Re: [time-nuts] VNA design
The way the 8410 was automated HP built an add on DAC module to convert the plotter outputs to digital form and used an 8350 sweeper to replace the BWO sweepers commonly used by 8410 systems and a relay controller to do the test set switching They called this rig the 'Automatic Network Analyzer' Sent from my iPhone On Jun 3, 2014, at 2:22 PM, paul swed paulsw...@gmail.com wrote: Boy this is not time-nuts and I had been deleting the thread. No problem with the thread. Just I have HP VNAs. Yes including what caught my eye the 8410 that Scott spoke of and its still operational. Heavy as heck like real equipment should be. I am curious I sort of thought the 8410 was pre micro processor and yet some how the HP85 hooked up to it?? I have the 8757 also so. Great comment by Dave on the fact that someone will give out some of the old options. Now I have to figure out what on earth that might actually mean. Regards Paul WB8TSL On Tue, Jun 3, 2014 at 12:57 PM, Dr. David Kirkby drkir...@gmail.com wrote: On 3 June 2014 16:54, Scott McGrath scmcgr...@gmail.com wrote: Where are the software options for the 8753 coming from. Agilent will not even talk about a VNA that's older than the PNA series This has been discussed on the HP/Agilent mailing list. Basically a couple of people that work at Agilent, one of whom is caes...@email.com (yes email, not gmail), will give out options for 8753 for non-commercial use. Just send him your S/N. I know he also did likewise for an older 8720 instrument (I think 8720C). Although he can, he will NOT do it for PNAs. That is one advantage of getting a used 8753/8720 over a used PNA! Agilent offered to repair my 8720D a couple of years ago, and managed to give me a quote via email as it was abundantly obvious what the problem was - a damaged thread on a test port connector. The only problem was they wanted to change the whole coupler, so it was going to cost the US equivalent of around $5000. A mate of mine sorted out the nick on the thread with a needle file!!! Dave ___ 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] VNA design
Thanks On Wed, Jun 4, 2014 at 7:29 AM, Scott McGrath scmcgr...@gmail.com wrote: The way the 8410 was automated HP built an add on DAC module to convert the plotter outputs to digital form and used an 8350 sweeper to replace the BWO sweepers commonly used by 8410 systems and a relay controller to do the test set switching They called this rig the 'Automatic Network Analyzer' Sent from my iPhone On Jun 3, 2014, at 2:22 PM, paul swed paulsw...@gmail.com wrote: Boy this is not time-nuts and I had been deleting the thread. No problem with the thread. Just I have HP VNAs. Yes including what caught my eye the 8410 that Scott spoke of and its still operational. Heavy as heck like real equipment should be. I am curious I sort of thought the 8410 was pre micro processor and yet some how the HP85 hooked up to it?? I have the 8757 also so. Great comment by Dave on the fact that someone will give out some of the old options. Now I have to figure out what on earth that might actually mean. Regards Paul WB8TSL On Tue, Jun 3, 2014 at 12:57 PM, Dr. David Kirkby drkir...@gmail.com wrote: On 3 June 2014 16:54, Scott McGrath scmcgr...@gmail.com wrote: Where are the software options for the 8753 coming from. Agilent will not even talk about a VNA that's older than the PNA series This has been discussed on the HP/Agilent mailing list. Basically a couple of people that work at Agilent, one of whom is caes...@email.com (yes email, not gmail), will give out options for 8753 for non-commercial use. Just send him your S/N. I know he also did likewise for an older 8720 instrument (I think 8720C). Although he can, he will NOT do it for PNAs. That is one advantage of getting a used 8753/8720 over a used PNA! Agilent offered to repair my 8720D a couple of years ago, and managed to give me a quote via email as it was abundantly obvious what the problem was - a damaged thread on a test port connector. The only problem was they wanted to change the whole coupler, so it was going to cost the US equivalent of around $5000. A mate of mine sorted out the nick on the thread with a needle file!!! Dave ___ 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] VNA design
The 8410 is what I started on. Still have the hp 85 automation manuals program listings and tapes.And the hp ad converter used to convert plotter output lines to GPIB readable data the 8410 allowed one to really UNDERSTAND the network analysis process at a very basic level. If you can find a system it is a excellent platform to learn on That being said the most valuable part of any network analyzer are the calibration and verification kits Where are the software options for the 8753 coming from. Agilent will not even talk about a VNA that's older than the PNA series Sent from my iPhone On Jun 2, 2014, at 6:18 PM, Alexander Pummer alex...@ieee.org wrote: Although I used to work for one of the competitor, I still do have a complete working 8410, Rick is right, it is a very nice teaching tool 73 KJ6UHN On 6/2/2014 2:36 PM, Richard (Rick) Karlquist wrote: On 6/2/2014 12:41 PM, Brooke Clarke wrote: Hi: I started with the HP 8410 and added an external computer. Since it can be used manually I think it's an excellent way to learn about VNAs. http://www.prc68.com/I/MWTE.shtml#NA For my last 8 years at Agilent before retiring in March, I was doing advanced RD on network analyzers. The newer guys coming up didn't have an intuitive understanding of network analyzer architectures like I did. I started using the 8410 back in 1973 before I even worked for HP. Because of the modular design, it was like a teaching tool that forced you to understand what was going on. When I mentored the young guys, I would explain to them a lot of principles based on the 8410. Modern network analyzers are too automatic. The 8410 puts modern VNA's into perspective. BTW, I used to sit next to Dick Lee, who was a member of the 8410 design team in 1963 at the dawn of the golden age of microwave instruments based on YIG tuned oscillators and step recovery diode samplers. As you noted, the architecture was built around the YIG tuned oscillator and certain things were done that way they were because of that. Rick Karlquist N6RK ___ 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] VNA design
