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.
