EEVblog > EEVblog Specific

EEVblog 1586 - Stranger Things Decade Resistor Box

(1/6) > >>

EEVblog:
A $12 6 decade resistor box, is it any good?
https://s.click.aliexpress.com/e/_Ddfe4PL
https://s.click.aliexpress.com/e/_DnK2irb

Kleinstein:
The switches may not last very long, but for less frequent use it may be OK. In principle the switch design looks good.

It is a bit strange they actually used 5 ohm / 50 ohm and so on resistors and not 2 x 10 ohm, 2 x 100 ohm and so on in parallel. This would have reduced the number of different resistors and given the 5 resistors at least a little more power handling capability. The 5 ohm is also actually 4.99 - so starting with a small error already, though likely less than the nominal tolerances.

At least it looks repairable, if one burns a resistor.

The .1 ohm are indeed of limited use, though not totally useless. It would be resonable easy to just change that decade to 1 M steps.

EEVblog:

--- Quote from: Kleinstein on December 14, 2023, 10:26:31 pm ---The switches may not last very long, but for less frequent use it may be OK. In principle the switch design looks good.

--- End quote ---

Most decade boxes only get occasional use.

[/quote]The .1 ohm are indeed of limited use, though not totally useless. It would be resonable easy to just change that decade to 1 M steps.[/quote]
Yes, I think I'll mod mine to 100k steps.

Macbeth:
I wouldn't be so sure. I have a 1970's ESI Dekavider that was clearly used by the Military Industrial Complex contractors by the calibration stickers and also a label stating that it should always be set to a particular setting for its job. Essentially a very expensive potentiometer in its day.
The switches are fantastic, double sided wipers, solid brass on gold plated contacts. The resistors are all wire wound and can cope with much power and high voltage.
This Chinese box looks just like a traditional Bakelite resistor box which would be of similar construction but is totally fake.
I have built a few tiny resistor boxes using digital decade switches and a 3D printer for the case. They are great but 0.1 ohm is ludicrous. Also I used 1W resistors on the 1 ohm range just in case. Lots of examples on EEVBlog forums.
Having said that for people who still deal with ancient valves/tubes then this is a great box to stuff some high wattage resistors in. The useless binding posts have to be replaced.

PartialDischarge:
I had one of these bought some time ago, and to make it short: To anyone owning this decade box, put it in the trash, it’s the best advice I can give.

Navigation

[0] Message Index

[#] Next page