The LiteVNA plus my rebuttal of comments made during a recent VNA presentation.
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- Опубликовано: 16 июл 2024
- A short discussion about a recent RUclips video I had watched on the low cost VNAs as well as an introduction to the LiteVNA. The LiteVNA is latest low cost network analyzer capable of working up to 6.3GHz (slightly higher).
RSGB Tonight @ 8 - An introduction to VNAs and the NanoVNA by Alan Wolke, W2AEW
• RSGB Tonight @ 8 - An ...
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My review for the NanoVNA V2 Plus 4
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Keysight video series on amplifier stability
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Oh no! I could have sworn that I measured and observed a sine wave drive out of my V2+4 before I made that presentation!!! I need to go back and check it again! So sorry for the potential misinformation!!
Please update your post after you have checked it. For comparison, the link below shows P1 of my V2Plus4 measured on my old LeCroy Wavemaster.
www.eevblog.com/forum/rf-microwave/nanovna-custom-software/msg3909005/#msg3909005
@@joesmith-je3tq I must have only tested it above 1GHz where the output is nearly sinusoidal. Just verified as you did, that the output is indeed a squarewave with a few hundred ps rise/fall (measured on a 10GHz scope). So, the signal looks more and more sinusoidal as you go above 1GHz.
@@w2aew Is that true for the V2 you mentioned as well? No doubt it gets difficult to create anything resembling a square wave the higher up we go.
@@joesmith-je3tq I had just measured the V2plus4 (comments above). Let me check the SAA-2N (the only other V2 type that I have)... ...the SAA-2N also is a squarewave with a few-hundred ps rise/fall.
@@w2aew Let us know when you check the V2. I would expect it to have a square wave drive as well but is is best if we clear up the "potential" misinformation.
Thanks Joe. I know just enough to know that I don't know enough to ask all the right questions. That's a real problem. So I watch all of your VNA videos multiple times because you are thorough in what you're covering, accurate, and more complete in covering of the associated pertinent subject matter than anyone else I've seen on RUclips videos, period. I don't have to 'unlearn' things. I understand the care that you must have to put into creating everything from your code to your videos, and all I can say is that I appreciate your effort. I try to show that appreciation by paying attention, absorbing all I can, and thinking carefully about the rest. Your videos are the best thing on RUclips.
The inexpensive NanoVNA's, TinySA's, handheld scopes and such have imperfections, as you point out, but they have allowed me to leave 400+ pounds of HP antiques at home. And the key to using gear with imperfections is to know what those imperfections are.
Thank you very much for the complement.
John, we are BLESSED to have Joe among us. I just can't say enough how much I admire him. He takes time, a huge amount of research and effort to conceive and produce these videos... and producing a video to the standard Joe does makes it so easy to watch. Joe... a mere thank you is not enough by a mile. I am one of the "Antenna Analyser Jockeys" and a lot of your stuff goes over my head but that does not mean that I am not immensly grateful for your sharing of knowlege here, coupled with the brutal amount of time and effort you put in.
Albert
EI7II
@@albert7ii Blessed, cursed, it's all the same.. lol. I would say my interest in electronics was certainly influenced by amateur radio. This included my interests in digital design. One look at that old ARRL handbook and we can see why. I had built an id system from one of the trade magazines using a bunch of 4148s hard wired to form the PROM. Maybe 73 or QST?
@@joesmith-je3tq Joe... irrespective. YOU have chosen to help us... "the great unwashed", out. The reason does not matter. What matters is that you CARE, inspite the occasional stupidity you endure in the NanoVNA forum.
The easy way would have been long ago to say: Well folks.... find someone who has a thicker hide and can do it better. Many take that route but you never did. I am absolutely convinced that the very great majority of us folks here truly appreciate your help and guidance, but as with so many things in life... few of us do stand up and say so.
So much the better if in the process of experimenting it gives you pleasure. Joe....As my brother.... (K6OPY) ( A silent Key) used to say: If you are Happy... tell my boss...if you are unhappy... tell me.
So... since you are your own boss... I am telling you.
Happy New Year Joe.... please stay safe and may you be our mentor and educator for many many more years to come.
