Re: Yet another use for a curve tracer


I don't have a BK 501 but I do have a B&K 540 "Component tester". It's a
small AC powered unit with about a 2 1/2" CRT. The whole thing is about 7
inches wide and about 2 1/2" tall and about 10" deep. IIRC it has two
current ranges and two voltage ranges and it's strictly an I-V tester so
it's not nearly as accurate as the Tektronix curve tracers but it is a
*very* *handy* device to keep on the bench for quick testing of
semiconductors and for identifying passive devices. IIRC it's the same or
very similar to the Polar T1200 component tester.

I have the manual for a B&K 501A and it looks like a decent unit but it
doesn't the capabilities of a Tektronix Curve Tracer but it will display
multiple current steps. It would also be easy to add a variac to it to get
the continuously variable collector voltage capability.

I also have a Hicock unit similar to the B&K 501 but it also has the
capability of testing vacuum tubes. I'm looking for a manual or even just
the specs for it if anyone has them.

On Fri, Dec 4, 2020 at 10:19 PM Daveolla <> wrote:

Does it not need a minimum load. I just hook them up to the AC cord
and a light bulb. I guess I'm stupid for keeping it simple (KISS)

There were opinions earlier on other brand Curve Tracers, EICO
and Heath, any opinions from the group on the BK 501A Curve Tracer?


At 08:18 PM 12/04/2020, you wrote:
I've been cleaning up and organizing lots of stuff lately, and I
found I had a couple dozen various AC light dimmers and fan controls
piled up. After I eliminated the obvious junkers - marked bad, taken
apart, busted parts, etc - I had about a dozen left, to save for
possible re-use. I decided to check them out on the curve tracer, to
eliminate any more bad ones from stock.

I set up the 576 for AC, 350 V peak range, series R 680 ohms, H 50
V/div, V 100 mA/div, and started testing. It worked great, and all
of the two-terminal types checked OK. There are some three- and
four-terminal ones that need further study to figure out appropriate
hookup. Here's the process, for two-terminal types:

1. Set collector supply to zero.
2. Hook up dimmer.
3 Set collector to about 175 V peak.
4. Run dimmer knob through OFF and full range.
5. Display appearance should change according to dimmer setting,
from a flat line or small "+" to a large "+," indicating proper operation.
6. Turn collector back to zero.
7. Disconnect dimmer, and connect the next one.
Repeat as needed.


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