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Product Description
  • Features: 

    AD9850 0~55MHz DDS Signal Generator For HAM Radio VFO SSB RIT 6 Bands



    • This is a 0~55MHz (latest version, firmware updated in 2013) DDS Signal Generator. It is based on AD9850 chip and is very easy to operate.
    • Supports 0~55MHz continual adjust at 1Hz step.

    • This generator has 78L05 voltage regulate. Input current at 200MA, input voltage 8-9V would be the ideal voltage.

    • Input voltage of 12V can only be used for short time testing, otherwise will cause heat to board.

    • 5p/6p connect to encoder as per photo. 7p of the middle connects to digital matrix input. 14p (8V GND) is 8V power supply from main board. If powered by main board, DDS does not need independent power supply.

    • 1~6 correspond to 6 frequency bands: (3.87 91418 or 2127 or 29)

    • ISB, USB, CW are the three mode choices.

    • DT is signal from main board


    Connection of external key:
    The KB-2 and KB-1 are the external key interfaces, and the leftmost feet of them are the common pins of the respective interfaces. They are connected with the four pins of the respective interfaces to complete their functions, such as KB-1: 1 -2 connected to complete the control mode conversion mode, such as KB-1: 1-4 connected to enter the adjustment of the state step.
      The ENC in the above figure is the foot of the coding switch, in which the A of the following figure is connected with the 2nd pin of KB-2, the B of the figure is connected to the 3rd pin of KB-2, 1 foot.
    7, on the work mode and band control
       Due to the limited driving capability of the MCU itself, or the working voltage of the external relay is different, it is not possible to drive the relay directly. The external drive circuit is required for the operation mode and the operation band. Refer to other information for the specific circuit.
    8, LCD backlight connection
      Taking into account some friends may use their own configuration of the LCD screen, LED backlight may be different because of the polarity, so in the PCB, the 15,16 feet are vacant, please use the LCD polarity according to their own connection.
      I provide the LCD backlight connection, 16 feet grounded, 15 feet in series with a 51 ohm resistor connected to the power + 5V just fine, if you want to turn off the backlight at any time, you can take a switch on the +5 V control.
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    Second, DDS debugging
    The DDS control chip PIC16F628A-1 and PIC16F628A-2 have written VER4.06 program, after all the installation is complete, access 5V power supply, adjust the contrast of the 10K potentiometer, under normal circumstances can be seen on the screen Character, if not normal, please measure the MCU and display part of the operating voltage. This setting has voltage polarity protection, so it will not burn your chip situation.
    If the LCD can not display characters, please try to swap PIC16F628A, because the two chips in the program is different, in accordance with the components marked on the number of installation.
    Third, DDS button instructions and steps:
    1, the key interface description:
        ENC coding switch pin
    MEM memory mode conversion
    VFO VFO A to VFO B, or VFO B to VFO A.
    SSB operating mode conversion, USB LSB AM CW cyclic conversion.
    RIT Adjusts the receive frequency.
    STEP Step adjustment button.
    CAL function setting button.
    KB-1 and KB-2 which have a common pin, but not ground, please pay attention when installing.
      3, hold down the CAL button, power-on boot into the initial setup interface, and release the CAL button.
    A: ENABLE 6XREFCLE: Set the chip clock mode, adjust the frequency encoding switch settings, AD9851 is set to 6 multiplier, AD9850 set to 1 octave, press CAL to enter the next item.
    B: DDS-SYSTEM-CLK: chip operating frequency settings, adjust the coding switch to change the value, with the STEP key to adjust the step, AD9851 is set to 6 times the value of the active clock oscillation, AD9850 set to the source clock oscillation of the actual output Value, press CAL to enter the next item.
    C: MIN_RX_DDS_FREQ: The minimum operating frequency setting, adjust the coding switch to change the value, with the STEP key to adjust the step, should be set to greater than the IF value, press CAL to enter the next item.
    D: MAX_RX_DDS_FREQ: the maximum operating frequency setting, adjust the coding switch to change the value, with the STEP key to adjust the step, should be set to 60MHZ the following can be short press CAL to enter the next item.
    E: SSB_OFFSET: SSB work mode fine-tuning, adjust the coding switch to change the value, with the STEP key to adjust the step, press CAL to enter the next item.
    F: CW_OFFSET: CW work mode fine adjustment, adjust the code switch to change the value, with the STEP key to adjust the step, press CAL to enter the next item.
    G: OFFSET_FREQ: IF setting, such as set to 9MHZ or 10.7MHZ, adjust the coding switch to change the value, with the STEP key to adjust the step, press CAL to enter the next item.
    H: MULTIPLIER: multiplier setting, should be set to 1, press CAL to enter the next item.
    I: the display will prompt SAVE, automatically save the contents of the above temples, and returned to normal working condition.
    Other notes:
