Deepace KC901V 6.8GHz Handheld Network Analyzer Review, Teardown & Experiments - Page 1
Forum section: electronics / testgear

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 14, 2017, 08:22:19 pm
content: In this episode Shahriar reviews the Deepace KC901V 6.8GHz handheld network analyzer. This battery-powered instrument is an RF multi-instrument integrating VNA, spectrum analyzer, field strength meter, and a low-frequency signal generator. It can also perform signal port vector measurement and 2-ports simple vector network analyzing (S11, S21). The review is organized as follows:01:24 – Instrument overview & block diagram.05:36 – Full teardown along with RF and digital board analysis.14:30 – Power on, calibration and S11 measurement of an antenna.23:46 – Calibration for S21 and measurement of a tunable filter plus phase shifter.32:23 – Distance to fault measurement of an SMA cable chain.36:24 – Spectrum analyzer measurements and limitations.43:16 – Signal generator measurements and issues.48:20 – Other features and concluding remarks.50:07 – Giveaway!You can watch it here: [51 Minutes]youtu.be/LN9PKKdFiboMore videos at The Signal Path:www.TheSignalPath.com

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 15, 2017, 12:07:42 am
content: CORRECTION: At 10:07 those components appear to be filters and not oscillators.

author: technogeeky
author_rank: Frequent Contributor
timestamp: May 15, 2017, 02:04:59 am
content: Pretty cool little device. And it's pretty cool they let you keep the parts unit they shipped to you, to give away. And it's pretty cool that you're giving it away!Now I think I understand that my aforementioned Agilent E7495A must be doing S21 and S11 measurements on the RF out/in port. So the E7495A has at least a spectrum analyzer, CW, complex modulation on top of the CW, a VNA capable of doing one port S21 and S11 measurements, and also capable of doing two port S21 measurements also. And it of course also has DTF. I suppose the main disadvantage is that the lower limit on the CW output and therefore all of these measurements is 350 MHz, which is quite a limitation.Anyway, the prospect of 1 in ~ 300 chance of getting the VNA enticed me to finally spend some money and become a patreon supporter. Have you decided when the cutoff/drawing will be held?Thanks,-tg

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 15, 2017, 04:35:46 pm
content: Quote from: technogeeky on May 15, 2017, 02:04:59 amI'll do a random draw later today.Cheers,

author: owiecc
author_rank: Frequent Contributor
timestamp: May 15, 2017, 08:51:29 pm
content: Can you link to the paper you mentioned at17:30?

author: hendorog
author_rank: Super Contributor
timestamp: May 15, 2017, 09:17:07 pm
content: Great work, just did the patreon thing as well.

author: nowlan
author_rank: Frequent Contributor
timestamp: May 16, 2017, 02:27:23 am
content: I was asking a local teacher/ham about spectrum analysers last month, and he recommended one of these instead.I didnt see much about it on eevblog. A couple of really old posts that didnt go far.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 16, 2017, 02:35:24 am
content: Quote from: nowlan on May 16, 2017, 02:27:23 amPlease keep in mind that this would not make a great spectrum analyzer as I have shown it's limitations during the review. The spectrum analysis is a secondary function of this unit.

author: technogeeky
author_rank: Frequent Contributor
timestamp: May 16, 2017, 02:49:31 am
content: Quote from: Hugoneus on May 16, 2017, 02:35:24 amEspeciallyfor a beginner. Hooking up an excellent CW source like that and seeing absolutely nothing on the screen would be nearly baffling to a beginner. And that's the best case, where you know exactly where the signal would be. Imagine trying to find an unknown signal that way...

author: rx8pilot
author_rank: Super Contributor
timestamp: May 16, 2017, 03:10:43 am
content: At $2k, its a pretty cool device. Leaves room to get a proper spectrum analyzer and you would necessarily need one with a tracking generator.Sent from my horrible mobile....

author: TheSteve
author_rank: Unknown
timestamp: May 16, 2017, 03:17:29 am
content: Quote from: Hugoneus on May 16, 2017, 02:35:24 amCould they not include a mode that alternates between upper and lower LO's and then uses software to remove obvious high level images?The small RBW is a bigger problem unless they want to add a massive amount of sample points which will probably really slow it down.

author: technogeeky
author_rank: Frequent Contributor
timestamp: May 16, 2017, 03:22:08 am
content: Quote from: TheSteve on May 16, 2017, 03:17:29 amPlus, the resolution of the screen is an actual limitation here, isn't it?