On 3 June 2014 16:54, Scott McGrath scmcgr...@gmail.com wrote: Where are the software options for the 8753 coming from. Agilent will not even talk about a VNA that's older than the PNA series This has been discussed on the HP/Agilent mailing list. Basically a couple of people that work at Agilent, one of whom is caes...@email.com (yes email, not gmail), will give out options for 8753 for non-commercial use. Just send him your S/N. I know he also did likewise for an older 8720 instrument (I think 8720C). Although he can, he will NOT do it for PNAs. That is one advantage of getting a used 8753/8720 over a used PNA! Agilent offered to repair my 8720D a couple of years ago, and managed to give me a quote via email as it was abundantly obvious what the problem was - a damaged thread on a test port connector. The only problem was they wanted to change the whole coupler, so it was going to cost the US equivalent of around $5000. A mate of mine sorted out the nick on the thread with a needle file!!! Dave ___ 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] VNA design
Boy this is not time-nuts and I had been deleting the thread. No problem with the thread. Just I have HP VNAs. Yes including what caught my eye the 8410 that Scott spoke of and its still operational. Heavy as heck like real equipment should be. I am curious I sort of thought the 8410 was pre micro processor and yet some how the HP85 hooked up to it?? I have the 8757 also so. Great comment by Dave on the fact that someone will give out some of the old options. Now I have to figure out what on earth that might actually mean. Regards Paul WB8TSL On Tue, Jun 3, 2014 at 12:57 PM, Dr. David Kirkby drkir...@gmail.com wrote: On 3 June 2014 16:54, Scott McGrath scmcgr...@gmail.com wrote: Where are the software options for the 8753 coming from. Agilent will not even talk about a VNA that's older than the PNA series This has been discussed on the HP/Agilent mailing list. Basically a couple of people that work at Agilent, one of whom is caes...@email.com (yes email, not gmail), will give out options for 8753 for non-commercial use. Just send him your S/N. I know he also did likewise for an older 8720 instrument (I think 8720C). Although he can, he will NOT do it for PNAs. That is one advantage of getting a used 8753/8720 over a used PNA! Agilent offered to repair my 8720D a couple of years ago, and managed to give me a quote via email as it was abundantly obvious what the problem was - a damaged thread on a test port connector. The only problem was they wanted to change the whole coupler, so it was going to cost the US equivalent of around $5000. A mate of mine sorted out the nick on the thread with a needle file!!! Dave ___ 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] VNA design
On 3 June 2014 19:22, paul swed paulsw...@gmail.com wrote: Great comment by Dave on the fact that someone will give out some of the old options. Now I have to figure out what on earth that might actually mean. Regards Paul WB8TSL There are a few options for those VNAs. These are basically generic, but check your manual for more details. 1) Option 006, on an 8753B or later, allows the instrument to work to 6 GHz. It basically lets the receiver tune to 6 GHz, but the internal source still only goes to 3 GHz. So you need an S-parameter test set with a doubler to get to 6 GHz. But there is no harm in having the option, irrespective of whether you have a 6 GHz test set. 2) Option 010 is the time domain. It converts the frequency domain data to the time domain via an inverse FFT. Then you can put a gate around some stuff in the time domain and transform that back to the frequency domain. A nice option to have, and very expensive on new instruments. 3) Option 002 allow the instrument to work on harmonics. I'm not sure how useful that actually is - I think it was mainly for internal use at HP, and is not of great use, but if you can get the option, you might as well. 4) Old 8720 series instruments had a tuning step of 100 kHz. There is an option to make that 1 Hz. How the HP got away with selling a VNA where the step size was 100 kHz I will never know, but they did. There are other options for the instruments - the most time-nut related is the high stability oscillator. That is option 1D5 on my instrument (8720D). I don't know how easy it is to add the hardware to an 8753 - I suspect it is just one of the standard 10811A or similar oscillators. If you do that, it would seem sensible to get the instrument to report it has the option, even though it wont actually effect the performance. It would affect the resale value, and would mean Agilent would calibrate it properly if sent it for cal. When my 8720D was sent it for calibration, the accuracy of both the standard and the high stability oscillator was checked. Both were in spec. I suspect they would not check the high stability one unless the instrument reported it had that option fitted. BTW, Agilent will still calibrate 8753s, and when I got my 8720D done, it was not that expensive. I guess it is all relative, but the 8720D is quite an expensive instrument, and I use it professionally, so it is worth getting calibrated - unlike 99% of the other stuff I have. Dave ___ 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] VNA design
