Quick Experiment With the LO Module and Some Chinese Modules. 2.4GHz signal achieved.

 Today I got a quick set-up to see how some of the modules I have could be used as a transverter or up-converter from 432MHz to 2400MHz.

Here are the parts:

- the 2009MHz oscillator module I tested a few days ago

- a mixer PCB module, IF DC-1.5GHz, RF/LO 1.5-4.5GHz

- a 2.4GHz filter PCB module using "hairpin" resonators

- a Wilkinson combiner/divider hybrid PCB module

All this was just lying loose on the lab desk, connected with SMA cables with the first port to the 35-4400MHz spectrum analyzer and the second port of the hybrid terminated with a 50 Ohm load. The second port is intended for use in 2.4GHZ reception

For the test I set my signal generator to a 391MHz IF, mixing with 2009MHz to get 2400MHz out.

The raw signal out of the mixer was as expected, a bit of 2009MHz LO feed through with LO +/- IF signals about 30dB stronger

Adding the filter (and the hybrid) provided a solid signal on 2400MHz. The LO signal was about 45dB down, and the image frequency was about 55dB down.

The results are encouraging. I would expect the stray LO and image signals would be better attenuated when the mixer/filter/hybrid  modules are mounted in a shielded casing, but for the transmitter path I intend to mount a second filter between some of the amplifier stages, in a second shielded casing.

For a receive path in a transverter A second filter is probably also a good idea, but at present it may not be necessary. In principle this is a very low powered and very insensitive 391/2400MHz transverter.

What comes next (in no particular order)?

- modifying the LO module to generate 1968MHz, so a 432MHz  can be used as the IF.

- building an amplifier chain, so I can get a minimum of about 500-800mW output.

- building the modules into shielded casings Except the LO, it is already in an excellent shielded box.

- Start mounting this arrangement into a sufficiently large casing

- adding circuitry for supplying and controlling the LNB used for QO100 reception. Right now the QO100 set-up has separate transmitter and receiver.

- adding receive amplification/filtering for 2.4GHz.

- adding control circuits, such as T/R switching, band switching etc.

- adding a second down converter, so the LNB's IF signal can be received on 144 or 139MHz

- maybe a bit more when I can think of it.