SARK100 SWR Analyzer User Manual Revision 0.
SARK100 User Manual Contents 1 INTRODUCTION.......................................................................................................................4 1.1 REQUIRED TOOLS ................................................................................................................5 1.2 CREDITS ..............................................................................................................................6 2 TERMS AND CONDITIONS ............................................
SARK100 User Manual 10.6 INDUCTOR MEASUREMENT ..............................................................................................38 10.7 MEASURE INDUCTOR Q...................................................................................................39 10.8 TRANSMISSION LINE CHARACTERISTIC IMPEDANCE ...........................................................40 10.9 TRANSMISSION LINE LOSSES ...........................................................................................
SARK100 User Manual 1 Introduction The SARK100 SWR Analyzer is yet another antenna analyzer but available in kit form and designed to be easy to assemble and with an affordable pricing. You will enjoy of this DIY experience that it will not only help for improving your SMD soldering skills and learn about the analyzer basics but you will get a useful instrument for your shack.
SARK100 1.1 User Manual Required Tools PCB Assembly You will need the following tools to assemble the components to the board: Solder iron 25W (better if it has temperature control) and a moistened sponge Tweezers (recommended) Magnifying lamp (or magnifying glasses or loupe) Flat pliers and wire cutters Test equipment You will need the following equipment for the power-up and tests: DC Power source 13.
SARK100 User Manual Tools for building the overlay If you decide making the covers using the procedures described in this manual you will need the following: Inkjet printer Photo paper A4 size, preferably sticker type Transparent glue (in case of not using sticker paper) Cutter Rule Acrylic spray lacquer used for modeling or decoration Other The following components are not supplied with the kit but will be required for its operation: 8 Batteries NiMH 1000mAh capacity and AAA si
SARK100 User Manual 2 Terms and Conditions 1. The supply of the SARK100 is subject to the following Ordering Terms and Conditions: 2. This kit is an amateur project developed in my spare time, and so with no commercial support. You should be aware of this and accept as is; otherwise you will find in the market a variety of finished products or similar kits. 3. You should satisfy yourself whether the product meets your specific requirements, prior to placing an order.
SARK100 User Manual 3 Overview The SARK100 SWR Analyzer Kit is a measurement instrument which determines antenna system performance across the HF/6M amateur bands without the need of connecting the transmitter to the antenna. It is ideal for checking the resonance, bandwidth, and SWR in an easy and fast way. The meter also measures the resistance, reactance, and the magnitude of the impedance.
SARK100 User Manual The DDS, filter, and power amplifier form a sinusoidal signal generator which frequency and amplitude is controlled by the PSoC micro-controller. The amplitude control allows compensating the roll-off effect of the digital to analog converter in the DDS. The signal generator signal is delivered to the antenna through a reflectometer consisting of an absorptive SWR bridge using matched diode detectors and compensated buffer amplifiers.
SARK100 User Manual 4 Features Automated antenna SWR analyzer Supplied as an easy to assemble kit at an affordable cost Hardware: o Powerful and flexible PSoC microcontroller to control instrument operation o Precise and self-calibrating reflectometer design measures forward and reflected signals and impedance data o Display 2x16 with optional backlight o Precision DDS signal generator (AD9851) used as signal source o USB port connects to PC for field-upgradeable software and uploading
SARK100 User Manual Instrument Capabilities: o Measure antenna electrical parameters: SWR, impedance (resistance + reactance), capacitance, inductance o Measure feedpoint impedance o Measure ground loss o Adjust antenna tuners and determine loss o Measure inductors and capacitors o Measure coax transmission line (SWR, length, velocity factor, approximate Q and loss, resonant frequency, and impedance) o Measure and determine optimum settings for tuning stubs: SWR, approximate Q, resonant fr
SARK100 5 User Manual Specifications Frequency Generation & Control: o 1 - 60 Mhz o Source impedance: 50 Ohms o Stability: +/- 100 ppm o Spectral Purity: Harmonics down >- TBD dB beyond 60 MHz o Step Size: User configurable increments of 100 Hz, 1 kHz, 10 kHz, and 100 kHz Usable Measurement Range: o SWR: 1.0 to 9.99 o Impedance: approx. 5 to 2000 ohms RF Output: o Adjustable: 2.0 Volts pp (typ) Power supply: o External: 13.
