开云体育

Hi Chuck,
Can I make a recommendation for your Manhattan Construction Classes?
Can you make a video about matching diodes?

Thanks!
Alan, N8WQ

I'm about to post my second video in an hour.? In it there is a
cheap Chinese component tester.? Find them on amazon and all your
favorite critter suppliers online.? Attached photo.? I have one
with the plastic case to prevent a disaster on a workbench with
a copious supply of clipped component leads.? :-)

Went over to the other desk, took the critter and I have a pill
bottle with a long strip of diodes and took four of them and
measured them.? Surprise.? The voltage drop was 253mV.? Looked
with jewelers loupe and the band is green.? They are Ge diodes.
I thought they were 1N4148s.? Need to label the bottle.

The voltage drop measurements show 3 decimal places and I can
see a +-1 mV change.? Not sure that is enough, but it may be.
I'll do a finer measurement in a video, but in the meantime
maybe someone else can do a finer report for the audience.

It'd starting point for testing.? I'd use a solderless
protoboard and a battery, a current limiting resistor
and power up diodes and measure the voltage drop at a low
current level, since that is where they are going to be
used in a ring diode mixer.

chuck, aa7fo