Active Ferrite Aerial Project

[Geaney]

I've finally found some time to get back to this project. When I switch the device on, there is a noticeable improvement in the quality of reception using one of the Radialva sets as the test radio. However, none of the tuning/Q controls seem to do anything.

As I'm not familiar with varicap tuning or the details of how dual gate FET's etc. work, I'd appreciate any guidance regarding how to establish if the varicap diode is working or how to check the circuit in general. The output pot certainly works and the quality of reception improves as the output is increased. The noise level also reduces as output is increased - which is especially welcome.

I went down a bit of a hole with regard to the FET. I used the component tester that many of us bought on eBay which seemed to indicate that the component layout drawing had got the device drawn the wrong way round. I later discovered that this little tester seems unable to tell the source from the drain. Swapping the S and D leads round makes no difference to the result of the test. I've never used the gadget for semiconductors before so I'd be interested if any of you have seen similar behaviour.

So, some progress is being made but still some way to go.

Cheers, John