Albert
@@albert7ii I would much rather people make use of the public forums and mail lists. At least it provides others an opportunity to learn. The videos are normally tied to what ever I happen to be playing around with at the time. My goal for making them has always been to help the next generation of EEs. This is why you will never see me asking viewers to subscribe, push a bell or join my patreon. It's also why I don't except donations for my software for these low cost VNAs. I suspect the late George Harrison would agree with you, the easiest thing to do is nothing. ruclips.net/video/Gc9Y_qkBysM/видео.html
Thank you Joe for all the great videos throughout the year. Happy New Year!
Thanks for taking the time to make these videos. The same to you, Happy New Year. Stay safe.
Thanks for the video Joe. Have a Happy New Years to you and your family.
The best to you in '22. Thanks for the great content.
Really enjoy how you present information. Very informative. Thanks for the education..
Merry Xmas and Happy Holidays, Joe!
Thank you for this, as a casual user of a NanoVNA it is useful to be aware of the potential limitation in some scenarios.
Thanks for your effort to share! It is interesting to listen about your experience.
Thanks Joe - excellent content!!!
Great video!
A very interesting video, thanks. Lots to think about here and how true regarding the way mistaken myths are born and proliferate.
Happy New year joe
Hope you had a Merry Christmas and have a Happy New Year. Been a rough 5 weeks here, got the wretched COVID with a double pneumonia thrown in for good measure. Feeling about 90% now after a few weeks on oxygen. Drummer in my band got it too and we both got hit the same day getting sick. Thankfully my wife never got it. Think she had it already in early 2020 so she had good immunity. Stay safe, I know about 30 friends and fellow musicians that got hit at the end of November. Today was the first day I felt like getting back to some electronics work at my bench.
Good to hear you're on the mend.
@@joesmith-je3tq Thanks Joe!!
The infected have to be transported to a Q-Zone.
@@1pcfred Move to Australia if that is your mindset.
@@SIXSTRING63 into the camp!
I watched this video and read your EEVblog comments and decided to buy a LiteVNA 64. Just got it today and am very impressed with the dynamic range, 1001 sample points, etc, (it's time to go tune some cans!) It allows me the ability to average out the noise from as many as 80 overlaid samples. While that's a slow process, I figure I can just enable that degree of averaging after I have the duplexers tuned close to peak. Good dynamic range, even with slow sampling speed, up into the GHz range would not seem easy to do in a dirt-cheap, pocket-sized VNA, but they did it. However, I will keep in mind the possibility of problems associated with the odd-order harmonic content. 'Know thy equipment'. Thanks.
A few people have asked me about using them to tune various filters and I typically refer them to the manufacture's manual for their filter. In many cases, I doubt the low cost ones I have looked at would be good enough but sounds like you claim otherwise. Of course, it's easy enough to compare the noise and dynamic range. The V2Plus4 is a little better. I did attempt to use them to look at a BP filter. This may give you some idea how they compare.
ruclips.net/video/XaYBpPCo1qk/видео.html
As I indicated, I have not yet done so, but I'm hoping to. While I'm a complete noob using VNA's I have used the technique of averaging out noise on my longwave communications projects with excellent results. My assumption is that the ability to average 80 samples will reduce the noise enough for me to do a good tuning. I obviously won't know for certain until I give it a try, especially as my math is poor so I need to do most things experimentally, but it seems reasonable. Am I missing something?
@@johnwest7993 I would have thought you would know what you needed to do the job beforehand was all and would have guessed the low cost VNAs I have looked at wouldn't be up for it. Even if you don't get the performance you need, they are still fun to play with and a great learning tool.
This is the right way to review VNAs, finally a video that puts real facts in order. I own minivna tiny (3GHz) from MRS, I was wondering if you could post a similar review, curious but also anxious about its true performance for a ~400 euro VNA, tnx, 73, SV1QZS
Sounds like you should write a book. Thank you for your careful production of this video.
I recently read a book that I felt contains a lot of tips for the beginner. I referenced it throughout making this video to give viewers something beyond my own experiences as a data point. ruclips.net/video/G4eLcTC4Ako/видео.html
Good luck redesigning the turbo encabulator. The trouble may lie with the fact that the main winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots of the stator.
I and others should utilize these objectives to transform our strategic thrusts in addition to expenditure involving risk general principals into short-run preferred areas of focus in addition to action general principals.