SARK100 User Manual 6 Kit Contents The SARK100 kit consist of a double sided printed circuit board with silkscreen and solder mask, the components including the pre-programmed PSoC microcontroller, soldering supplies, and a suitable instrument box in grey colour (supplied without machining). Carefully review the contents of each parts bag and component supplied in the kit to ensure that you have everything needed at the start of the project.
SARK100 User Manual 47K R26,R32,R35,R38 49.9Ω R27,R28,R30,R9,R12, R13,R17 1M R29,R33,R36,R39 12Ω R43 10Ω R44 4.7K R52 10K R53,R54 470Ω R15 680Ω R16 100K R24,R25 220K R31,R34,R37,R40 2.7K R22 24Ω R14 Rev 0.
SARK100 User Manual SARK100 Parts List: Cantidad Referencia PCB Descripción Double-sided printed circuit board, including solder-mask and silkscreen SN FLUX WICK CASE SCREW CASE U4 OVL Thin solder wire Solder flux pen 1.5mm solder wick Grey ABS Enclosure with aluminium panels PCB Screws Pre-programmed CY8C29466-24PXI Drilling guide self-adhesive paper 1 LCD Display 2x16 with backlight 1 RT-50 Calibrating resistor 49.
SARK100 User Manual Cantidad Referencia R26,R32,R35,R38 R29,R33,R36,R39 R31,R34,R37,R40 R42 R43 R44 R53,R54 R52 R48,R49,R50,R51 SW1,SW2,SW3,SW4, SW5,SW6 SW7 U1 U2 U3 U5 U6 U8 U9 U10 U11 4 4 4 0 1 1 2 1 0 6 1 1 1 1 1 1 1 1 1 1 Descripción 47K 1M 220K DON’T ASSEMBLE 12 10 10K 4.
SARK100 User Manual 7 Assembly Guide The assembly of the kit consists of several stages. The first step is assembling the components on the printer circuit board. The assembly of the board is not as difficult as may seem at a first glance and can be performed without difficulty using the right tools. The complete assembly of the board should not take more than four hours. After this you will be ready for the power-up and tests phase.
SARK100 User Manual Bottom, “Controls” Side Left 7.2 7.2.1 Right Installing the surface mount components Preparation for the job The key to being successful with any construction project is selecting and using the proper tools. For projects using SMT (Surface Mount Technology), the tools are easy to find. A magnifying lamp (or magnifying glasses) is essential for well-lighted, close-up work on the components.
SARK100 User Manual A clean work surface is of paramount importance because SMT components often have a tendency to fly away even when held with the utmost care in tweezers – you’ll have the best chance of recovering your wayward part if your table is clear. When the inevitable happens, despite your best efforts of holding an SMT part in your tweezers, you’ll have lots of trouble finding it if it falls onto a rug-covered floor.
SARK100 User Manual mounted with the cathode pointing to the bottom of the board, i.e. pointing to SW7. The band indicator in C38 signals the positive polarity, marked with the '+' in the silkscreen. Figure 2, D1..D4 Orientation Figure 3, U3 Orientation Rev 0.
SARK100 User Manual Figuere 4, D5, D6, D7 Orientation Figure 5, C38 Orientation The solder technique is similar to the used for the ICs, apply solder flux to the component pads, pre-solder one of the pads on the board where the component will go, hold the component in place with tweezers on the tinned pad, reheat the tinned pad and component to reflow the solder onto the component lead, thus holding the component in place; and lastly solder the other end of the component to its pad.
SARK100 7.3 User Manual Installing the trough-hole components The assembly of the trough-hole components is quite easy and components can be assembled in any order, except the display connector JP1 and the pushbuttons SW1 to SW6 which have to be left to the end and mounted in the opposite board side. The components U6, U9, and U10 need a bit of preparation as it will be necessary bending the terminals with the aid of flat pliers.
SARK100 User Manual negative (black) of one of the supports should be soldered to the positive (red) from the other and then secure the connection with a piece of duct tape. Finally the spare positive (red) should be soldered to the board in the position marked as '+' from JP2. The spare terminal negative (black) shall be soldered to the 'GND' of JP2. . 7.
