From time to time I'll put up here details of the current project underway. Click on the image to get a larger view, I'm still playing with the video capture so the image isn't the best ever (and the reds out of my old Saticon camera seem down)
Right now I'm rebuilding the 24GHz system. The rx is complete but not air tested and the tx is under bench test.
The system should deliver 100mW have a system noise figure of maybe 4dB.
Problems? Well, the TX mixer isn't delivering as much power as it used to and so that is currently the target of the work. Having looked at things more closely the PCB bonding to the plate has come away. This was silver epoxy. As the photo shows, very little has stuck to the Cu foil. The plate has already been cleaned up. So maybe I failed to degrease the PCB or didn't do a good job on the mix. Also, the number of through ground connections is down on my usual number so I'll improve those too.
The RX was air tested at the weekend (more than can be said for the 47GHz gear) and so all that is left is a sequencer and PSU for the 100mW PA. I'll put info on that up, especially the 24V relay cct soon.
More as it happens, as they say.
Jan 1998 Well it is finished and boxed, the PA doesn't perform as well on 24G as it does on 22.8G but I'll live with that unit until I get some new PA PHEMT's from Stanford Microdevices then I'll put the old PA into use on 47G. The relay design was published in the RSGB Microwave Newsletter in January and will be on the web page shortly. Back to the home page