User feedback on KC901S+ and KC901V handheld network analysers

[RFDUK]

The KC901 products potentially look a very attractive addition to an RF lab, particularly for field work, off air level monitoring of systems in dev, antenna tuning and debugging plus usable VNA performance with good presentation of the numbers.

The Signal Path review from Shahriar gave me a positive view of the value in these instruments.

Are there any owner / users of any KC901 instrument that would offer their experiences?

Many thanks.

[Safar]

do you want to listen to what you dont want to listen? i'm a KC901V owner and i think the sole owner in this forum.

Me also.

[Safar]

Of course this device can do some measurements, but need to understand that is not "fieldfox" and have a limitations. For this price it works, but I can't compare it with more serious devices as I don't have them.

Some of Limitations (901v):
1) Lower band (10..50kgz) looks not good. But I think external coupler will help as device can works in this mode. Don't use it yet.
2) SOL cal don't use fringe effects in calculation. You can enter only electrical paths length of each of SOL parts. But I think that is enough for device measurements accuracy. Also you can save any measurements in files on microSD card and feed it to some external applications, even make calibration with all coefficients.
3) Gen have a lot of spurious (suppose it have fractional divider pll)
4) Spectrum analyzer have max 30KHz RBW, so if you want to look at wide band or use small number of samples you have big chance don't get all spectrum info. I think that warning sign will help to pay attention to leaky spectrum but device have no any sign now. May be I will write to support.
5) You should look first to support site and make your opinions. For me is a little bit strange this kind of service. But good news that new FWs released regularly

I saw some application in github but don't try to use it. It may be helpful for transfer data to PC directly as device have LAN port.

In general device leave good impression for me.

[RFDUK]

Many thanks for the information Safar. The PC data linking is interesting, I'll take a look.

A full PC control with screen for bench use would add significant value for me, but no sign of that.

It's very useful to hear from an owner with a good impression.

[Mechatrommer]

I saw some application in github but don't try to use it. It may be helpful for transfer data to PC directly as device have LAN port.

can you provide the link? i thought i saw the open source code for the VNA somewhere. but i cant find it anymore.

5) You should look first to support site and make your opinions. For me is a little bit strange this kind of service. But good news that new FWs released regularly

the bbs site has become spam heaven. you need to scroll few click down to get the link.

It's very useful to hear from an owner with a good impression.

Shariar's review alone will be adequate for you then

[Safar]

https://github.com/bg8npk/KC901S

But I see that is just c++ source code (but with corrections for 901v). Need to compile.

[TheSteve]

Dr Kirkby wasn't impressed by them I guess:
http://www.kirkbymicrowave.co.uk/support/VNAs/Deepace/

[Safar]

Dr Kirkby wasn't impressed by them I guess:
http://www.kirkbymicrowave.co.uk/support/VNAs/Deepace/

Hi! Suppose the reason is that Deepace make SOL cal in current FW without fringe calc. So think Deepace users not a target group for Dr. Kirkby But as I understand it possible use some PC application and make all calibration on PC side with all fringe data.

Of course nobody tell here that Deepace make magical device for 2k$. Think it don't have enough accuracy for use fringe data.

But for me personally very interesting how good his standards on 6..7 GHz (as he used "retail" parts as I understand). Especially in _stability_ side. I read Kirkby topic here and saw some doubt on it. But it is only one trust suggestion in middle level price who make all data for selled standards.

For use with Deepace I bought SMA Rosenberger kit on SDR-kits as it have delay data.

[TheSteve]

Yeah, obviously the price always has to be factored in.

[RFDUK]

The review by Shahriar observed LO PLL instability at higher frequencies. Does anyone know if that was resolved by Deepace?

I'm waiting on a second response from the factory but they don't have a difinitive answer yet.

[dk5ya]

The review by Shahriar observed LO PLL instability at higher frequencies. Does anyone know if that was resolved by Deepace?

I have never been able to determine that yet. Also on the analyzer (Siglent 3032X) I could not detect any problems with the LO. But I measure regularly only up to about 2 GHz.
Its a KC901S+, bought back in October last year.

Udo

[Wirehead]

The review by Shahriar observed LO PLL instability at higher frequencies. Does anyone know if that was resolved by Deepace?