@@joesmith-je3tq that is not what our expert tells me ruclips.net/video/Ac7G7xOG2Ag/видео.html
Hi Joe, great video and an awesome channel. I wish I had known about your channel when I was working in the VNA industry.
You are rising an very interesting point about the signal quality of the generaters in a modern VNA. Even the top of the line VNAs started using DDS sources a few years back. I had a handful of customers who vehemently refused to let go of their HP8510.
As you demonstrated, even a VNA with a very bad generator can work flawlessly as long as the user is cognoscente of the limitations. I wonder how many of the cheap VNAs get send back because users think they are broken.
I look forward to your next VNA video.
I have not seen anyone actually show a problem when using the square wave drive. When I heard it mentioned, it seemed like a demonstration may prove helpful.
Which VNA do you recommend for checking and tuning SWR in 915 mhz and finding total gain from antenna thru coax to transmitter?
From my previous response to your same question: Assuming you just want to measure VSWR, maybe consider a good VSWR meter? At a GHz, you could make up a coupler and use your scope. If you are trying to measure radiation patterns, maybe a portable SA and your phone for GPS tracking? These low cost VNAs are a very good tool to learn some basic concepts. If you want to experiment above 300MHz, I like the V2Plus4 but they are seldom in stock. Another recent option is the Lite. If you want to experiment below 300MHz and would like to use it for narrow band work, I would stay with the original NanoVNA. I have not made a review of the Lite, but I did for the V2Plus4. ruclips.net/video/XaYBpPCo1qk/видео.html Of course, if you can't work with a squarewave drive, you will need to open your wallet. ruclips.net/video/y6iOTEU6Zzo/видео.html
I absolutely LOVE your videos!!!! I was wondering your thoughts on Flir multimeters? I own the DM166 and the DM285 and I was wondering if you have ever used or are ever going to test their meters? I have learned A LOT from your videos. I am just a auto tech with a meter collecting habit (PROBLEM). You put out AMAZING content! Keep up the great work!!!
I've never looked at any of their products. I haven't seen too much posted about them. It may be the cost. 6000 0.9% + 2 counts and low res IR, it may be a niche market.
@@joesmith-je3tq I appreciate you getting back to me. The DM166 kinda SUCKS! The DM285 I am pretty happy with so far. I guess probably because it's the highest definition IR I have used to date. I have a Fluke 189, 289 and a 80,000 count bench meter, so I wasn't too pushed about the low count meter. I just thought it was kinda neat having the meter and ir in one package for around the garage. I can definitely see where your coming from and probably could have put the money to better use elsewhere.
@@jamesaustin9848 So far I have kept my garage meters below $50. 2000 counts, 5% would be good enough for most of my needs. I want the backlight and TC input which rules out the free meters from HR. A few times I have needed a scope and ended up buying a couple of old Fluke scopemeters. I looked at a few different automotive meters that can directly measure some of the timing. You can see them here:
ruclips.net/video/q_89qoFMivg/видео.html
ruclips.net/video/uY6ZcINF7L0/видео.html
The TinySA (spectrum analyser) looks exactly like the LiteVNA and it has a sine wave output from 100KHz to 350MHz and a square wave output for 240MHz to 960 MHz. Either output can be configured as a signal generator , So it can be done in that price range and form factor.
The question was if we could have a VNA with sine wave drive over the entire operating range, not a small segment of it. Yes, we can certainly change those constraints and suggest is can be done.
@@joesmith-je3tq Yes, true enough. For the full range probably too expensive. I was just thinking it would help if they'd put in at least a sine -capable generator in for the low part of the range like what they done for the TinySA.
@@TheHWcave Personally, I would rather have the ability to measure narrow band devices and improved dynamic range at the lower frequencies. But we all have different requirements.
CP
"An interesting discussion. I think the main point is that if there's anything in the device under test that can go nonlinear (such as a diode or transistor), it may mess up the nano VNA measurement.
I wonder whether the nanoVNA actually puts out a continuous square wave signal, when set to zero sweep, or is there blanking involved?
"
I call all these low cost VNAs, NanoVNAs. They are the Kleenex of the VNAs. At 4:00, you can see the V2Plus4 does not have a continuous output. At 5:09 we can see that the LiteVNA is continuous. My original NanoVNA is also continuous. I suspect like the LiteVNA, there could be firmware that would force the V2Plus/4 to provide a continuous output when in CW.
