14 May 2017

10 GHz TX ready for the first mission

Now that I have completed, debugged and tested the WFM modulator for HB100 radar modules, it is time to try an outdoor transmission. Since I will place the transmitter at my parent's place I needed an enclosure.

Peter PA1SDB (probably him) measured the attenuation of various materials, and plastic was found to introduce negligible attenuation at 10 GHz. So I bought a plastic box for food at the Chinese shop around the corner (1.19€) and this is the first result:

I love working with plastic because most of the time it can be drilled by hand. So far I have secured the HB100 module (TX only), while the breadboard is a tight fit in there.

The modulator is based on DJ7OO circuit and was built with parts that were in the junk/parts box. Main difference is that the tone generator is built around a NE555 and potentiometer P2 on the voice chain has been connected properly. The NE555 might be replaced with a microcontroller so that more functions can be executed, like bitonal beacon and MCW ID.

What's missing before the test in the outside world is a DC socket and a power switch. Then a beacon/voice toggle and a microphone input too.
The test transmission is scheduled for Tuesday.