[LiConn] Ever heard of this brand? - Page 1
Forum section: electronics / rf-microwave

author: blueskull
author_rank: Unknown
timestamp: May 01, 2019, 01:21:31 am
content: While searching for a VNA calibration kit, I came across a low cost kit that claims to have the same performance of Keysight 85033 listed here:https://www.liconn.com/VNA_CalKit.htmlRight off the bed, I found some marketing BS on their "performance validation report", that their claim is not based on S11 of their load unit, so essentially what I get is a 20dB PAD test report done with their cal kit calibrated VNA vs 85053 cal kit calibrated VNA.Considering the reflection of a 20dB PAD can be much higher than the ideal load (which is where I spend my money on), and they never bothered to show S11 in log scale, I think the reflection of the PAD greatly overcasts the reflection of the load, so the test result means nothing for the ideality of the load.Still, the price is attractive, and I think maybe it's worth a bet.The 6GHz version is for sale at $500, which is basically 1/10 the original price, though it does not come with both male and female versions, and it does not come with a wrench.Still, $500 is favorable -- even used half set (male, female is more demanding and thus more expensive) of 85033 is $1k on eBay, so this can be a great deal.Better, it comes with individual calibration data, so presumably this one is a notch higher than the cheap Chinese ones with "PNA" brand on them ($250 range).Any thoughts? Should I risk half a grand on this thing or should I stick with a genuine Keysight 7551?My intended operating frequency is up to 6.5GHz.

author: hendorog
author_rank: Super Contributor
timestamp: May 01, 2019, 01:48:03 am
content: The S11 of a 20dB pad should theoretically be -40dB, which is better than the return loss of a low cost calibration load at 6GHz I suspect. But in reality you will be seeing the quality of the pad, connections etc as they will have worse return loss than -40dB.What matters is how close it is to the HP cal kit. But the scaling of the S11 and S22 VSWR graphs make it impossible to tell how close they are.I would say if you can get them to provide s1p files (s2p file for the thru) as well then you are good to go. That shouldn't be a big deal for them as they have stated they provide unique data for each kit, so they need to sweep all of the components anyway.Then the quality of the cal kit is unimportant as you have high quality measurements of the components. The disadvantage is that you need to use something like Metas or scikit-rf on a PC.Conversely, if you only have the model data for the components - i.e. the C0, C1, Cx - then the cal kit components do need to be high quality or else the model will not be accurate for the entire bandwidth DC- 6GHz. The advantage is you can enter the model data into the VNA and directly use the VNA UI.I'd buy it, but I'd want the measured data of the standards. Dr Kirkby provided that for me with the kit I got from him. You could be a bit cheeky and ask them to sweep it over a wider frequency range as well.

author: hendorog
author_rank: Super Contributor
timestamp: May 01, 2019, 02:16:09 am
content: Quote from: blueskull on May 01, 2019, 02:00:10 amI don't live in either place so it didn't matter a shit to me who I got mine fromBut I would ask them, I'm guessing there isn't a roaring trade in third party cal kits, so they might be eager to make a sale.

author: TheSteve
author_rank: Unknown
timestamp: May 01, 2019, 03:39:33 am
content: Can't say I've ever heard of them. Could be fine as long as they provide the data to enter into the VNA and it is good.btw if you can find an 85033D/E kit they include the same open/shorts as the 85052D 26.5 GHz kit. The loads may or may not be as good - Keysight isn't telling.A friend bought an 85033D not long ago on ebay for $500 and it was in excellent condition in the original wood box with the APC7 adapters(you don't need them but they sell easily).btw, to give you can idea of how well manufactured the Keysight kits are there is no individual performance data - each kit uses the exact same parameters.edit:I would hope the LiConn kit data matches the 85052D(as they show) as that is likely what they use as a reference to measure parameters of the kits they sell.

author: xaxaxa
author_rank: Regular Contributor
timestamp: May 01, 2019, 08:06:37 am
content: I'm still inclined to say that you should at least try the homemade cal kit shown on the hforsten VNA page. The prices of the cal kits you mentioned so far are steep given the specs, since you can easily get better than -30dB at 5GHz with the home made kit. The other thing I would comment is make sure any serious cal kit you get come with S parameter characterizations.