Many people, including myself have posted how these low cost VNAs compare comparably with their commercial systems. I've tried to avoid the pitfalls of the square ware drive. It would be interesting to see what circuits people have had problems with.
You can see the waveforms here: www.eevblog.com/forum/rf-microwave/nanovna-custom-software/msg3908996/#msg3908996
Thanks for spreading the wisdom! Any thoughts on the libreVNA?
I stopped following the development after they started to censor my questions. From the little information I had gathered, you were locked into using their software. There was no documentation on how to control the device directly. Coupled with the high cost, I saw no reason to look at it.
@@joesmith-je3tq That's good to know, thanks for the heads up.
Other than the closed API, do you think something like the libre might be worth the money for doing full s-param analysis? It claims to calculate s11, 21, 12, and 22 simultaneously, which doesn't appear to be possible with any of the cheaper devices (s11 and 21 only); the ports can be swapped to find the other two, but that is useful only when characterizing reciprocal networks. I need something for non-reciprocal networks.
It's also unclear to me what the effect is in the cheaper devices of "ignoring" the signals that the full analyzers use to calculate s12 and 22.
@@HelloWorlds__JTS I guess if they stay in business, then it was worth the money for enough people. Again, having never looked at one, I am a poor choice to ask. As for what you actually need, I wouldn't have any way to know. I have demonstrated using transfer relay with these low cost VNAs. Of course these all use a squarewave drive which you may not be able to use. For home, I have a vintage Agilent 4 receiver PNA. Not a bad system for the age of it. ruclips.net/video/FuGWyXjSetI/видео.html
ruclips.net/video/y6iOTEU6Zzo/видео.html
Many thanks for this analysis, very interesting. I own miniVNAtiny by mRS, which is a ~$600 device, I was wondering whether you could carry out a similar benchmark comparison, should it happen to get it on hands, tnx, 73!
I doubt it. What made the original NanoVNA so popular was the $50 price tag. That and I showed you could actually pull decent data off it up to 300MHz. The LiteVNA gave the narrow band but you gained 6GHz, for a only $120. You would need to point out some reason why the product you mention out performs the these two. It appears to have a lower dynamic range, much lower BW, and triple the cost. Why did you buy it?
@@joesmith-je3tqIndeed, this is what I want to benchmark: MiniVNAtiny vs. Nano/LiteVNAs. I remember when I bought it back in 2016 ($350-400 then..) I was between this and RigExpert, but I chose the MiniVNA because I wanted 2-port measurements too, I can't recall anything else being around on the market then for a VNA around mid-low budget. I like that I have the option to select a high number of frequency points (e.g. 20 000), which gives a good glance when I sweep across all HF band in one go without worrying that I've missed anything (e.g. multiband antenna). But, you're right, the limited dynamic range (50dB) and the high price nowadays don't make it worth anymore. Note also that the original GUI developer has retired from mRS and God knows who will support/update the nva/J application anymore which is necessary to run the miniVNAtiny.... so, it seems that this device could become obsolete on the market anytime soon, unless something drastic happens. I am not a big fan of the GHz ranges on these budget-price devices, as they appear to be artificial in terms of performance and need very good broadband calibration kits (which most people omit/ignore), also I think that the average ham radio operator doesn't test anything above the VHF range, 1GHz is enough for the majority of the home-made projects. Nevertheless, on the current occasion I would go for the LiteVNA64. 73, SV1QZS
I've presented a lot of data for the LiteVNA64 above 1GHz. It's not like they are using harmonics like the NanoVNA and others above 300MHz. It has low enough noise that I was able to extend the frequency well above 10GHz with decent results. See my videos on rectangular waveguides. Most hams who write me seem only interested in measuring VSWR. Something they could do with a simple meter but I think they get told that the VNA is the thing. Many refer to it as an antenna analyzer. Back in 2016 when your Tiny was made, I was still using my HP8754A for home hobby use. Because it has no computer, I was forced to learn the math and the basics on how to run it. I used it up until a few years ago when I purchased an old Agilent PNA. For the low cost VNAs, I still use the standards supplied with one of them, but with a load that I sorted. All the data I present with them uses the ideal model, except for my experiments in the X-band.
