Clickety Clack of the Relays

Slowly integrating all these bits together in software and currently all the relays are clicking in sequence when I change bands on the control board. If you look closely on the upper right, you will see an updated version of the Band Pass Filter board that uses different inductors and filter topology. I need to populate and test one filter to ensure its right and then build the entire board.

Something that I did not notice was that when I changed Ecad software my mounting hole pattern has changed slightly, so neither of the old filter board designs will stack with the other boards. So i have to redo the low pass filter board and I am going to redo the rf frond end board as well and move things around to make it a little more usable and to make sure the 3.3v regulator has a heatsink on it. With bugger all current running though it, it still gets burn your finger hot and that is not right. I am starting to wonder if these ebay parts are actually dodgy or something.


Receiver RF Front End

VK4FFAB Receiver Front End

Ok, I am posting this mostly because I can, but I wont publish the gerbers yet because I actually want to layout the board better, fix some footprints and have the boards remade. Not because they are bad or do not work, but because I know i can make them so much better

So this it my receiver front end. RF comes in from the antenna, through the TX-RX relay into a 0-31dB attenuator module, into a 5 to 15dB RF Preamp.

The RF amp is a pair of J310 as a dual gate mosfet as designed by Pete Juliano here: SimpleCeiver

Variable RF Preamp Schematic
Prototype Built and Tested
PCB as originally laid out.

I might add some more info here later, or will just post anew when i have redesigned the board. The main thing i want to do is to remove those wire links joining the attenuator to the rest of the circuit and replace that with some right angled SMA connectors as the attenuator board comes with SMA connectors on it already. I will probably change the relay also as I now have some better RF relays, not just chinesium grade floor sweepings.