SARK100 User Manual Successively pressing the MODE button you can select one of the SARK100 operating modes: impedance (magnitude), complex impedance, capacitance, inductance, and off. If you connect a load or an antenna you will see the measurement results in the different ways. Leave impedance mode selected for the following tests.
SARK100 User Manual to the analyzer. If your PC has correctly identified the port you can run the HyperTerminal program on the PC and configure the port with settings: 57.600, 8, n, 1, and no hardware flow control. Once done you can start the connection on the PC side and in the analyzer side, select the "PC Link" option in the configuration menu. If all goes well it should appear in the HyperTerminal window a welcome text and a command prompt.
SARK100 User Manual You can start the job by drilling the holes for the pushbuttons using the handdrill and a 13mm spade drill bit. You should mark the center point of each of the drills, for example, by using the hot tip of the solder with the objective of directing the drill bit and holding it in place. The next step will be the cutout of the display rectangle. You will need drilling a hole to permit the passage of the blade of the fretsaw and then perform the cuts with precision following the pattern.
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SARK100 7.7 User Manual Manufacturing the Overlays Now it is time to improve the look of the instrument. This design gives the art design to create overlays for the front cover and optionally for the panels. You can either use this design as is or as a template to customize the design according to your personal taste. There are many techniques available to create the overlays or direct stamping the enclosure.
SARK100 User Manual Finally, carefully paste the overlays to the fron enclosure and the panels. The result must be like the following illustrations, with one sample with the box in gray and another in black. A good recommendation before making the whole process is to do a test print on plain paper, apply the cuts and see how it looks on the box. This will also serve as training and will make you sure that you are using the correct print settings and measures are being properly observed. Rev 0.
SARK100 User Manual 8 Connections and Controls Rev 0.
SARK100 User Manual 9 Antenna Analyzer Operation Power-on Power is turned on to the SARK100 by sliding the switch located on the bottom panel. After power-on the unit will display for half a second the following welcome message: SARK100 Analyzer (c) EA4FRB 10 V11 V11 indicates the unit firmware version. This information is important to check on the website of the project if there is a newer version.
SARK100 User Manual SWR 14,1 0.000 1.02 Z = 40Ω Pressing the left button will increase the digit value and, correspondingly, the signal generated by the unit. Pressing the right button will decrease the digit and the generated signal. When the digit is incremented past 9, or when it is decremented past 0, the digits above the selected adjustment point are rolled up or down, respectively.
SARK100 User Manual • The middle value is the resistance, i.e. the real part of the impedance, in this case 45 Ω • Then it is shown the reactance sign, ‘+’ for inductive reactance and ‘-‘ for capacitive reactance. If it is not shown, i.e. ‘ ‘ it means that it cannot be determined • Last term is the reactance, in this case it is 50 Ω inductive reactance This mode can not be used as a VFO because the frequency is continuously dizzling in order to determine the reactance sign.
SARK100 User Manual display as a bar graph. This will be useful to know if the antenna is receiving a near RF field which can interfere with the measurements. OFF BAND The BAND button allows selecting the working frequency band within the bands available. Pressing this button sequentially selects the next higher band which value is shown in the LCD, and it is changed the frequency. If it is the first time accessing the band, the frequency will be set to the middle value.
SARK100 User Manual frequency limit, in steps according the programmed step value. During the scan the SWR is measured and updated on the screen as well as the current frequency value. Each SWR value is compared to previous value in order to determine if a minima, or a “dip”, has occurred at this point in the scan. If so, that data point is stored for later display. Besides the 2:1 points are stored in order to determine the bandwidth.
SARK100 User Manual The available commands are described in Appendix H: These can be typed from the HyperTerminal window and the results will be returned to the terminal. The SARK100 will show the last processed command in the bottom line of the LCD. Step Size This function allows you to change the value of the frequency step for the SCAN and for the increase/decrease frequency buttons for the impedance measurement modes. Successively pressing the CONFIG button you can select one of the step values.
SARK100 User Manual 10 Uses for an Antenna Analyzer The SARK100 antenna analyzer is a useful tool for the amateur radio station or the homebrewer’s workbench. This section will describe the basic uses, as well some advanced techniques for which you can use the analyzer to get intermediate measurements in order to compute the desired result. 10.1 Antenna Measurements The antenna is simply connected to the analyzer RF output and the analyzer is set to the desired frequency.
