Sunday, June 23, 2013
In my case the problem was the metallic enclosure used for the transverter. With the cover removed everything was fine but once the cover was put in its place, the local oscillator was present at the output at nearly 5mW of power: Just unacceptable.
Wednesday, June 12, 2013
Because the design frequency of the module is 10.4 to 11.7 GHz, it works unmodified at 10368 MHz, which is a clear advantage for use at ham radio.
There is not too much information about these modules except the info published by G8CUB here and here, this post from M0DTS and this datasheet. It is convenient to read all these documents before continue reading this post.
Friday, June 7, 2013
When supplied at 13.8 volts, high output power should be 1W, but I was measuring around 550mW. Clearly something was wrong. Many time ago, when I purchased the walkie, I did a quick readjustment using an attenuator and a spectrum analyzer. Spectrum analyzers are fine to see spurs or relationships between carrier and harmonics but they are not good as absolute power meters, specially if you are using them at the top of their dynamic range, this is with insufficient attenuation between.