xpyttl wrote:

The NE602 was an old part.

Speaking of the NE602 - the old one - I have a question...

Is my chip dead, or is 40 meters dead?

I recently got re-interested in RF and pulled out some old parts to
play with. I wired up an NE602 on a breadboard (yeah, I know), with a
torroid, some padding caps, and a varactor for tuning, and got is
oscillating on what my scope (yeah, I know) claimed was around 7 mhz.

Lots of domestic AM broadcast interference eventually tamed, but then
only shortware broadcast received at these frequencies (ie, tunes like
AM should with a direct conversion receiver) - no ham CW. I do
remember from way back when that I found the novice 40m band useless in
the evenings and would hang out on 15m then instead. Is that still
true right now?

I know the receiver isn't totally dead as I increased the capacitance,
tuned it down to what my scope claims is 80 meteres, and heard CW.
Added an old op-amp audio filter circuit from the handbook and it's
almost useable on 80m, but tuned back up to forty and nothing but
broadcast...

What kind of ballpark magintude of oscillation should I measure if I
probe the tank (well, actually pin 7) with a high impedance probe?