Portsdown where?

Well,

As part of the project I mentioned last time, I've started to construct the hardware for the BATC Portsdown project.

The fist board I have tackled has been the LO filter. This goes post the AD4135 LO which uses the same development board as we used on the 4.4 GHz signal generator.

This is extreme, extreme soldering! I've invested in a flux pen of decent quality from Farnell and that's made my life much easier. Previously I was using some cheap eBay sourced flux which was a load of dingos kidneys.

Here's the results of my days soldering:




There's basically a 2 bit input thats status determines which of the three on board filters are in line (or bypassed on 23cm). I've tested this and can see three filters, not too sure about their shape though.

4M:


2M:


70cm:


23cm:


Looks a bit odd to me, but lets see.

Local conditions.