My bad the 8757 is only a scalar not a vna like the 8410 and 8505. Thought I went astray and had to go look after you mentioned the options. Regards Paul. WB8TSL On Tue, Jun 3, 2014 at 3:32 PM, Dr. David Kirkby drkir...@gmail.com wrote: On 3 June 2014 19:22, paul swed paulsw...@gmail.com wrote: Great comment by Dave on the fact that someone will give out some of the old options. Now I have to figure out what on earth that might actually mean. Regards Paul WB8TSL There are a few options for those VNAs. These are basically generic, but check your manual for more details. 1) Option 006, on an 8753B or later, allows the instrument to work to 6 GHz. It basically lets the receiver tune to 6 GHz, but the internal source still only goes to 3 GHz. So you need an S-parameter test set with a doubler to get to 6 GHz. But there is no harm in having the option, irrespective of whether you have a 6 GHz test set. 2) Option 010 is the time domain. It converts the frequency domain data to the time domain via an inverse FFT. Then you can put a gate around some stuff in the time domain and transform that back to the frequency domain. A nice option to have, and very expensive on new instruments. 3) Option 002 allow the instrument to work on harmonics. I'm not sure how useful that actually is - I think it was mainly for internal use at HP, and is not of great use, but if you can get the option, you might as well. 4) Old 8720 series instruments had a tuning step of 100 kHz. There is an option to make that 1 Hz. How the HP got away with selling a VNA where the step size was 100 kHz I will never know, but they did. There are other options for the instruments - the most time-nut related is the high stability oscillator. That is option 1D5 on my instrument (8720D). I don't know how easy it is to add the hardware to an 8753 - I suspect it is just one of the standard 10811A or similar oscillators. If you do that, it would seem sensible to get the instrument to report it has the option, even though it wont actually effect the performance. It would affect the resale value, and would mean Agilent would calibrate it properly if sent it for cal. When my 8720D was sent it for calibration, the accuracy of both the standard and the high stability oscillator was checked. Both were in spec. I suspect they would not check the high stability one unless the instrument reported it had that option fitted. BTW, Agilent will still calibrate 8753s, and when I got my 8720D done, it was not that expensive. I guess it is all relative, but the 8720D is quite an expensive instrument, and I use it professionally, so it is worth getting calibrated - unlike 99% of the other stuff I have. Dave ___ 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] VNA design
There is a popular DIY VNA designed by N2PK, boards are available from a fellow in Ontario Canada, a quick google search should find the information for you. Also, Sam Wettlerlin has published much on his web site with respect to Scotty's Spectrum Analyzer project, VNA, return loss bridges, etc. http://www.wetterlin.org/sam/ Also, there is an interesting project called the Poor Hams Scalar Network Analyzer (PHSNA) which may be of interest. There is an active Yahoo group. All that is missing is a phase detector to make it a simple VNA. Based on Arduino and the inexpensive AD9850/AD9851 DDS boards from Asia. I'd like a VNA too but I am starting small with the PHSNA and will build from there. My needs are not that great, just as a learning tool and to support my ham radio tinkering. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali Sent: June-02-14 10:43 AM To: time-nuts@febo.com Subject: [time-nuts] VNA design Hi, I know this is not exactly a time-nut question, but i guess this is the best place i know to ask about this stuff. I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. Well, my problem now is, that i don't know how to build a VNA. Yes, i understand the basic principle. I can come up with a design that should work. But i have no clue about any problems or difficulties in building these devices. Ie it's very likely that i fall into a dozen traps when i try to build one. I tried to get information on how to build a VNA, or what kind of trouble people had operating one, but beside the VNA book[1] Rick mentioned a couple of months ago and ko4bb's site (thanks man! your manual collection is a gold mine!), my searches came out blank. As i'm quite sure that there is information of that kind out there, i would like to ask whether someone could point me to some documents, webpages, books, papers, etc that would show me the detailed design of VNA, the problems people had with some designs or anything else that would be of interest in such an endavor. Also, any good resource on how to build a directional coupler that does 10-3000MHz without going to exotic materials would be much appreciated. All papers i found deal mostly with stuff above 5GHz. Seems like low frequency couplers are considered a solved problem. Attila Kinali [1] Handbook of Microwave Component Measurements: with Advanced VNA Techniques by Dunsmore, 2012 -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ 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. This electronic message, as well as any transmitted files included in the electronic message, may contain privileged or confidential information and is intended solely for the use of the individual(s) or entity to which it is addressed. If you have received this electronic message in error please notify the sender immediately and delete the electronic message. Any unauthorized copying, disclosure or distribution of the electronic message is strictly forbidden. NAV CANADA accepts no liability for any damage caused by any virus and/or other malicious code transmitted by this electronic communication. Le présent message électronique et tout fichier qui peut y être joint peuvent contenir des renseignements privilégiés ou confidentiels destinés à l’usage exclusif des personnes ou des organismes à qui ils s’adressent. Si vous avez reçu ce message électronique par erreur, veuillez en informer l’expéditeur immédiatement et supprimez le. Toute reproduction, divulgation ou distribution du présent message électronique est strictement interdite. NAV CANADA n’assume aucune responsabilité en cas de dommage causé par tout virus ou autre programme malveillant transmis par ce message électronique. ___ 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] VNA design