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 16, 2017, 03:22:25 am
content: Quote from: TheSteve on May 16, 2017, 03:17:29 amIndeed this is possible and is regularly done with external mixers on various spectrum analyzers.But as you said the second IF filter really limits this instrument on wide spans.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 17, 2017, 01:39:53 pm
content: It is definitely good that it has the SA function. Just can be a trap for beginners.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 22, 2017, 06:27:02 pm
content: i bought this item few weeks ago, i tried to get sma calibration kit from MrKirkby specific to this product, he adviced to avoid this product because some flaws, such as we cant input calibration kit coefficients (stray capacitance or polynomial whatever it is) into the unit. i reported in their bbs forum, no reply from the engineers i guess they are sleeping, i emailed them they dont answer (they only answer when you want to buy this thing), now i cant access their website while others have no problemhttps://www.eevblog.com/forum/chat/need-human-verification-if-www-deepace-net-is-accesible/msg1329016/#msg1329016.bad service, not a recommended producti guess they successfully lured TheSignalPath to give a good review on this stuff and he havent look this thing into more details.

author: chris_leyson
author_rank: Super Contributor
timestamp: October 22, 2017, 07:31:51 pm
content: Thanks Shahriar nice review, a great little instrument for dual band antenna design, like it.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 22, 2017, 09:26:57 pm
content: Quote from: Mechatrommer on October 22, 2017, 06:27:02 pmWhere do I start...1) You can see the calibration screen and the parameters which can be entered clearly in my video:youtu.be/LN9PKKdFibo?t=16m23s2) The manual of the unit clearly states what can be entered:S11 abides by SOL calibration, in which the three capital letters respectivelyrepresent 3 types of calibrators: short, open and load.KC951011/KC951012 is the SOL calibrator that we (Kexinshe) produced. Users canalso use other proper calibrators, but keep in mind that the terminal effect of thechosen calibrators must be small enough since there is no compensation for KC901V(non-commercial version). KC951011’s nominal electric length is 5.26mm andKC951012’s one is 0. If a user chooses other standard, he/she needs to input thevalue of the actual electric length in the FUNC interface.I didn't give the unit a "good" review or "bad" review. I showed exactly what it can do and what its limitations are considering its price.This is the second time (that I am aware of) in the past few weeks which you have smeared my work due to your own ignorance and self-entitlement.

author: rx8pilot
author_rank: Super Contributor
timestamp: October 22, 2017, 09:49:47 pm
content: I think when he saw 'SOL' it was interpreted as 'Shit Out of Luck'

author: technogeeky
author_rank: Frequent Contributor
timestamp: October 23, 2017, 03:16:31 am
content: Hugoneus:In this video you mention that there is an interesting paper where the development of the various n-term (6-term, 12-term, etc) models for calibration of VNAs were developed -- that its a good paper and worth reading.Can you give us a reference or a title so I can try to find it?

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2017, 06:00:33 am
content: Quote from: Hugoneus on October 22, 2017, 09:26:57 pmi know that (i bought this unit remember?), but its just the mechanical offset length that is user adjustable. fringing effect offset to open standard, which is frequency dependent cannot be set.Quote from: Hugoneus on October 22, 2017, 09:26:57 pmmeaning that... KC901V cannot be used with any calibration kit, even the most expensive one, if its not following the"terminal effect of the chosen calibrators must be small enough"criteria, let alone diy cal kit version. and how small is "small"? is anyone's and the KC901V's FW guesses.Quote from: Hugoneus on October 22, 2017, 09:26:57 pmand many more comments as such before that... the only negative side you mentioned iirc is the limitation of SA functionality... but i tell you what, i still agree (and respect) in every aspects of what you said in the video, except you missed the most important limitation of the VNA (its main advertised purpose), ie it cannot user adjustable terminal (fringing capacitance) effect. this make the measurement output of the device is questionable. other expert highlighted that many advises in the manual are nonsensical, and you just highlighted one of it... how small is small the terminal effect? this is non-technical person writing the manual.Quote from: Hugoneus on October 22, 2017, 09:26:57 pmexcept this, you seems to take things more seriously into personal affair. i try to shoot the other people but you seems to take the hit, too bad... the earlier one is one ignorance blaming tektronix due to their ads popping out infront of your video. blaming tektronix is blaming the wrong guy out of ignorance, i just tried to advice him, if "he has to blame" somebody, the video publisher should be more appropriate person to shoot at, but i dont mean you TheSignalPath is rightfully to be blamed, its just he liked to blame anybody. i cannot make counter reply to the post since the thread is locked (due to gender attack etc).and now the 2nd time is this, i try to shoot deepace, but you take the hit, why? deepace paid you? i got pissed off by their incompetent at support service. even if how good their products are, if they dont bother to reply to their unsatisfied customers, would you still recommend them? who has to be blamed? the person who lure? or the person who got lured (victim)? i dont blame the victim ok. but instead of educating, warn people and look more into this matter seriously, you keep continue mourning how innocent you are and how perfect your reviews are that anybody cannot say negative about it, you only like to hear positive reply, then i guess you have some motive behind all of this, and my respect to you will go down logarithmitically. i'm sorry for the misunderstanding...Regards...

