A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje November 9, 2014
A 2.4GHz to 1.5 GHz down converter layout

This is basically a VCO, mixer, and voltage stabilizer:

The screw in the trimpot will allow fine adjustment of the output frequency from outside the box.

After using this 964 MHz VCO in several projects,
finally a pad (VCO in) broke off.
Had to open it...
removed the cover:

This time I did take a picture of the internals:

The little 3 turn coils is the main oscillator.
The big SMD is a varicap I think.
There is only one transistor, active component..
And a mysterious zig zag coupling to the 50 Ohm output on the left.

 BTW: their 2.4 GHz VCO coil only has 2 turns.

So now you know how to make your own...

The LM317 makes an excellent voltage stabilizer.
Now need to solder that cap back on, and add come capacitators and resisisters.

As this is only a 'monitor',
to check what I am sending upwards towards the sky (satellite),
and that will be many Watts, there is no need for any gain.

The output goes into the DVB-S satellite receiver's LNB input.
Any cheap WiFi antenna will do for the input.

It so happens the VCO output is just the right level for this mini-circuits ring diode mixer.

Of course all still has to be tested, I am using that mixer out of spec.