I decided to document my various microwave and millimeter wave projects and activity. In optical astronomy, a new telescope will capture its 'first light'. For uWave and mmWave, the first signal is captured by a new transverter to confirm the receive portion is working. So, it makes sense that the first entry is my weak signal source used for testing my transverters. It is based on a surplus Qualcomm phase locked oscillator board that is modified to generate a signal at 1152MHz. This signal is applied to a diode which generates harmonics for the ham microwave bands starting at 2.3 ghz and up. This particular board is described in great detail at the San Bernardino Microwave Society website (http://www.ham-radio.com/sbms/) under the link for the San Diego Microwave Society projects. This is a very useful item and it does allow me to do a quick field test on the receive portion of my system. Future entries will detail some of my new projects (and some old as well). This is all to get ready for the up coming microwave operating season in the spring and summer including the 10ghz and up contest in August and September.
In the photo, the PLL chip is in the lower left corner. The modifications included lifting programming pins, soldering new connections, and adding a capacitor to get the PLL to lock at 1152 MHz. The transmit signal path follows the left side of the board where MMIC chips amplify the PLL output to just around +10 dBM. That output is fed to an SMA connector in the upper right which as a very tiny surface mount diode soldered to the connector. The harmonics are of sufficient strength up to 10GHz although I have not heard any at 24GHz - possibly I need to increase the drive power to the diode to generate a signal up there.
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