phase noise measurement (was - no subject)
ewkeh...@aol.com wrote: Thanks Bert In a message dated 8/21/2010 11:43:53 A.M. Eastern Daylight Time, dk...@arcor.de writes: Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? NXP BF862, available from digi-key. Don't these devices have relatively high flicker noise? I have used it in a similar hookup with good success. Its virtue is the low noise voltage AND low input capacitance at the same time. You could deploy MANY of them in parallel until you get into the capacitance range of a single Interfet device. The input capacitance is relatively noncritical in this application (phase noise measurement) since it is shunted by the much larger output capacitance of the low pass filter at the mixer IF port. One heroic effort for audio is here: http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 I currently use 3 pairs of SSM2210 in front of a AD797. regards, Gerhard Bruce ___ 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] Phase noise measurement (was - no subject)
Poul-Henning Kamp wrote: In message7c37.12cdef25.39a12...@aol.com, ewkeh...@aol.com writes: I am not seeing it, what should I use to measure it 3561 and 7 spec analyzer do not show it? It is probably the 3561 not the 70k that has the best chance. I am not aware of the precise characteristics of the noise, but it sounds somewhat like a boiling pot. I became aware of it first time when I ran a small class-A audio amplifier from a couple of, probably too, small VRLA's some years ago, just for the fun of it. With no input signal, the speakers would gurgle faintly and it took me some time to locate the source of the noise to the batteries. I would guess its amplitude correlates with the ratio of discharge current to plate area, since it is chemical/mechanical in nature. These days, I would build a super-cap battery instead if I needed a low-power PSU with low noise. Poul-Henning PS: also be aware that almost all VRLA's have a very nasty resonance frequency somewhere in the low MHz band. If you are after low noise, you should always decouple the battery good poly/plastic caps right at the terminals. NIST found that NiCd cells are very quiet at least for low load currents: http://tf.nist.gov/general/pdf/1133.pdf Thus batteries are useful as low noise voltage references or for providing the relatively low base current of a BJT in a low phase noise RF amplifier. Perhaps its the gelled electrolyte that is the source of the noise problem with VLRA batteries?? Bruce ___ 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] Phase noise measurement (was - no subject)
In message 4c703124.20...@xtra.co.nz, Bruce Griffiths writes: Poul-Henning Kamp wrote: NIST found that NiCd cells are very quiet at least for low load currents: http://tf.nist.gov/general/pdf/1133.pdf Too bad they didn't include lead-acid in that test... Perhaps its the gelled electrolyte that is the source of the noise problem with VLRA batteries?? The batteries I used were pre-owned AGM, and apart from possibly the frequency spectrum, I wouldn't expect AGM/Gel to make any significant difference. The very few hints I have been able to find, talk about bubbles and mechanical shifts in the particulate matter in the electrodes but they were all trying to divine battery health from these entrails, rather than measuring the absolute magnitude of the problem. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Phase noise measurement (was - no subject)
That's not really a surprise. Alone the hermetically sealed flatpack housings don't make these a bargain... There's nothing wrong with building your own. Btw. there was an article in the German 'UKW-Berichte' (VHF Communications) 4/1977 featuring a two stage BFT66 + BFR34A Norton amp for 144 and 432 MHz. Adrian Mark J. Blair schrieb: On Aug 21, 2010, at 12:10 PM, Adrian wrote: It's still being made by Tyco / MaCOM: http://www.macomtech.com/datasheets/AM-123_AMC-123.pdf Thanks! According to Avnet (the only one of their US distributors where I found a price posted online), the price is around $600 each at quantity 5 for the SMA connector version. !! I think I'll continue investigating a homebrew implementation for now! ___ 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] Re frequency counters
It is vain to do with more that which can be done with less. In that case have a look here: http://www.uploadarchief.net/files/download/freqlogger.zip A PIC12F629 based RS-232 frequency logger. No display and can be clocked by an external 10MHz clock if needed. My version worked to 60 MHz. Joop ___ 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] Phase noise measurement (was - no subject)
Hi One thing to head back to here: What is being measured? If the DUT is only as good as a 10811 and you have a 3561a, an AD797 is overkill. That assumes you are running a RPD-1 or a high level mixer with buffers. There aren't a lot of oscillators on the surplus market that will need much better. Super amps are fine. They just are a bit beyond the minimum required to get going. Bob On Aug 21, 2010, at 3:47 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: ewkeh...@aol.com wrote: Thanks Bert In a message dated 8/21/2010 11:43:53 A.M. Eastern Daylight Time, dk...@arcor.de writes: Wenzel Audio Amp referred to in this email. Perfect! I drive with it a 3561A and a 7L5! Works for me. The only problem is getting any more 2SK369. Any recommendations? NXP BF862, available from digi-key. Don't these devices have relatively high flicker noise? I have used it in a similar hookup with good success. Its virtue is the low noise voltage AND low input capacitance at the same time. You could deploy MANY of them in parallel until you get into the capacitance range of a single Interfet device. The input capacitance is relatively noncritical in this application (phase noise measurement) since it is shunted by the much larger output capacitance of the low pass filter at the mixer IF port. One heroic effort for audio is here: http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 I currently use 3 pairs of SSM2210 in front of a AD797. regards, Gerhard Bruce ___ 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] Antenna problems
Hi group, Warren found out that the signals TB gets out of my small ceramic typ antenna are too weak. They are too noisy. So I had a look for a good antenna and found some commercial typs called choke-ring antenna. As they are really expensive is there any DIY solution avaliable? I have a lathe so its possibly to machine rings if I get the dimensions... Thanks a lot making me a nut ;) regards Peter, DG4EK ___ 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] Antenna problems
On Aug 21, 2010, at 7:15 PM, Peter Krengel wrote: Warren found out that the signals TB gets out of my small ceramic typ antenna are too weak. They are too noisy. So I had a look for a good antenna and found some commercial typs called choke-ring antenna. As they are really expensive is there any DIY solution avaliable? I think that the TBolt wants a fair amount of gain up at the antenna, based on the signal levels it reported from the roof antenna feed at work (we're in the GPS industry) compared to what I normally see from our normal GPS receivers. Mine is installed at home with a Lucent/Alcatel +26dB antenna which I believe was primarily intended for use at cellular base stations, and my TBolt sees nice, strong signals from it with about 9m of feedline. These antennas are all over eBay, both used and unused, and with or without the pole mount. The TBolt will power them with its +5V bias. An eBay search for lucent gps antenna should turn up a few antennas and several mounts at the moment. There are probably many other antennas that will work fine. I'd suggest looking around for active GPS antennas meant for outdoor fixed installations (they'll generally have a somewhat pointy radome to keep snow, birds, etc. from accumulating on them), powered by +5VDC, and with at least 20dB of gain. Used ones can be cheap. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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.
