What is this?

[TechnoDave]

A few weeks ago, at work, I was moving equipment from one place to the other, and I came across this thingy. I was attached to a computer cable.
Its a BNC connector type thing with a 1/2 stub on the top of it with a green sticker that says "50 ohms, +/- 1% 0.5w"

Any clues?

Dave

 

[n5usr]

Sounds like a terminating resistor for old coax-based network cards. I used a bunch of them for Arcnet networks a few years back (the HVAC industry is slow to let old stuff die out!) but they were 93 ohms. Can't remember which color those caps / stickers were. The ones we got just had 93 stamped in the metal end, but there were some that used a variety of colors to indicate different resistances.

I guess it would make a nice dummy load for a micro-HT... (Not that their antennas are much better than that anyway! ;-)

 

[bezking]

It's a coax line. We used to have those in my office. It's a BNC connector, and 50 ohms. A whole wiring system would make for a hell of a dummy load!

 

[n8emr]

Most likely its a 10base2 eithernet cable. The cables are 52ohm and usually rg58 with BNC's on them. A terminator was required at the end of a run to make the system work correctly.

 

[TechnoDave]

OK, like I said in my other post. I really know nothing about antennas, or dummy loads for that matter. What did this thing do? What is a dummy load?

(I can only learn if you teach me)

 

[bezking]

In simple, this was pretty much an old network cable. You know CAT5E, which looks like a phone wire but bigger? This predated it.

DUMMY LOAD:: http://en.wikipedia.org/wiki/Dummy_load

 

[n5usr]

The coax network gear I am used to had a BNC tee. The coax cable attached to one side of the tee, and the terminating resistor was something like a BNC cable connector but with no cable (the resistor was inside the shell). It connected to the other side of the tee at the last computer on the link. The tee then connected to the BNC jack on the network card in the computer.

On old coax networks, the computers were all tied together in a daisy-chain configuration ("bus topology") one after the other. There would be a terminating resistor on the last computer at either end so the cable would work properly. These were some fun networks. You get someone who kicks the cable loose under their desk, and everyone on that bus lost their network access!

What I meant by my dummy load quip was you could pull the terminating resistor piece off the BNC tee (assuming that's how it is actually made) and use it as a *very*low* wattage dummy load. Not actually all that useful...