Attila You might want to look at the N2PK and DG8SAQ vector network analyzer projects there are also some commercial USB based 'personal' network analyzers out there starting about 6K As for directional couplers. I would suggest buying vs building Mini Circuits has a line of high quality inexpensive couplers in both coaxial and surface mount at price points affordable for individuals these really are a solved problem. You could of course build waveguide based Couplers at lower frequencies they would be physically large but easy to construct if you have access to machine tools Most commercial VNAs are still in the boat anchor class for size and weight at the office we have a RS 40 Ghz 4 port VNA and it's still huge and heavy along with a fleet of agilents Sent from my iPad On Jun 2, 2014, at 10:43 AM, Attila Kinali att...@kinali.ch wrote: Hi, I know this is not exactly a time-nut question, but i guess this is the best place i know to ask about this stuff. I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. Well, my problem now is, that i don't know how to build a VNA. Yes, i understand the basic principle. I can come up with a design that should work. But i have no clue about any problems or difficulties in building these devices. Ie it's very likely that i fall into a dozen traps when i try to build one. I tried to get information on how to build a VNA, or what kind of trouble people had operating one, but beside the VNA book[1] Rick mentioned a couple of months ago and ko4bb's site (thanks man! your manual collection is a gold mine!), my searches came out blank. As i'm quite sure that there is information of that kind out there, i would like to ask whether someone could point me to some documents, webpages, books, papers, etc that would show me the detailed design of VNA, the problems people had with some designs or anything else that would be of interest in such an endavor. Also, any good resource on how to build a directional coupler that does 10-3000MHz without going to exotic materials would be much appreciated. All papers i found deal mostly with stuff above 5GHz. Seems like low frequency couplers are considered a solved problem. Attila Kinali [1] Handbook of Microwave Component Measurements: with Advanced VNA Techniques by Dunsmore, 2012 -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ 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] VNA design
Today you can do most of the processing in software. All you need is A/D and D/A converters that can handle the required bandwidth and get the raw numbers into the computer. Look up SDR type radios and search on the combination of SDR and VNA and you'll find a few. Then with the same hardware you have a VNA, spectrum analyzer, oscilloscope, low power transceiver and so on. This idea is somewhat easy through HF. On Mon, Jun 2, 2014 at 7:43 AM, Attila Kinali att...@kinali.ch wrote: Hi, I know this is not exactly a time-nut question, but i guess this is the best place i know to ask about this stuff. I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. -- 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] VNA design
There's a DIY project to build a spectrum analyzer at http://scottyspectrumanalyzer.com . Since it's modular, one version of the project is to add a couple of modules that change it into a network analyzer. If you search ebay for directional couplers, I can almost guarantee that you will find what you want at a reasonable price. Ed On 6/2/2014 8:43 AM, Attila Kinali wrote: Hi, I know this is not exactly a time-nut question, but i guess this is the best place i know to ask about this stuff. I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. Well, my problem now is, that i don't know how to build a VNA. Yes, i understand the basic principle. I can come up with a design that should work. But i have no clue about any problems or difficulties in building these devices. Ie it's very likely that i fall into a dozen traps when i try to build one. I tried to get information on how to build a VNA, or what kind of trouble people had operating one, but beside the VNA book[1] Rick mentioned a couple of months ago and ko4bb's site (thanks man! your manual collection is a gold mine!), my searches came out blank. As i'm quite sure that there is information of that kind out there, i would like to ask whether someone could point me to some documents, webpages, books, papers, etc that would show me the detailed design of VNA, the problems people had with some designs or anything else that would be of interest in such an endavor. Also, any good resource on how to build a directional coupler that does 10-3000MHz without going to exotic materials would be much appreciated. All papers i found deal mostly with stuff above 5GHz. Seems like low frequency couplers are considered a solved problem. Attila Kinali [1] Handbook of Microwave Component Measurements: with Advanced VNA Techniques by Dunsmore, 2012 ___ 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] VNA design
On 6/2/2014 7:43 AM, Attila Kinali wrote: Also, any good resource on how to build a directional coupler that does 10-3000MHz without going to exotic materials would be much I once had the opportunity to discuss directional couplers with Julius Botka, then with HP/Agilent. Specifically, a true directional coupler he designed that approached the range of 10-3000 MHz. IMHO, Botka was one of the greatest experts of all time in this area. It took extreme attention to detail to get it to work. It didn't so much involve exotic materials, but rather expertise. Don't try this at home kids. Julius said that he designed it before the era of cheap calibration. Now that everyone has calibration, you don't need a good directional coupler. You can get away with a MiniCircuits coupler. But in fact it is even easier to just use a resistive bridge. Four ordinary resistors will easily go to 3 GHz. Use a differential amplifier at the output. Lots of info on this in the literature. Another way to make in effect a directional coupler is to use a 180 degree hybrid. I also had the opportunity to study Alan Podell's amazing designs and even have discussions with him. I dissected one of his 10-3000 MHz hybrids. (Originally made by Anzac, now available from Macom Technology for about 5 Benjamins). Don't even think about trying this at home. BTW, you didn't mention software, but that's a big part of the job. Rick Karlquist N6RK ___ 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] VNA design