Would the litevna 64 be good enough to tune antennas at 2.4 GHz and 5 ghz? Looking to purchase first analyser very new to this thanks 😊
There's a dedicated group for the LiteVNA (groups.io) that you should join. I don't do much with radios or antennas and suggest you ask people in that group.
Long story made short: The NanoVNA v2 is based on ADF4350 for the upper frequency range (that's the signal source). Checking the datasheet of ADF4350 its VCO runs between 2.2-4.4GHz so there it provides a sine. Below that it's a divided signal (so a square). It's so simple. As the rise(/fall) time of that (divided) signal is around 70ps that will resemble to a sine even when using a very capable scope in the GHz range, not to talk about less capable ones.
Side note: Because the divided output of ADF4350/1 has fast enough rise time it can be used to exercise the signal handling of sub GHz scopes.
Long story made even shorter: These low cost VNAs do not provide a sinewave output over their entire operating range. It's so simple.
@@joesmith-je3tq Classically, VNAs are meant for linear device measurements, and in fact S parameter theory assumes linearity. Agilent was hawking their proprietary "X Parameter" measurement methodology for a while, the idea being to extend Sxy measurements to accommodate nonlinear effects such as compression and (presumably) instability. Long story made almost as short: almost all VNAs other than the very latest/fanciest ones have untuned receivers. So if you expect source harmonics to be the only hazard when measuring unstable or otherwise-nonlinear active devices, you may find that even the venerated classic hardware from first-tier manufacturers lets you down.
@@NoahFect That's much longer.
@@NoahFect Yep, knowing the limits of a test equipment is usually more important than the equipment itself (one of the best lessons I've learned early in my education) and NanoVNA is just amazing for the price. Sure it has less dynamic range than the 2 or 3 orders of magnitude more expensive VNAs, it can't handle very narrow BW, output is not sine for a big part of its frequency range or it doesn't have tuned receiver either but that can't probably either expected from this price category. It's still usable for many tasks and for example startup time or portability can beat many of the more expensive benchtop equipments from not so long ago that cost a fortune and in many cases were hardly ever used for more than the NanoVNA can do (as a bonus the H4 variant can even save data for a more up-to-date storage than most boat anchors if one is willing to solder microSD card socket).
Btw. I've recently ordered LiteVNA too for around 1% of the price of a VNA that I can compare. A fair comparison, isn't it? ;-)
@joe smith
I'm just too lazy to start up an analyzer to check the level of the 3rd harmonic from the 2.2GHz up range but I'd be very much surprised if it was not a reasonable sine (significant harmonic level). Not to be a sine required a bandwidth for harmonics that is way beyond what is realistic in this setup.
@@edigi488Your story is growing. "... it can't handle very narrow BW..." Unlike the V2Plus4 and LiteVNA, the original NanoVNA does a decent job when measuring crystals and crystal filters. "...the H4 variant can even save data for a more up-to-date storage than most boat anchors if one is willing to solder microSD card socket..." Storage has not a problem as I run them headless.
nice range! bluetooth & wifi..super helpful!!🍌🍌🍓
Hey guys. Does anyone have tested LibreVNA project to check the wave output? It's quite more expensive than nanoVNA, but I didn't found information about the output wave format. If anyone have tested or know where to get this information, please share with us. Thank you!
Surely someone has made a video review of it by now showing the basics. If not you may want to just contact the designer. Another option may be to just look at the schematic or check their documentation for it.
Hi Joe
I wonder how these low cost VNA can be accurate even with linear filters. If a square wave drive signal is calibrated, the third and fifth harmonic entering the receiver add up to the measured signal. This is because the mixer has a conversion gain for the fundamental and the harmonics as the LO is also square wave. What happens if a filter only removed the fundamental or the harmonics? For example what happens with a notch filter (S21 is -80dB in the notch) that passes on all harmonics? I would expect the resulting measured signal would be the sum of the fundamental (-80dB) plus the third (-9.5dB) and the fifth (-14dB) multiplied with the mixer conversion gain for these harmonics. So how can you measure -80dB if the harmonics are not filtered out in the receiver?
The same for a brick wall filter. You expect 0dB in the pass band but since the harmonics are now gone you are probably going to see a fraction of a dB less even with perfect calibration.
Have you perhaps already looked at this?