author: technogeeky
author_rank: Frequent Contributor
timestamp: October 23, 2017, 06:29:02 am
content: There's a lot to attack in your post, but I'll just pick one specific thing and start there.Quote from: Hugoneus on October 22, 2017, 09:26:57 pmBullshit."I guess they successfully lured TheSignalPath" isclearlyan attack on Shahriar's character, his credibility, and his openly stated values.QuoteTwo things:he made no attempt to review Deepace as a companyhe can't (to the best of my knowledge) see the futurehe doesn't have a fucking time machineCriticizinghis omissionof a statement about poor product support from Deepace becauseyouhad a bad experience several monthsafterhe published his video requires the reasoning of a madman.QuoteYou didn't say something negative about his video, you said something negative abouthim. That's very different. I am not aware ofanyother electronics blogger who is as self-conscious about the quality and particularities of his videos, and it's completely unnecessary. It's assholes like you who go around incorrectly contributing to this self-doubt with attacks on his person which are partly to blame.Furthermore, the idea that he's in the pocket of "big Deepace" istotally absurd, andthat'sa further insult to his intelligence. If you think a man who has access to multi-million dollar test equipment at work, and has a home lab with perhaps a quarter million dollars worth of quality test equipment from world-class vendors... if you thinkthatsame man is going to be corrupted by the mere offering of free thousand dollar piece of quasi-professional test equipment from some upstart company...It's a wonder that you haven't made all of us insane on EEVblog forums with your level of critical thinking applied over those 8000 posts of yours.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2017, 08:05:23 am
content: Quote from: technogeeky on October 23, 2017, 06:29:02 amso any viewer who satisfy with the review will... buy anAgilentVNA?Quote from: technogeeky on October 23, 2017, 06:29:02 amwhere in my statement expecting him to be?Quote from: technogeeky on October 23, 2017, 06:29:02 ami dont reply to this childish statement.Quote from: technogeeky on October 23, 2017, 06:29:02 amrelated to his video, i dont expect him to know or give any comment on the company's support, but specifically on the VNA's limitation of terminal effect coefficient, he can correct that in this thread or in comment in youtube, just like he corrected his comment on filters vs oscillators mistake. continue claiming the perfection of his review is an act of self entitlement...Quote from: technogeeky on October 23, 2017, 06:29:02 amwhere?Quote from: technogeeky on October 23, 2017, 06:29:02 ami wonder if you pass language subject in school or not, can you differ a statement with a question mark? yes the question is a provocation, but the answer to that will show the quality of the person...his choice...Quote from: technogeeky on October 23, 2017, 06:29:02 amkeep up the good attitude, you think i'm buying it? nobody is God, i wont back somebody for the wrong cause just because he gave some good reviews and impression of expertise.what i'm trying to say is he missed something a fact in his video, which a newbie like me figured out later. he may choose any intelligent way to defend (or admit it) the way he like. now he defended with a statement from Deepace's manual. if he expects anybody to understand what a "terminal effect" is by omitting it in the review, then fair enough... here again in this review thread, i say to all newbies out there like me, if you are thinking to buy KC901V just because you think its worth the price, then you should go and learn what is fringing capacitance effect means. if by neglecting the effect, the result is ok for you, then go buy this cheap thing, undoubtedly its the cheapest on the market for whats its claim for, but if the effect is of the concern, then be warned. i like to quote the other expert's saying in our conversation...Quote

author: technogeeky
author_rank: Frequent Contributor
timestamp: October 23, 2017, 08:23:41 am
content: Quote from: Mechatrommer on October 23, 2017, 08:05:23 amAnd what world-class microwave laboratory are you in charge of at your day job?This is your third or fourth personal attack on Shahriar. And you just gloss over all of them.There's no need for any of us to talk to you any longer.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2017, 08:38:45 am
content: Quote from: technogeeky on October 23, 2017, 08:23:41 amtoo much assumption on you i dont know where you are getting the imaginations. i dont blame you for thinking anybody you like as everything, its typical for a newcomers, i also once almost got sucked by this hypnosisQuote from: technogeeky on October 23, 2017, 08:23:41 amgood lord, lets this thread as clean and as informative as it can be, not by anybody who are too emotionalnow lets get back to technicalities...

author: all_repair
author_rank: Frequent Contributor
timestamp: October 23, 2017, 08:57:05 am
content: You paid the school fee for us. I was monitoring them on their Chinese forum. But very uncomfortable with the way they coming out their products and their developments at the expense of their supporters. They also raised their price rapdily. A group of young techie trying to get rich very fast in a rapidly growing country. My impression of them is they think they are very good, and so trying to get the rewards they think they should get. This K... thing is a path they are trying out, and shall discard at the first instant.