On Mon, 2 Jun 2014 11:09:55 -0400 Scott McGrath scmcgr...@gmail.com wrote: You might want to look at the N2PK and DG8SAQ vector network analyzer projects there are also some commercial USB based 'personal' network analyzers out there starting about 6K I've seen both and looked at their implementation. Especially DG8SAQ is conceptually quite interesting IMHO (using the harmonics of an DDS chip). But i'd like to get at least to 1.6GHz (think GPS) Otherwise i would have ordered one of them already. (Side note: i am not sure whether i will get to building a VNA. I am currently just playing with the idea and try to learn about their function as much as possible) As for directional couplers. I would suggest buying vs building Mini Circuits has a line of high quality inexpensive couplers in both coaxial and surface mount at price points affordable for individuals these really are a solved problem. Yes. But their SMD are only 3 port, ie the isolated port is internally terminated. Which in turn means, i'd need to put two of those in to get both transmitted and reflected wave. You could of course build waveguide based Couplers at lower frequencies they would be physically large but easy to construct if you have access to machine tools I think all the Minicircuit ones are build using transformers. I cannot think of any other way to get such a large bandwith in these small dimensions otherwise. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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] VNA design
The design of an VNA is an interesting thing. It requires quite high focus on good RF practices and screening. In the range 0-3GHz there is no low cost devices avaible, not counting the copper mountain tech boxes ( http://www.coppermountaintech.com/ ). Up to 1.3GHz there is the DG8SAQ VNWA avaible from sdrkits, these can also be used with mixers to extend the max frequency. The VNWA is an 2 detector VNA that needs an S-parameter testset in order to get all the 4 S-parameters. An homebrew alternative would be fun to do, but its a lot of work, both in getting reproduceable data from the hardware and in programming. Building somthing that is connected to the PC simplifies things a lot. Couplers and detectors are not the hardest thing to make, some small SMD resistors, an balanced amplifier - detector and things should work to 6GHz or higher with some care in the layout. Signal generation is perhaps the hardest part, there is AFAIK no single solution working from LF to high UHF, one cool alternative is to build an generator with an YIG and mixing down, but that requires a lot of work to get stable over the range 0-3GHz. In addition you need to keep the signal from the generator out of the detector in order to keep the dynamic range high. If you are building your own VNA, I would build it with 4 detectors and the posibility to re-configure those. It opens for several of the more advanced calibration methods and eliminates some of the errors in the VNA. If I were to build something, I think I would base it on the N2PK design, as there is documentation and programs avaible that makes for some part of the work. There are some IC's avaible that do the detection of the power levels, AD8302 comes to mind, the common denominator for these are that they don't solve for the phase sign, and thereby are not true vector. In addition, those I have tested don't behave to well with As an alternative, the HP8410 series are avaible here in the EU, sometimes quite cheap, if you can wait a bit. Mine is mostly used at microwaves, with some external mixers and testsets. If you are low on cash, this may be the best approach, but it requires some work. The accuracy of the VNA is determined by the calkit used to calibrate it. There is no way around obtaining an good calkit, learning how to use it without destroying it, and do repeatable calibrations. The calkit is the single most important part of the VNA. Do use an calkit for the connectors you are going to measure, don't add adaptors or worse, coaxial cable after the calibration plane. The book by Joel Dunsmore is excelent, highly reccomended if you are doing or interested in VNA measurments. BR. Thomas. 2014-06-02 16:43 GMT+02:00 Attila Kinali att...@kinali.ch: Hi, I know this is not exactly a time-nut question, but i guess this is the best place i know to ask about this stuff. I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. Well, my problem now is, that i don't know how to build a VNA. Yes, i understand the basic principle. I can come up with a design that should work. But i have no clue about any problems or difficulties in building these devices. Ie it's very likely that i fall into a dozen traps when i try to build one. I tried to get information on how to build a VNA, or what kind of trouble people had operating one, but beside the VNA book[1] Rick mentioned a couple of months ago and ko4bb's site (thanks man! your manual collection is a gold mine!), my searches came out blank. As i'm quite sure that there is information of that kind out there, i would like to ask whether someone could point me to some documents, webpages, books, papers, etc that would show me the detailed design of VNA, the problems people had with some designs or anything else that would be of interest in such an endavor. Also, any good resource on how to build a directional coupler that does 10-3000MHz without going to exotic materials would be much appreciated. All papers i found deal mostly with stuff above 5GHz. Seems like low frequency couplers are considered a solved problem. Attila Kinali [1] Handbook of Microwave Component Measurements: with Advanced VNA Techniques by Dunsmore, 2012 -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___
Re: [time-nuts] VNA design
On Mon, 02 Jun 2014 09:46:38 -0600 Ed Palmer ed_pal...@sasktel.net wrote: There's a DIY project to build a spectrum analyzer at http://scottyspectrumanalyzer.com . Since it's modular, one version of the project is to add a couple of modules that change it into a network analyzer. That looks very interesting. Thanks for the link! If you search ebay for directional couplers, I can almost guarantee that you will find what you want at a reasonable price. Yes. But if i ever build something, it should be reproducible for others as well. Thus i don't want to rely on stuff from ebay which can suddenly disapear. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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] VNA design