    1, DDS SYSTEM CLK frequency meter can be measured with 30MHZ active crystal, the measured value multiplied by 6, the calculated value set here, if you use the AD9851, the initial set to 180000000 on the line.
    2, OFFSET FREQ IF setting, can be set to + or -, rotary encoder switch to change the value, hold down the STEP button, then rotate the encoder switch to adjust the step. In addition the minimum operating frequency plus the value of the IF must be greater than 0.
       ** Frequency Storage **
    To store the current VFO frequency: Press and hold the MEM button for at least 1 second. Use the encoder to select the channel you want to store. While selecting, the selected channel original frequency will be displayed on the LCD. At this time, press the MEM button again for more than 1 second, and a message "SAVING" will be displayed briefly while returning the VFO display. (Stored) If you decide to return to the VFO display or not, press the MEM key or wait for 10 seconds to return automatically. Before using the memory function, make sure that all parameter settings are correct. This will prevent incorrect information from being written to the channel.
       ** Use Memory Channel **
    When shifting from the VFO state to the MEM state, the encoder may select the previously stored reception frequency,
    Press the MEM button and MEM 1 will be displayed at the top of the LCD. You can use the encoder to select the channel you want to use. When the TX and RPT buttons are in the MEM mode, you can not change the frequency with the encoder. RIT function is normal. (RIT frequencies can be changed using encoders). When in MEM mode, you can not use the setup menu or the frequency memory function.
       In operation, the setup menu will check the correctness of the memory. If the error message is displayed, the "MEM" display changes to "---", which is caused when you change some of the parameters in the setup menu. And then try to store the previous changes. If you try to use MEM 1, the setup menu will find a 30 M reception frequency error, since the frequency of the RX RX DDS FREQ is reduced to 29 M, It is too high), so the correct approach is to store the function before the correct menu settings.
       There are two ways to exit MEM mode and return to VFO mode:
    1) Press the MEM key, ignoring the memory frequency used.
    2) Hold down the MEM key for one second and the correct frequency will be copied to the VFO.
            ** Menu settings storage **
    Any changes to the menu settings will be stored in the EEPROM after MULTIPLIER is set, and the "SAVING" message will be briefly displayed and the VFO status will be returned.
    In the setup menu (except for the DDS REF FREQ menu), the screen ignores all actions and returns to the VFO display if the keypad, keypad, or encoder does not act for 10 seconds.
    If RIT is pressed, RIT will be displayed on the LCD, but its frequency will not change very much (range RX frequency +/- MAX_RIT_OFFSET frequency). Pressing the RIT button again will deactivate the RIT display. And returns the RX frequency, while clearing the RIT frequency change.
    If RPT (REPEATER TX offset is only used for FM) is enabled in the setup menu, tap RPT to display "-RPT" on the LCD and subtract (RPT OFFSET) frequencies from the TX frequency. Press again to clear the RPT setting. The default REPEATER TX OFFSET is 0KHZ, but it can be changed in the setup menu RPT OFFSET, ranging from 0 to 10MHZ. (Also limited since the DDS should leave a frequency of 0 to MAX DDS FREQ)
    If the RPT function is set to disabled, the RPT function is disabled, and the RPT setting frequency is automatically set to 0 Hz.
    All settings will affect the frequency limit range, and confirm that the setting is valid, for example: TX offset plus RX frequency can not exceed the DDS frequency range.
    If the step button is pressed, a cursor will flash under the current frequency number, in which case the encoder selection step can be used.
    For example, to move 1KHZ, move the cursor to release, and the change will be in 1K steps. (If the rotation is too fast, the system will detect it, and the setting may remain unchanged.)
    Any step settings in the VFO state are stored in the EEPROM. (Not stored in the menu settings and RIT settings)
    The frequency display will follow the formula:
    The frequency programmed into the DDS, is calculated as shown below.
    Can be positive or negative.
    Here are a few different examples:
    Such as DDS output frequency range of 30M to 40M:
     MIN_RX_DDS_FREQ MAX_RX_DDS_FREQ OFFSET_FREQ RX Frequency display range.
      30 MHZ 40 MHz 100 MHz = 130 MHz to 140 MHz. \\ Note 1
      30 MHZ 40 MHz -10 MHz = 20 MHz to 30 MHz. /
     -40 MHZ -30 MHz 170 MHz = 140 MHz to 130 MHz. \\ Note 2
     -40 MHz to 30 MHz 60 MHz = 30 MHz to 20 MHz. /
    The FT180A uses the DDS setting method
    Display AD9851 general settings explained:
    X6 RECLK X6
    MIN RX DDS FREQ 10.701M IF frequency + RIT frequency
    MAX RIT OFFSET 1K RIT frequency
    OFFSET FREQ -10.700M - IF frequency

  • Package Contents 

    100% Brand New
    1 x AD9850 0~55MHz DDS Signal Generator For HAM Radio VFO SSB RIT 6 Bands

Packaging Details
  • Unit Type: piece
  • Package Weight: 0.25kg (0.55lb.)
  • Package Size: 8cm x 8cm x 8cm (3.15in x 3.15in x 3.15in)
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Packaging Details
  • Unit Type: piece
  • Package Weight: 0.25kg (0.55lb.)
  • Package Size: 8cm x 8cm x 8cm (3.15in x 3.15in x 3.15in)
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