SARK100 User Manual Another way to measure capacitance with the SARK100 is to measure it in a series resonant circuit. (See Figure 6 and Figure 10). You will need an inductor of known value and a 51 Ω carbon composition or film resistor. It is recommended that a small 5% tolerance choke with an inductance of between 1 and 10 uH be used. Common RF chokes are fine and can be obtained from most full-service mail order component suppliers.
SARK100 User Manual To measure inductance by the second method, connect the components as shown in as Figure 6. Adjust the operating frequency for lowest SWR and record the frequency. Now you can calculate the capacitance using the formula: L= 25530 F × F ×C Where L is the inductance in microhenries, F is the frequency in MHz and C is the capacitance in picofarads. 10.7 Measure Inductor Q The Q of an RF inductor can be measured with a very simple setup.
SARK100 User Manual 10.8 Transmission line characteristic impedance The characteristic impedance of coaxial, twisted pair, open wire or ribbon type feedlines can be estimated using the SARK100. Practical measurements are best done in the mid-tuning range of the instrument where accuracy is optimum and feedline lengths are reasonable; so this procedure will be performed between 7 and 21 MHz.
SARK100 User Manual Approx Loss Measured SWR 1 dB 9:1 2 dB 4.5:1 3 dB 3:1 4 dB 2.3:1 5 dB 2:1 6 dB 1.7:1 7 dB 1.6:1 8 dB 1.5:1 9 dB 1.4:1 10 dB 1.3:1 10.10 Transmission line stub lengths Measurement of quarter and half wave transmission line stubs can be performed regardless of the transmission line characteristic impedance.
SARK100 User Manual To determine the length of a half wave stub, connect the near end of the transmission line through a 51 Ω resistor as shown in Figure 9 to the analyzer’s RF output connector. Short circuit the two leads at the far end of the half wave stub. Ensure that the transmission line is supported for its entire length in a fairly straight line and kept several inches from any conductive surface or material. This is important to minimize any detuning effects.
SARK100 User Manual Figure 8, Adjust antenna tuners Figure 9, Determining length of a halfwave stub 25330 C= F2 x L 25330 L= 51 Ω F2 x C C in pF L in uH F in Mhz Adjust freq “F” for lowest SWR Figure 10, Capacitor or inductor measurement Rev 0.
SARK100 User Manual Figure 11, Determining feedline characteristic impedance Figure 12, Determining feedline velocity factor Rev 0.
SARK100 User Manual 11 PC Software The SARK100 is controllable from the PC and allows the collection of measurements to be processed by an analysis program. In the project website you can find a simple command line program, PCC-SARK100, which performs control and data capture from the SARK100 and generates a data file compatible with Excel macro ZPlots from Dan Maguire AC6LA. This macro performs the analysis of the measures and displays them in different graphs.
SARK100 User Manual Rs / Xs vs Frequency 500 120 450 100 400 350 80 250 60 Xs Rs 300 200 40 150 100 20 50 0 0 13 13.2 13.4 13.6 13.8 14 14.2 14.4 14.6 14.8 15 Frequency (MHz) Rev 0.
SARK100 User Manual 12 PSoC Development One of the advantages of SARK100 analyzer is that the software is fully upgradeable via USB, the code is open and programmed in language 'C', and also the programming tool "PSoC Designer” is free so you can fully customize the operation of the instrument. Note that the software is available for download on SourceForge and you can participate as a developer in the project and contribute to improving the product.
SARK100 User Manual 4. Modify the text with your callsign and click the save button, for example:: BYTE const gWelcome2Str [] = "(c)XYabc 10 " VERSION_STR; Figure 13, PSoC Designer 5. In the "Build" menu, select the option Build 'SARK100_SwrAnalyzer_BL' Project. You can also invoke this function by pressing F7. 6. If all went well in the window "Output" will indicate that the project has been compiled without errors 7. The downloadable file .\SARK100_SwrAnalyzer_BL will be available and has the
SARK100 User Manual 13 Troubleshooting This section is a guide to the event that the instrument does not work as expected after the assembly. You will need some basic tools and the schematics and layout of the board available in the appendices of this manual. In any case, first of all I recommend that you inspect the assembly and soldering carefully. The board is relatively simple so it is easy to review thoroughly to discover any bad soldering or short circuit.