On Mon, 2 Jun 2014 09:01:37 -0700 Chris Albertson albertson.ch...@gmail.com wrote: Today you can do most of the processing in software. All you need is A/D and D/A converters that can handle the required bandwidth and get the raw numbers into the computer. Look up SDR type radios and search on the combination of SDR and VNA and you'll find a few. Then with the same hardware you have a VNA, spectrum analyzer, oscilloscope, low power transceiver and so on. This idea is somewhat easy through HF. That's actually the base idea. Get some wide range synthesizer (eg like HMC832LP6GE or LTC6946) for the test signal and one for the detection part. Mix down the received signal and use some ADC to move into digital domain. There preprocess the data in an FPGA (data reduction) and do all difficult stuff in the PC. Yes, it all sounds so easy. But i'm sure there must be some trap in there, which i cannot see yet. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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] VNA design
On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote: I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. There are a few designs around. The early version of the VNWA was described in QEX. There is the N2PK design too. The latter has a limited frequency range, but a high dynamic range. All modern professional systems with two ports use 4 receivers. Earlier designs use 3 receivers which is not good for TRL calibration. I think it would be a huge task. I think that the main issue would be the software. I have been considering adding the unknown thru calibration method to my HP 8720D. That in itself would be quite a task, but writing all the software for a VNA would be a huge task. I thought TAPR had a similar project but I don't recall it producing anything close to workable. BTW the software options for the HP 8753's are now easily available, so if you do buy an 8753 (probably the best choice), don't worry about what software options it has. I would really like to see an open hardware and software VNA, but it would be a lot of work. If you do it, think about having 3 or 4 ports with independent sources for optimal balanced measurements. I don't think that there's much point producing a design with just a TR test set. Dave. ___ 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] VNA design
On Mon, 02 Jun 2014 09:35:41 -0700 Richard (Rick) Karlquist rich...@karlquist.com wrote: Julius said that he designed it before the era of cheap calibration. Now that everyone has calibration, you don't need a good directional coupler. You can get away with a MiniCircuits coupler. How about impedance matching issues? Can those be calibrated away? But in fact it is even easier to just use a resistive bridge. Four ordinary resistors will easily go to 3 GHz. Use a differential amplifier at the output. Lots of info on this in the literature. I somewhat fear that the parasitics of resistors will give me garbage when going to 1GHz. Maybe i should look into those and calculate how much performance they would cost. Another way to make in effect a directional coupler is to use a 180 degree hybrid. My understanding is, that those are rather narrow band. Those i've seen were at most one octave in range. Don't even think about trying this at home. You mention that for both Podell's and Botkas design. May i ask what the reason is? Why do you think it cannot be done at home? Also, i quickly tried to search for both Botka and Podell. While Podell gives a couple of matches on ieeexplore, Botka comes back almost empty. Any hints to for finding references to their work? BTW, you didn't mention software, but that's a big part of the job. Because i have not had a look into that yet. My guess is that phase detection of a known frequency (i ignore multi-tone detection due to harmonics for the moment) is known and should be easy. So the big part of the softare is getting thins into the PC and doing a good job of presenting the data, ie GUI stuff. And GUI is, once you have a graphical design, just implementation work. Please correct me if i'm mistaken. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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] VNA design
On 2 Jun 2014 17:33, Ed Palmer ed_pal...@sasktel.net wrote: There's a DIY project to build a spectrum analyzer at http://scottyspectrumanalyzer.com . Since it's modular, one version of the project is to add a couple of modules that change it into a network analyzer. But I think a VNA is an order of magnitude more complex than a SA - pun intended! The software is probably where the biggest work is. A modular design for a VNA would be interesting, as different sources, couplers etc could be used depending on frequency range. Dave. ___ 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] VNA design
On 2 Jun 2014 18:14, Thomas S. Knutsen la3...@gmail.com wrote: The design of an VNA is an interesting thing. It requires quite high focus on good RF practices and screening. In the range 0-3GHz there is no low cost devices avaible, not counting the copper mountain tech boxes ( http://www.coppermountaintech.com/ ). Up to 1.3GHz there is the DG8SAQ VNWA avaible from sdrkits, these can also be used with mixers to extend the max frequency. The VNWA is an 2 detector VNA that needs an S-parameter testset in order to get all the 4 S-parameters. An homebrew alternative would be fun to do, but its a lot of work, both in getting reproduceable data from the hardware and in programming. Building somthing that is connected to the PC simplifies things a lot. Couplers and detectors are not the hardest thing to make, some small SMD resistors, an balanced amplifier - detector and things should work to 6GHz or higher with some care in the layout. Signal generation is perhaps the hardest part, there is AFAIK no single solution working from LF to high UHF, one cool alternative is to build an generator with an YIG and mixing down, but that requires a lot of work to get stable over the range 0-3GHz. In addition you need to keep the signal from the generator out of the detector in order to keep the dynamic range high. If you are building your own VNA, I would build it with 4 detectors