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?

In article . com,
wrote:

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

Is my chip dead, or is 40 meters dead?

Can't say anything about the health of your chip.

There are times when 40 meters is dead, or pretty weak. There are
other days when it's fine. Sunspot numbers have been quite low
lately. The Western States Noontime Net on 40 meters was fairly weak
today and was weak yesterday... the net controls commented that
propagation was horrible. For a couple of days before that,
propagation was excellent and signals were just booming in.

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 don't ever hear much in the old 40-Novice band segment. There's
enough foreign-broadcast interference after dark these days to drive
most ham activity out of the 7100-7300 frequencies. There's usually
some CW pipping away down at the very low end of 40 almost any time I
tune around to check.

The phone segment on 40 is usually quite active during the day, if the
band conditions aren't too horrible, since most of the foreign
broadcast interference is heavily attenuated.

My impression is that 15 is as dead as a doornail after sunset these
days.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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