F3560R Mystery YIG - Page 1
Forum section: electronics / testgear

author: jjoonathan
author_rank: Frequent Contributor
timestamp: December 27, 2021, 10:40:28 pm
content: So a while back I saw one of those "Steel Cube" style Ferretec YIG filters on ebay with the part number F3560R. I think I've heard that these sometimes show up in R&S and Anritsu kit, but I'm primarily experienced in Advantest and HP so I don't really know (that's partially why I'm posting -- I'm fishing for information). There's a Ferretec part number guide but it didn't seem to give reasonable results, except that "R" probably means "custom job." In any case, the YIG had 1.85mm connectors on it, and I'm a sucker for 1.85mm connectors, so I bought. It didn't exactly break the bank, but I paid enough to make this a spicy betI swept it on my 8510 VNA and found that its passband started to kick in at about 3.5GHz and remained strong through 26.5GHz, which was the limit of my 83621 source at the time. "3.5" is familiar -- could it be the "35" from the part number? Could "60" mean 60GHz? So far, so good. Exciting!Some time later I found a doubler module at a small off-ebay shop in Boston and turned my 83621 into a 83651, bringing my 8510's network analysis range up to 50GHz. Of course, one of the first things I swept was the mystery YIG -- and its response remained strong all the way through 50GHz! Very cool!Fast forward to Christmas -- I got myself some Marki modules that finally let me do scalar analysis above 50GHz. Down the road, they'll also play a key role in the spectrum analyzer I hope to build around this YIG, but one thing at a time. I've finished characterizing the mystery YTF and here are the results! Long story short: F3560R is picture perfect to 50GHz, starts to saturate a bit at 60GHz, and above that it gets leaky and hot. Presumably this has to do with magnetic saturation of some kind, but I'm not an expert in ferrites so I can only speculate. Still, hopefully these measurements help calibrate expectations if anyone else is thinking about buying one!Github:https://github.com/jjoonathan/F3560R-YIG-FilterS21:https://jjoonathan.github.io/sweep1.htmlPS -- for those of you who are concerned about my connectors, don't worry, the ad-hoc "scalar analyzer" was supported on both ends by machinist jacks.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: December 31, 2021, 08:37:10 pm
content: BWAHAHAH just found this in the HP Journal. There's nothing new under the sun, is there?

author: 0culus
author_rank: Super Contributor
timestamp: December 31, 2021, 09:12:14 pm
content: Neat stuff. You should share it up in the RF forum, because I think some of the folks who read that don't really read down here.Related: the doubler module you speak of, was this an internal modification to your microwave source, then?

author: jjoonathan
author_rank: Frequent Contributor
timestamp: December 31, 2021, 09:37:49 pm
content: Yeah, I sort of assumed that most of the audience was shared, but I don't actually know if that's true. I posted it here because I was hoping someone would come in and say "I know that YTF! It lives in the Anritsu model? and the frequency plan doesn't use it until 5GHz due to saturation nonlinearity" or something. Incidentally, that's another thing I didn't know until I started reading up on YIGs! Evidently you shouldn't just use them as soon as S21 starts to look acceptable because they can totally do that! I haven't actually tried to replicate the effect yet, but I'll have to give it a go.As for the 8360 journey, I wrote it up here:https://photos.app.goo.gl/mqyQ7gJZpXEGeFzZ6

author: 0culus
author_rank: Super Contributor
timestamp: December 31, 2021, 11:10:14 pm
content: Quote from: jjoonathan on December 31, 2021, 09:37:49 pmI unfortunately don't know the YTF.Very cool upgrade though. My new-to-me 8510C system has the 8340B for the microwave source. Eventually, I plan to make it a 50 GHz system.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: January 01, 2022, 12:01:13 am
content: Cool! I went down the same path. Ebay alerts and patience, while I worked on my 26.5 skillsHere's a diagram of an 8360 with a screen. JPG murdered it a bit, lol, but you can see that there are two YTFs: one in the same module as the multiplier (to make a "YTM," yig tuned multiplier) and one after the amplifier. The second YTF isn't strictly necessary if you don't need the spurious performance -- the 8340s don't have a second YTF, the no-front-panel 83621 and 83631 don't have a second YTF, and some of the other microwave signal generators don't have a second YTF (at one point I believe Shahriar was looking to convert a SA preselector into a SG preselector for this very purpose --https://www.youtube.com/watch?v=AdVlSvVIGwM), but the 8360s with a screen do have a second YTF and the 83651 has a second YTF because the 50GHz doubler aggravates spurs to a point that the 8510 can't handle. I put the part number in the picture.Have fun and good luck! Be sure to ping me if you have any questions.