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2017, 09:04:33 am
content: Quote from: Hugoneus on October 22, 2017, 09:26:57 pmWelcome to the club

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2017, 09:07:51 am
content: Quote from: technogeeky on October 23, 2017, 06:29:02 amJust so. Quantity != quality.Occasionally he makes reasonable and reasoned points, which makes it more difficult to ignore him out-of-hand.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2017, 09:52:20 am
content: Quote from: all_repair on October 23, 2017, 08:57:05 amwhy not just name and shame? btw... the way i see it, this is purely mathematical, hardware only provide the values to some parameters. fringing effect can be embedded in the math formulation in the FW, its just a matter of adding it in user adjustable setting, no HW changes needed. but, correct me if i'm wrong. i would expect a reply just "we are sorry we will work on it" or some simple techical explanation on how to deal with it, but none, zilch, zero reply. it was ok when i tried to make the purchase.

author: technogeeky
author_rank: Frequent Contributor
timestamp: October 23, 2017, 10:28:56 am
content: Quote from: wilfred on October 23, 2017, 09:32:19 amThis was of course apparent to me when I wrote it, but I agree with all your points (except the one about lured -- but it's not important), and I apologize for the personal attack.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2017, 11:37:29 am
content: Quote from: wilfred on October 23, 2017, 09:32:19 ami'm sorry if the word is wrong, but i saw the word used when a villain tried to persuade his victim to do what he want.. it can be a fisherman to a fish, or a big guy giving candies to a children on front page of a news. victim is not to be blamed, but what is sad is when the victim says, no daddy daddy this is a good guy! in this case, i'm the 2nd level victim (the daddy) where TheSignalPath is the 1st level victim (the child). thats the way i see it up until this minute (until they the deepace try to sort this issue out)...btw, i dont think KC901V will be entirely useless just because of the technical reason, it might be off, but i hope by just a little (hope? what a concept, i tried to be as tolerant as i can to this device allright), i will still use this device as "guesstimate" of a measurement, still better than nothing. like the rest of china products scattered around in my room, this $2K device, i'll need tweaks or workaround to make it works to the accuracy that i desire, i got used to this (i need to become a VNA designer after this by studying all the subtleties needed in order to know how much far off i am with the measurement result). this is a "you get what you pay for" device, if the company replied to my issue, i would give the product neutral rating, but since they dont answer, then itsjust to counter balance the good review from Shariar... fwiw...

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 23, 2017, 01:58:10 pm
content: If you are unhappy with technical support from the manufacturer, you are free to post it here. I did not review their customer support, nor I could have.This can be done without lies and attacks on me. I thought such a simple idea would be self-evident. Don’t take out your frustration by smearing my work. Behave like an adult.There is nothing else that is needs to be said.Thanks to those of you who understand this simple fact.

author: technogeeky
author_rank: Frequent Contributor
timestamp: October 23, 2017, 02:30:45 pm
content: Quote from: Hugoneus on October 23, 2017, 01:58:10 pmJust to not let it get lost in the noise, please let us know if you can remember the paper detailing the history of the calibration methods mentioned in this video!

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 19, 2019, 06:08:40 pm
content: an update... i just browsed Deepace website and now FW 1.3.4 update for the KC901V. whats interesting is that they have implemented fringing coefficients for both Short (L0, L1, L2,L3) and Open (C0, C1, C2, C3), this is beyond expectation, as Kirkby CAL Kit only provides coefficients for Open Standard which is applicable to Agilent, R&S, Anritsu and Copper Mountain VNA. with this update, it surpasses those brand names (in that respect only) and invalidates all my previous comments on the lack of KC901V parameters (should i delete? or should i keep for historical reason?) i believe this upgrade is due to push from few KC901V owners in the Deepace BBS forum (i tried to login to give applause feedback but its in maintenance mode now) and the VNA manufacturer did listen and fullfilled their promise few months ago. 4 thumbs up to themi think i will need to contact Dr. Kirkby to ask how to obtain fringing "inductance" for my CAL kit... btw, i also just noticed Deepace already published their KC901M 9.8GHz VNA @ sub $3Khttp://www.deepace.net/shop/kc901m-9-8ghz-handheld-network-analyzer-rf-multimeter/still some typo and copy paste there, but try to get the same BW from big brand names, you can lose arms and legs.

author: TheSteve
author_rank: Unknown
timestamp: March 19, 2019, 06:36:47 pm
content: It's great they added them. Had anyone done any testing to see if a difference can be perceived?I believe it's been stated many times that below maybe 6 GHz the difference is in the noise. Still, I hope you can publish some results if David can provide the inductance values.