and the posibility to re-configure those. It opens for several of the more advanced calibration methods and eliminates some of the errors in the VNA. If I were to build something, I think I would base it on the N2PK design, as there is documentation and programs avaible that makes for some part of the work. There are some IC's avaible that do the detection of the power levels, AD8302 comes to mind, the common denominator for these are that they don't solve for the phase sign, and thereby are not true vector. In addition, those I have tested don't behave to well with As an alternative, the HP8410 series are avaible here in the EU, sometimes quite cheap I assume you mean 8510. The accuracy of the VNA is determined by the calkit used to calibrate it. There is no way around obtaining an good calkit, learning how to use it without destroying it, and do repeatable calibrations. The calkit is the single most important part of the VNA. Do use an calkit for the connectors you are going to measure, don't add adaptors or worse, coaxial cable after the calibration plane. I had at one point an HP 8753A (3 GHz) VNA with a full S-parameter test set. It cost me about 50% of what my HP 85054B 18 GHz N calibration kit cost me and I think I got the 85054B cheap at about $3800. I do sell low cost calibration kits for N, SMA and X-band waveguide. Dave ___ 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] VNA design
One which is, IMHO, good value for money is this one. I've been very pleased with mine. http://sdr-kits.net/VNWA3_Description.html Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] VNA design
Those interested might look at RedPitaya.com for a new piece of hardware that might be used. Less than $500 without a box Don Dr. David Kirkby On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote: I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. There are a few designs around. The early version of the VNWA was described in QEX. There is the N2PK design too. The latter has a limited frequency range, but a high dynamic range. All modern professional systems with two ports use 4 receivers. Earlier designs use 3 receivers which is not good for TRL calibration. I think it would be a huge task. I think that the main issue would be the software. I have been considering adding the unknown thru calibration method to my HP 8720D. That in itself would be quite a task, but writing all the software for a VNA would be a huge task. I thought TAPR had a similar project but I don't recall it producing anything close to workable. BTW the software options for the HP 8753's are now easily available, so if you do buy an 8753 (probably the best choice), don't worry about what software options it has. I would really like to see an open hardware and software VNA, but it would be a lot of work. If you do it, think about having 3 or 4 ports with independent sources for optimal balanced measurements. I don't think that there's much point producing a design with just a TR test set. Dave. ___ 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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ 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] VNA design
Also, a convenient signal source with built-in attenuator: http://www.rf-consultant.com/calibrated-signal-generator/ Don Dr. David Kirkby On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote: I recently got introduced into the usefullness of a VNA. But these things are horribly expensive for home use, even if bought from ebay (before you say anything, remember i live in europe, where every boat anchor hast to travel a long way). But given that most of the designs that are on ebay are from the 80s and early 90s, i thought that with todays ICs it should be easy to come up with a design that does the same thing but can be build on a kitchen table. There are a few designs around. The early version of the VNWA was described in QEX. There is the N2PK design too. The latter has a limited frequency range, but a high dynamic range. All modern professional systems with two ports use 4 receivers. Earlier designs use 3 receivers which is not good for TRL calibration. I think it would be a huge task. I think that the main issue would be the software. I have been considering adding the unknown thru calibration method to my HP 8720D. That in itself would be quite a task, but writing all the software for a VNA would be a huge task. I thought TAPR had a similar project but I don't recall it producing anything close to workable. BTW the software options for the HP 8753's are now easily available, so if you do buy an 8753 (probably the best choice), don't worry about what software options it has. I would really like to see an open hardware and software VNA, but it would be a lot of work. If you do it, think about having 3 or 4 ports with independent sources for optimal balanced measurements. I don't think that there's much point producing a design with just a TR test set. Dave. ___ 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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ 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] VNA design
I do not wanted to discourage any body, but building the hardware of a network analyzer is not a simple task, and requires substantial instrumentation, software could solve hardware problems to certain limit only 73 KJ6UHN On 6/2/2014 10:38 AM, Dr. David Kirkby wrote: On 2 Jun 2014 17:33, Ed Palmer ed_pal...@sasktel.net wrote: There's a DIY project to build a spectrum analyzer at http://scottyspectrumanalyzer.com . Since it's modular, one version of the project is to add a couple of modules that change it into a network analyzer. But I think a VNA is an order of magnitude more complex than a SA - pun intended! The software is probably where the biggest work is. A modular design for a VNA would be interesting, as different sources, couplers etc could be used depending on frequency range. Dave. ___ 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] VNA design
