Nothing fancy inside, home built but good solid construction. Inductors are about 1.5cm diameter with thick copper wire (no silver I'm afraid).

Peter,

Great to hear we were all on the right track. Is it silver plated or anything internally? Pity it is only low-pass, a VHF bandpass might make a nice 1st IF filter for a HF spectrum analyser.

I've been thinking about building one around 150 MHz where it is relatively easily to build a LO that can be pulled over 30 MHz or more with reasonable linearity. Then a 2nd LO to mix that down to 10 MHz where a crystal filter would provide the resolution bandwidth, followed by an AD8307 for the log detector.

Still writing up the other adventures of last Sunday... So much to document, I may not get anything else done this weekend.

Regards,

Alan

Great Photos!

The mystery box turned out to be a low pass filter, my guess is for 2m (but I haven't measured it).

Very nice construction internally with three internal chambers.