I have never been able to determine that yet. Also on the analyzer (Siglent 3032X) I could not detect any problems with the LO. But I measure regularly only up to about 2 GHz.
Its a KC901S+, bought back in October last year.

Udo

Where did you buy it in Europe - trying to avoid any extra customs fees.. What's your opinion / experience on the device up to now? I'm also looking at the 901S+. Have you used it in the HF part as well?

[dk5ya]

@Wirehead: you have mail.

[Wirehead]

@Wirehead: you have mail.

Thanks Udo - appreciate it! 

[Ivan7enych]

Hello,

I've got the KC901V several month ago (mainly because of Signal Path review).

For me it works best in S11 measurements, I can test both 2.4GHz antennas and 5GHz (for FPV copters).

S21 accuracy is limited by 2 things -
1. poor 50ohm matching of output and input ports, this can be improved a bit by 3-6 dB attenuators at output port.
2. internal leakage between ports on frequencies (> 3-4GHz)

[Electrical Science]

I've made a little repair video about KC901v.

[Mechatrommer]

I've made a little repair video about KC901v.

i dont watch all of the video, its too long, i only skipped to important part. but congratulation on your fix. i think this is exactly what happened to my KC901V a while a go. i sent my unit back to China for repair at a cost of DHL courier shipping and they sent me back the unit fixed at their cost. i snapped photos of pcb before repair and when something happen again i will open it up and i should be able to see which part they were replacing.. i suspected on some gain amplifier but i dont want to risk buying the wrong part (LMC788A is a $10 IC not cheap) and wasting time, it was still under warranty with only few weeks left.

otoh, if you havent updated the KC901V firmware, i suggest you do so by downloading from their website (make sure it is for KC901V not KC901S, you can screw your VNA if wrong FW) since new FW will include both fringing capacitance and fringing inductance parameters into CALibration process, something that was not available even in Holy HP/Agilent or FieldFox VNA, it may not matter much but well, its always better to have than not (i usually left them 0s anyway, until i make further study on this later). we the bbs forum members were raising and pushing the issue and luckily they listened, i give them thumbs up for this but unfortunately the bbs forum was closed down, this is a thumbs down. but in the end, i'm still happy with my KC901V even though many challenges i've gone through with this.

edit: and i forgot to tell, there is one level deeper menu to recalibrate internal frequency sweep on those port by pressing some combination keys while in normal menu interface (read the manual its there i cant remember now). before this internal calibration (before fix) i can set 0dBm on GUI, but actually very low output, when i recalibrate, then i only can set like -20dBm max iirc on GUI, so i guess the sweep calibration process is using actual output level detection. and then actual output match that is set in GUI. after factory fixing, i guess they do the internal recalibration and my frequency sweep can be set to 0 to 10dBm again, cheers.

[W4HBM]

Gentlemen,
Regarding the DEEPACE KC901s+ Vector Network Analyzer.....
The situation here is the VNA is to be used under 200 MHz, Never taken to the field, cradled in a wooden fixture on the bench, not connected to
a computer via USB or Ethernet, not used in the Remote Status.

The current FW update level is v1.2.3......

IMPORTANT: Never Drop The Meter More Than A few Inches (<3). If you do, send it back to the factory.

(v1.2.8  &  v1.2.9  do not seem worth all the effort and time just yet, but INQUIRY HEREIN as to whether v1.2.8 is important ( !! )

The RF Trainer module is mounted on a wooden frame, held with small globs of Butyl Rubber to afford electrical & physical isolation.

R E P O R T:

1) If handled very carefully and allowed to warm up judiciously, the '901s+ remains stable.
2) The Battery Charge active Icon is somewhat misleading. e.g., What are the "planets" circling the colored "sun?"
3) Do the "planets" indicate how many battery units are installed within?
4) Disassembling the analyzer chassis is not for the faint-of-heart. I cannot imagine what sort of hammer to use.....
5) The detailed Info screen is somewhat difficult to navigate, and then when landing on the parameter, what then?
6) Oftentimes, using a high-quality test lead and SOL set, it seems the Factory Cal is better than the DUT rig.
7) Gathering a high-quality test lead set altogether an important requirement. Any fudging yields Chaos.