Hi: I started with the HP 8410 and added an external computer. Since it can be used manually I think it's an excellent way to learn about VNAs. http://www.prc68.com/I/MWTE.shtml#NA It turns out that when automating a VNA the same frequency is measured many times during cal and device testing. If the frequency is not exactly the same errors are introduced. The early systems used sweep generators and harmonic locking which might lock to different harmonic numbers thus causing errors. Later systems used EIP frequency counters to phase lock the sweepers to minimize that problem and the newest systems use frequency synthesizers with good reference oscillators (Time Nuts content). Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html ___ 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] VNA design
On 2 Jun 2014 19:07, Alexander Pummer alex...@ieee.org wrote: I do not wanted to discourage any body, but building the hardware of a network analyzer is not a simple task, and requires substantial instrumentation, software could solve hardware problems to certain limit only 73 KJ6UHN VERY TRUE The larger the hardware errors, the larger the errors that need to removed so the accuracy of measurements suffer with the slightest change in temperature. Adapters with a poor return loss BEFORE the calibration plane can still cause problems with stability of measurements. Despite error correction, it is not uncommon to do things like improve the match at test ports with attenuators. I think it would be unwise to embark on designing a VNA unless one has at least used one first. I don't think designing a VNA is the best way to get one. Perhaps after buying one (8510 or 8753 is probably best) then designing one is likely to be more productive. Dave. ___ 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] VNA design
On 6/2/2014 12:41 PM, Brooke Clarke wrote: Hi: I started with the HP 8410 and added an external computer. Since it can be used manually I think it's an excellent way to learn about VNAs. http://www.prc68.com/I/MWTE.shtml#NA For my last 8 years at Agilent before retiring in March, I was doing advanced RD on network analyzers. The newer guys coming up didn't have an intuitive understanding of network analyzer architectures like I did. I started using the 8410 back in 1973 before I even worked for HP. Because of the modular design, it was like a teaching tool that forced you to understand what was going on. When I mentored the young guys, I would explain to them a lot of principles based on the 8410. Modern network analyzers are too automatic. The 8410 puts modern VNA's into perspective. BTW, I used to sit next to Dick Lee, who was a member of the 8410 design team in 1963 at the dawn of the golden age of microwave instruments based on YIG tuned oscillators and step recovery diode samplers. As you noted, the architecture was built around the YIG tuned oscillator and certain things were done that way they were because of that. Rick Karlquist N6RK ___ 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] VNA design
Although I used to work for one of the competitor, I still do have a complete working 8410, Rick is right, it is a very nice teaching tool 73 KJ6UHN On 6/2/2014 2:36 PM, Richard (Rick) Karlquist wrote: On 6/2/2014 12:41 PM, Brooke Clarke wrote: Hi: I started with the HP 8410 and added an external computer. Since it can be used manually I think it's an excellent way to learn about VNAs. http://www.prc68.com/I/MWTE.shtml#NA For my last 8 years at Agilent before retiring in March, I was doing advanced RD on network analyzers. The newer guys coming up didn't have an intuitive understanding of network analyzer architectures like I did. I started using the 8410 back in 1973 before I even worked for HP. Because of the modular design, it was like a teaching tool that forced you to understand what was going on. When I mentored the young guys, I would explain to them a lot of principles based on the 8410. Modern network analyzers are too automatic. The 8410 puts modern VNA's into perspective. BTW, I used to sit next to Dick Lee, who was a member of the 8410 design team in 1963 at the dawn of the golden age of microwave instruments based on YIG tuned oscillators and step recovery diode samplers. As you noted, the architecture was built around the YIG tuned oscillator and certain things were done that way they were because of that. Rick Karlquist N6RK ___ 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] VNA design
Hi, I have an HP 8412B and an HP 8413A, which go with the HP 8410, for $ 30.00 ( maybe less) each plus actual shipping. They look good but I have no way to test then since I have no mainframe. Contact offline if interested. I can email pictures. They will be at the Huntsville Hamfest later this summer. Bill Reed ree...@otelco.net -Original Message- From: Alexander Pummer Sent: Monday, June 02, 2014 5:18 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] VNA design Although I used to work for one of the competitor, I still do have a complete working 8410, Rick is right, it is a very nice teaching tool 73 KJ6UHN On 6/2/2014 2:36 PM, Richard (Rick) Karlquist wrote: On 6/2/2014 12:41 PM, Brooke Clarke wrote: Hi: I started with the HP 8410 and added an external computer. Since it can be used manually I think it's an excellent way to learn about VNAs. http://www.prc68.com/I/MWTE.shtml#NA For my last 8 years at Agilent before retiring in March, I was doing advanced RD on network analyzers. The newer guys coming up didn't have an intuitive understanding of network analyzer architectures like I did. I started using the 8410 back in 1973 before I even worked for HP. Because of the modular design, it was like a teaching tool that forced you to understand what was going on. When I mentored the young guys, I would explain to them a lot of principles based on the 8410. Modern network analyzers are too automatic. The 8410 puts modern VNA's into perspective. BTW, I used to sit next to Dick Lee, who was a member of the 8410 design team in 1963 at the dawn of the golden age of microwave instruments based on YIG tuned oscillators and step recovery diode samplers. As you noted, the architecture was built around the YIG tuned oscillator and certain things were done that way they were because of that. Rick Karlquist N6RK ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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.