SARK100 User Manual Using the multimeter and making sure that the switch SW7 is in the OFF position, check the voltage on the cathode of D5 or D6. If there is not any voltage, the problem might be an incorrect position of D5 or D6, or a failure of U11 though the latter would be quite unlikely. If that's OK, put the switch SW7 in the ON position and measure with the multimeter U6 the regulator output, i.e. the pin 2.
SARK100 User Manual Problem The display shows no message Solution If the PC does not detect the device it may be an assembly error of the USB chip (U8). Check the solders because it is a fine pitch component and could have been a bad soldier terminal or shorted. First check that all board supplies are correct including the display supply. One possible cause is that the PSoC microcontroller is not programmed correctly or lost the programming, for example, after an interrupted software update.
SARK100 User Manual 14 Theory of Operation – Hardware Referring to the schematics (Appendix A:), a block by block description is presented in this section. DDS Signal Generation The sinusoidal signal generation is done by means of the integrated circuit AD9851 from Analog Devices that includes the DDS synthesis and a 10-bit digital-analog converter. The reference clock is supplied externally by a 30 Mhz oscillator which is multiplied by six internally by the DDS for a 180 Mhz working frequency.
SARK100 User Manual This is connected to an analog output of the PSoC microcontroller so that you can perform DDS amplitude under software control. This is used in this project to compensate for amplitude roll-off with frequency DDS. Also thanks to the programmable features of the PSoC it would be possible implementing amplitude modulation with low-frequency signals but this quality will not be used for this project.
SARK100 User Manual The operating voltage of the micro-controller is 5V and the clock frequency of the CPU is programmed to the maximum frequency, i.e. at 24 Mhz.
SARK100 User Manual Power Supply The design integrates a sort of regulators to allow operation from both battery and external power supply and also implements a battery charger. The battery consists of 8-cell AAA format NiMH 1000 mAh capacity in series, for which the nominal voltage is 9.6 V. The battery charger is constant current type and has no control of end of charge so it has been designed to load below 0.1 C (100mA) to avoid the damaging the battery.
SARK100 User Manual stage compensates the nonlinearity of the transfer curve of the diode, thus improving the accuracy of measurements. Furthermore, this design uses paired diodes which improves accuracy. The diodes, HSMS-2805 Avago Technologies, has been selected with a breakdown voltage of 70V to provide better reliability.
SARK100 User Manual 15 Theory of Operation – Software The operation of the SARK100 is completely software controlled and the software running on the PSoC micro-controller. The program has been fully developed in ‘C’ language and it is open source so you can study it in detail and modify and evolve it at your convenience. The program also includes a bootloader that allows field upgrades trough the USB connection.
SARK100 User Manual Este módulo proporciona las rutinas de cálculo de ROE, Z, R, X, L, y C; utilizando los resultados de las medidas del convertidor analógico digital. The used formula are the following: ROE = VF + VR × 100 VF − VR Z = 50 × R= VZ VA (2500 + Z 2 ) × ROE 50 × ( SWR 2 + 1) X = Z 2 − R2 10 6 × X L= 2 × pi × F C= 1012 2 × pi × F × X φ = a tan( X 180 )× (not yet implemented) R pi The sign of the reactance is determined by a frequency shift technique.
SARK100 User Manual Measure.c This is the driver of the analog to digital converter and so where the legs measurements are performed. For each bridge leg it is selected the right multiplexer input, it is adjusted the gain of the input amplifier, and then it is performed an acquisition of the analog to digital converter. For the measurement it is implemented the “Correlated Double Sampling” technique that consists in taking a dummy measurement with the input shorted and then perform the real measurement.