Seems you're not considering the firmware. I've shown a few different filters and compared the results, for example: ruclips.net/video/XaYBpPCo1qk/видео.html
@@joesmith-je3tq Thanks for the link Joe. I guess you are right. Since this is not zero IF, the harmonics can be filtered out easily.
@@blaap Still, I agree with what you are getting at to a point. You can easily imagine testing a high gain amplifier that would overload the VNA when excited with the harmonics. I suspect we don't see too many people posting of problems as many are considering the VNA an antenna analyzer. A few may look at passive components but very few are looking at active circuits. Just a guess. I figure for the sub $200, it's still a great tool for learning. At these prices, the beginner can make a fatal mistake (hooking it directly to their power amplifier for example) and replace it.
@@joesmith-je3tq Even at work I could use this. Much more portable and no worry if it's gets damaged (ESD?). Problem is more that the instrument then needs traceable calibration etc.
@@blaap Odd. While I have seen people post about using them for professional use, I wouldn't have considered traceability a concern.
I cant think of a way to put a sine wave drive in to a product that small, over a range that large and at a cost below the entire cost of the VNA
It's not so difficult. A square to sine wave converter can be made with a nonlinear circuit (some diodes and resistors).
@@blaap over the entire frequency range keeping the amplitude constant?
I cant think of how that would be accomplished
even in narrow bands you will see an arc like voltage curve
@@OneBiOzZ I was wrong. What I was thinking about would only work with a triangular shaped wave, but that's not what we have here.
You use a vna v2 plus 4? Who manufactured it? Was it HCXQS? They were the co. that created this model. Others are clones. On their site they show some of the clones and how they work and the parts they use.
Yes, I have a V2Plus4 and have a review for it. I bought both the V2+ & V2+4 when they first became available from OWO's store. You can find the review here if interested: ruclips.net/video/XaYBpPCo1qk/видео.html
For what it's worth, the Tinysa does put out a sine wave on it's low port which goes up to 350 mhz. The high port which goes to 900 mhz puts out a square wave. I have been trying to use both vna and the sa together. The tinysa works very well as a test oscillator to test receivers. What is neat about the tinysa is that both ports can be used as inputs or outputs of signals.
I've heard that the common ground with the computer through the USB connection can cause problems. Could you try it without the USB?
Try what exactly?
@@joesmith-je3tq To do the same measurements without having a USB connected on the nanovna.
@@CostasLilitsas I was showing the difference of the software and firmware average. It will be difficult for the software to communicate with the LiteVNA when it is not plugged in. When I measured the output voltage with the scope, the Lite was not connected to the PC. Also consider that the only time I had anything connected to the Lite was when I attached the thru. We are just looking at noise. As I said in the video, it wasn't important as I was only showing the update rates.
If you had read something on the internet, maybe just provide a link to it.
@@joesmith-je3tq First of all, thanks for taking the time to answer me, it's not for granted. So here's what I'm talking about. I saw this video that shows a tinysa being affected by the common ground between the PC and the tinysa through the USB connection: ruclips.net/video/E2bxZZXyVoE/видео.html So I was wandering whether the same thing could affect the nanovna's measurements. Of course you need a USB connection in order to use the software, but you can always use the device's screen instead. I was just curious of whether it would show anything different. Thank you for your time.
Start reading here: www.eevblog.com/forum/rf-microwave/nanovna-custom-software/msg3887012/#msg3887012
Hi Joe, would you like to resel to me your pencil ? Wish you all the best....
Found some on eBay new in the pack! Treat yourself. www.ebay.com/itm/324179138527?hash=item4b7a9517df:g:lBoAAOSwhrFeza8F
I'm genuinely curious who the 10 dummies were that thumbs-downed this video.
Nice! I just found "Vector Network Analyzer Measurements and Uncertainty Assessment." I'm looking at reviews now. Best Wishes, Kenn
If you buy the book, let me know what you think of it. So far, I would say most of my nuggets have come from reading the few patents available. The leave out a lot of details and my skills are far too lacking to make use of them.
I've started reading Spectrum And Network Measurements. Started at beginning because I'm ignorant. I chose this book because author works through the basics. The bibliography for chapter on vector network measurements includes several Agilent publications between 2002 and 2012. This looks to be a very detailed paper:
Applying Error Correction to Network Analyzer Measurements
@@joesmith-je3tq Its AWESOME!
@@kennarnett8220 Thanks. I'll check it out.