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Hello everyone
I would like to present my new project, a Vector Network Analyzer for measure filter, antennas .......
for more info & photo
web site
http://www.metrovna.it/
info
aferrulli@gmail.com
Thanks
IZ7LDG
Antonio
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This looks very good! Is it possible to buy one from you? I feel like that info is missing from your website, how to get one
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Pretty slick, an amazing amount of work I'm sure.
I love that you still consider a 16 MHz micro powerful ... that's old school (But I agree, with efficient programming it's more than enough.)
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Hello
and 'can buy this tool kit or already' installed. It 'available in a short time. I am attaching some photos of the interior menu ......
I created a group, on Yahoo METROVNA
Web
http://www.metrovna.com/
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Hello
these are the features and specifications below are photos of some of the measures of an antenna and a filter
Technical Features MetroVna Pro Touch 180 mhz
Coverage 1/180 MHz 160/2mt
Measure R,Z,|X|,SWR,TL,|Phase|,ReturnLoss
Exit DUT -6dBm su 50ohm
Max signal imput –70/+5dB
Accuracy +-2dB
Operating voltage 3.3V
Dimensions 125mm x 95mm x 20mm
Weight 200gr
Functional characteristics
Display TFT 3.1” 16 K coloritouch screen
Ten Menu + four service menu
Internal Rechargeable Battery LI-ion 5000mAh
Battery charging circuit
Interface USB / Bluetooth
updating Firmware USB
compatible with IG/VNA, VNA/J , BluVNA and more
Compatible with Tablet,Smarthphone Android
Platforms SW WIN,LINUX,ANDROID,MAC
IZ7LDG
Antonio
aferrulli@gmail.com
www.metrovna.com
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What sort of price are you going to sell them for? Looks much better than the common MFJ and Diamond units out there now.
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I do not know exactly depends on the quantity ' think around 200Euro
do you like? I'm collecting suggestions ??
I post some pictures of the inside of the PCB assembly
Thanks
Antonio
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Quote
do you like? I'm collecting suggestions ??
Yes, providing it's designed right, with decent software and documentation for that price it will be a killer. -
Hi Antonio,
I think that in the range of 150 - 200€ would be a killer, if the design is right, if it's accurate on the measurements (precision), I know the more precise, more expensive, but it could be a trade.
Make sure that the 16MHz processor still have enough room to improve and to add new functions with software updates in the future.
SMA or N connectors of good quality.
For a second version I would be happy to see one from 140MHz-1.3GHz or 3GHz. -
I am very happy that you like
The mission and 'make a kit very cheap and easy to assemble. The whole circuit and 'designed to reduce costs. The Metrovna and 'very fast and accurate in sizes and specifications that I have listed are provisional. The VNA has a powerful 32bit processor 32MXFX575 of the microchip. The instrument has 10 internal expandable menu with everything manageable touchscreen.
The firmware and 'very complex and' consists of about 10,000 lines of code. And 'can calibrate whith software and runs on all platforms WIN,LINUX,MAC,ANDROID, on PC,TABLET,PHONE ......
73'
Antonio
IZ7LDG
http://www.metrovna.it/ -
Very impressive package and it looks functional as well. Can you share the basics of the circuit? Did you use I/Q sampling for the phase? Analog Devices chips?
I've been designing VNA units using some of the newer Analog Devices chips. They have a host of I/Q modulators and demodulators as well as log and linear detectors. It is getting to the point where you can build a VNA with power measurement (without an attenuator) using about three chips plus the CPU. Also, the new Minicircuits micro transformers can be used to build return loss bridges or directional couplers that are relatively flat from 1 to 800Mhz and would fit on a US quarter.
The chip that has a lot of promise is the Analog Devices ADL5519. It is a dual log detector (no phase) that is good from 1Mhz to 10Ghz and handles 62db range I believe without external scaling. This means you can run a KW with the right directional coupler or RLB and measure both forward and reflected power simply. All you need then is an I/Q demodulator and a DDS and you have a complete system for tuning an antenna and measuring power. Every time I go to their site they have a new RF product.
Another company that is making headway in this area is Linear Technology. The have a number of detectors, log amps, I/Q mods and demods, etc. They have always had low noise amps so I've been looking for their competing devices to AD.
Anyway, please share your block design. Nice design and packaging.
thanks ,
jerry -
Hi cncjerry, how an IQ demodulator would work if the output of the ADL5519 is DC ?
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The adl5519 is used for the power measurement function of the device, not in the VNA per se. It is oriented towards RSSI I believe. You would be able to use it to tune an antenna though, come to think of it, as all you would need to do is sweep the band using a DDS and measure the 5519 output with an ADCB. This would give you SWR and impedance but not phase. The problem is this device is still too expensive. The DDS cost $10, the microprocessor a few more and the RLB transformers are like $5 a pop and you need four. With circuit board etc, it would be hard to get the guts of it below $75 in low quantities. But you would have a 0 to 1.2KW highly accurate watt meter with SWR plots and impedance. I personally don't worry that much about phase angle but if you add a phase detector for $18 then you have all you need for a pretty capable instrument.
If you take a look at the adl5519 datasheet they have the watt meter diagrammed. All you have to do is dive the signal programmatically from the DDS for sweep functions. I've played with it a little, mostly against tuned circuits. In my 'hood I have the worst BCI which means an untuned reflection bridge of any type won't work for antenna tuning. But from what I've tested the device seems to work perfectly and maps right agains my more expensive equipment, db to db. I measured it with a DDS driving a 50 ohm resistor to check the log linearity and it was within a 10th of a db when reading and calculating the db change using my DSO. -
As a ham radio operator i have concerns that too many features may make it confusing for some to use. It should have the ability to just be run as a simple antenna analyzer. Basic features for basic needs. Easy to use if you are not needing extra features. Perhaps a simple version firmware for those who just need basic functionality, and a more full featured version for those who need it.
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Hi cncjerry,
I think when you say impedance you mean module of impedance. If phase information is not captured then this is not a VNA, it is a scalar analyzer, antenna analyzer, SWR meter, power meter or something. Cannot be called impedance analyzer since it does not measure reactance. An AB meter cannot be called AB meter if it only measures A but does not measure B.
Same applies to the original poster's project - based on the information presented this device is not capable of displaying the sign of the impedance, which is still ok for variety of use cases but because it lacks this feature it is not a VNA. Also Antonio seems to be confused with meaning and use of dB and dBm units, may be Antonio could spend some time to learn a bit more about when to use one and the other.
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Why do they build those ICs like that? I don't see how determining the sign of the phase is all that hard.
PS. nm, I guess it's your own responsibility to have signal 90 degree phase shifted from your reference signals so you can disambiguate. -
Why do they build those ICs like that?
Because they were designed for RMS/log detection. It is just some people try using them for other purposes. -
Because they were designed for RMS/log detection. It is just some people try using them for other purposes.
I was talking about the phase detectors ... I don't get why they don't just go through a little effort to determine what the sign of the phase is, it's just a question of determining whether the rising edge of the second signal is on the high or low level of the other AFAICS. -
Hi guys I'm designing the new box enclosure
3D Box Enclusure
73'
IZ7LDG
info aferrulli@gmail.com
http://www.metrovna.it