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SARK100 User Manual Appendix B: Quantity 19 2 1 6 1 4 4 1 4 3 1 1 1 1 1 2 2 1 2 7 3 1 1 1 1 2 4 4 4 1 1 2 1 6 1 1 1 1 1 1 1 1 1 1 1 Part List Reference C1, C2, C3, C4, C5, C6, C7, C8, C14, C15, C16, C17, C27, C28, C31, C35, C37, C40 C9,C10 C11 C12,C30, C19, C22, C21,C25 C13 C18,C29,C36,C39 C20,C23,C24,C26 C38 D1,D2,D3,D4 D5,D6,D7 JP1 J1 J2 J3 LS1 L1,L2 Q2,Q3 R3 R8,R4 R9,R12,R13,R27,R28,R30,R17 R10,R11,R18 R14 R15 R16 R22 R25,R24 R26,R32,R35,R38 R29,R33,R36,R39 R31,R34,R37,R40 R43 R44 R53,R54 R52 SW1,SW
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SARK100 Appendix E: User Manual USB Driver Installation The SARK100 incorporates a USB interface for PC connection. This interface is implemented by the FTDI Chip FT232R chip which requires prior installation of a driver "Virtual COM Port (VCP) available at the following link: http://www.ftdichip.com/Drivers/VCP.htm This driver is available for multiple operating systems on which you access the manufacturer's website and select the appropriate driver, always bearing in mind that the chip is the FT232R.
SARK100 Appendix F: User Manual Updating the Analyzer Software The analyzer software is upgradeable via USB, so the analyzer can be updated with the latest software available on the website of the product, or you can even customize the code by using the free PSoC Designer tool. For the software update will need a PC running Windows and a USB cable (not included). The loading program: TerminalProgram_v2.zip is available on the project website.
SARK100 User Manual 5. Select the communication port, in this example COM6, from the drop-down list on the right. Pressing the button [Select HEX File] and select the file to load, in this example SARK100_SwrAnalyzer_BL.hex. Finally check the tab "Wait for connection with PSoC”. At this time the program is ready for synchronization with the SARK100. The resulting screen in this state is as follows: 6. Now in the SARK100 go the CONF menu and select the option "Load Software" and click VAL.
SARK100 Appendix G: User Manual Calibrating the Analyzer To improve the accuracy of the analyzer this should be calibrated. This is a simple procedure that just requires loads of known value and follows the outlined procedures. The calibration data is stored in nonvolatile memory and will remain stored during the life of the instrument. Recalibration will be necessary in the case of a software update because the stored calibration data are lost during the loading process.
SARK100 User Manual 5. Subsequently it will prompt to connect a 274 Ω load “Conn 274 Ω Load”. Plug the 274 Ω load and then press VAL. The display will show “In Progress…” indication that calibration is in progress 6. Once the calibration is finished it will show the text “Done”. This means that the calibration process has been completed and stored in the EEPROM. Just press VAL to continue Rev 0.
SARK100 User Manual Appendix H: Making a Dummy Antenna for Testing It may be desirable to have a dummy antenna for testing the SARK100. A dummy antenna is simply a three-component circuit that is resonant at a specific frequency and has a purely resistive characteristic at the resonance frequency. The dummy antenna can be used in place of a real antenna during initial testing of the instrument.
SARK100 Appendix I: User Manual PC Command Interface Command On Description Enables DDS signal generation.
SARK100 User Manual Command imp Description Get impedance values Arguments -- Response {SWR},{R},{X},{Z} Error response -- Example >>imp 1.05,52,10,51 Command raw Description Get raw bridge voltages Arguments -- Response {Vf},{Vr},{Vz},{Va} Error response -- Example >>raw 257300,165500,31800,214500 Rev 0.
SARK100 User Manual Command scan Description Scans from specified start to end frequency and get impedance values Arguments {freq_start} Start freq. in Hz {freq_end} End freq. in Hz {step} Step in Hz Response Start {SWR},{R},{X},{Z} {SWR},{R},{X},{Z} … End Error response Example Error: expected freq val Error: expected step val >>scan Start 1.05,52,10,51 1.05,52,10,51 .. End Rev 0.
SARK100 User Manual Command Scanr Description Scans from specified start to end frequency and get raw bridge voltages Arguments {freq_start} Start freq. in Hz {freq_end} End freq. in Hz {step} Step in Hz Response Start {Vf},{Vr},{Vz},{Va} {Vf},{Vr},{Vz},{Va} … End Error response Example Error: expected freq val Error: expected step val >>scan Start 257300,165500,31800,214500 257300,165500,31800,214500 … End Rev 0.
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