Hello Dave.
So far I have identified 3 different Leeds & Northrup "Boxes".
Originally my intention was to re-purpose the box, panel connectors and
switch for a project to make my own precision resistor banks.
All use different switches and vastly different resistors to achieve
their original
No environmental chamber yet, have a Yokogawa controller and and an EIS
sensor simulator, going with a small box in the first for individual
components, but workload keeping me from completion of so many fun
projects. Now we are nearing grass cutting season here, the completion
of projects ratio
Maybe if you temporarily repair he connections to the broken transistor,
the working status can be verified and readings taken, perhaps even mark
those pot's positions, and when its working, twiddle them back and forth
around that marked position while noting any changes in out put etc If
it is
Thank you I will open it. I was not trying to give advice,
rules-of-thumb are simply shop guidelines we use to deal with our
inadequate equipment (which are may when it comes to high precision).
George Dowell
On 2018/05/02 09:36 AM, Dr. David Kirkby wrote:
> On 2 May 2018 at 14:25,
Well, that "fixed" my instrument. There was no battery inside. Rather
the "battery test" was reading the charge on the main power supply
capacitor. It must be of high quality because it keeps a charge for a
considerable time.
Everything works just fine ad tracks precisely with my bench
First class work there Mitch.
Did I see a ham radio?
73 DE K0FF
George Dowell
On 2018/04/30 09:19 PM, Mitch Van Ochten wrote:
> Built a small temperature chamber using a Starbucks Refrigerator, Yokogawa
> Temperature controller, and PTC Heater (300 watt). It covers 0 degrees C to
> 55
Good strategy Nigel.
Wet slug tantalum- yuk.
I've opened sealed packaging around new but in extended storage Canberra
NIM 5kV power supplies, had he unit smoke first time hooked power to it.
The rest of them, I just went through and removed all the tantalum
bypass caps before first test
Fractional and even Ohm resistors-
Once, in a package from Russia, with some items totally not related to
this group discussion, the seller included 2 boxes of 1/2% 200 ohm
resistors with a note of thanks for the purchase. Each box contained
several cardboard carriers with 25 resistors lined up
With a temp. rating 0-50 C, 1ppm/C
22V input from regulated bench supply to an IET High Stability Voltage
Reference module, or HSVR-6.3, specified at 6.2998V (ref. NIST). At
first power-on it read 6.25V then started settling down.
Measurements made with in-factory-calibration Keysight
