Sark-110 Antenna Analyser

In the PO Box the other day was a new toy. (this one is my birthday present to myself) 😀

IMG_1547 IMG_1609

I had been using a you kits FG-01 for a and while and that device worked well, BUT…  it lacked some functions and stopped at 60Mhz. I had read and seen a lot about the little sark-110 unit, and decided to offer the you kits for sale and upgrade. So with the FG01 disposed off, an order for the sark was placed and a couple of days later it arrived.

The sark is basically a screen/box thats smaller than an iPhone, its a small screen with a USB plug on one end and a MMCX connector on the other side.

The device is very powerful! the list of features and functions is best seen on the device product website. It can be used to measure Complex impedance (series and parallel) and reflection coefficient in rectangular and polar form, VSWR, return loss, reflection power percentage, quality factor, equivalent capacitance, equivalent inductance. It has the ability to connect to some partner windows software and have this information driven from a computer as well.

Its very easy to use, plug it in, dial up the required range and press go, the screen comes back with the required information, you can use the preset ranges as well, or plug into the computer and do some other analysis. The device can also take screen shots in the field, you also have the ability to export the data as a .CSV file to plot later, it does Circular (smith chart) plots also. Its very powerful!

144mhz via triplexer

My 144Mhz vertical VSWR plot

IMG_1682OCFdipole-homesark_ocfdipole sark_TDR_mode OCFdipole-home

The OCF dipole at home (on sark and via software)

sark_TDR_mode

The TDR mode (this isn’t ideal – measuring the coax on OCF dipole – 18m correct!)

sark_000 sark_001all sark_003 sark_004 sark_006 sark_001

some direct device screenshots

The developer is very active with firmware updates and development of the device is ongoing with new features and functions added frequently.

The TDR function is of interest to me, and as part of this, I am building up a set of calibration tools following the notes at IN3OTD’s (and from others) websites. When the bits required to make these up arrive, ill post a blog about their construction.

The device is really is beyond my current requirement, however, it should allow a lot of tinkering and antenna development into the future, and I do like to tinker..

Specifications

Synthesizer

·       Direct Digital Synthesis with 1Hz resolution

·       Sine wave output

·       Frequency range from 0.1 to 230Mhz

Measured Parameters

Complex impedance (series and parallel) and reflection coefficient in rectangular and polar form, VSWR, return loss, reflection power percentage, quality factor, equivalent capacitance, equivalent inductance

Operating Modes

Scalar Chart, Smith Chart, Single Frequency, Cable Test (TDR), Field, Multi-band, Signal Generator, Computer Control

Features Common to Most Modes

·       Presets for amateur radio bands

·       Adjustable reference impedance

·       Save to disk and recall functions

·       Three available fixed scale options and automatic scaling

·       Presets for popular coaxial cables

·       Add/subtract transmission line

·       Black or white color schemes

·       Adjustable plot trace widths

Scalar Chart Mode

·       Graphical plot of two user-selected parameters in a rectangular chart

·       Two markers with manual or automatic positioning

·       Display detailed parameters for center frequency or any of the two marker positions

Smith Chart Mode

·       Plots complex reflection coefficient in Smith Chart form

·       Two markers with manual or automatic positioning

·       Display detailed parameters for center frequency or either of the two marker positions

Single Frequency Mode

·       Display all parameters for a single frequency

·       Graphical representation of series and parallel impedance equivalent

·       VSWR Audio feedback

Cable Test Mode

·       Maximum length: about 250 m

·       Displays step and impulse responses

Field Mode

·       Graphical plot of one user-selected parameter in a scalar chart with enhanced legibility

·       Display max and min values

Multi-band Mode

·       Display rectangular charts for four bands simultaneously

Signal Generator Mode

·       Precise RF signal generator with 1 Hz resolution

·       Programmable output level from -73 dBm to -10 dBm

·       Continuous and frequency sweep modes

·       Linear, logarithmic, bi-linear, and bi-logarithmic sweep modes

Markers

·       Tracking modes:

o        Peak Min

o        Peak Max

o        Absolute Min

o        Absolute Max

o        Value Cross Any

o        Value Cross Up

o        Value Cross Down

Interface

·       Full color 3” TFT LCD 400 x 240

·       4 dedicated buttons

·       2 navigation keys

·       MCX antenna socket

PC Interface

·       USB Mini-B receptacle

·       USB 2.0 Full Speed

·       USB Composite Device:

o        Mass Storage Class (internal disk)

o        HID Class (Computer Control mode)

Storage

·       2 MB internal disk FAT compatible

·       USB Mass Storage

·       Screenshot save and recall feature

·       Measurement data save and recall feature

·       Possibility of files with user definable frequency presets, scale settings, and three custom cable types

·       Measurement data files compatible with SARK Plots and ZPLOTS programs

Calibration

·       Automated Open/Short/Load calibration

·       256 calibration points

·       Calibration settings stored on disk

·       Frequency calibration

Measurement Architecture

·       Single conversion super heterodyne

·       Two independent measurement channels for simultaneous voltage and current measurement for precise phase measurement

·       Two synchronized 12-bit analog to digital converters

Processor

·       72 MHz STM32 MCU

·       256KB Flash

·       48KB SRAM

RF Output

·       Connector: MCX socket

·       Output power: »-10 dBm (0.1mW, 70.7mV rms) into a 50-ohm load

Power

·       3.7V 1000mAh Internal Lithium-Polymer battery

·       USB for operation and charging

·       Automatic Power Off functionality (disabled, 5, 10, or 30minutes)

·       Autonomy » 2.5 hours

·       Charge time » 3.5 hours

Environment

·       Operating temperature: 0ºC to 50ºC

Dimensions

98 * 60 * 14.5 (mm)

Weight

300g

Package Content

·       SARK-110 x 1

·       Battery x 1

·       MCX to BNC adapter pigtail x 1

·       Allen key x 1

4 thoughts on “Sark-110 Antenna Analyser

  1. Pingback: Strange link dipole shenanigans? - VK3BQ

  2. Can I use my MAC and its OS X to obtain and install new microcode into the Sark rather than a PC? Thanks

    • The sark looks like an external hard drive device on pc or Mac. You just download the new firmware and copy this file onto the device and then run the firmware upgrade from the dark. Yes. It works on a Mac. Thanks

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