QuantAsylum

[e30m3mon]

Would ferrite beads in the signal path help with any of that 60hz or are those typically reserved for higher frequencies ?

 

[Gepetto]

Would ferrite beads in the signal path help with any of that 60hz or are those typically reserved for higher frequencies ?

Much higher frequencies Al...

 

[George S.]

Looks like STP (Shielded Twisted Pair) cable is the cable of choice for differential use, no coax. Some are even using STP Ethernet or microphone cable. Very EMI resistant.

 

[Gepetto]

Looks like STP (Shielded Twisted Pair) cable is the cable of choice for differential use, no coax. Some are even using STP Ethernet or microphone cable. Very EMI resistant.

Unfortunately that does not BNC very well George

 

[J!m]

Star-Quad for balanced cables. Cardas or Mogami.

 

[George S.]

More reading required. Thanks guys!

 

[Gepetto]

Star-Quad for balanced cables. Cardas or Mogami.

That doesn't BNC very well either Jim. BNCs are designed for coax termination.

XLRs are designed for balance termination

 

[NavLinear]

If you want to test a balanced output you might look into an adapter.

 

[laatsch55]

Dennis, have you used much Neutrik stuff?

 

[NavLinear]

Dennis, have you used much Neutrik stuff?

i have some balanced cables from them. They work well and are reasonably priced. I have not used one of their adapters yet.

 

[laatsch55]

Thanks..

 

[George S.]

Here's a good explanation. Figure #2 is key.

 

[J!m]

That doesn't BNC very well either Jim. BNCs are designed for coax termination.

XLRs are designed for balance termination

I thought we were talking about balanced line?

 

[Gepetto]

I thought we were talking about balanced line?

Sort of, we are discussing the Quantasylum differential connections that use BNC connections, similar to many pieces of test equipment

 

[George S.]

One single ended to differential cable completed. Using Monoprice STP balanced cable I cut out of a patch cord. I sacrificed one cord by stripping it to look and ensure it's truly twisted and not parallel.
I separated the shield and twisted it around the leads at the break out for the BNC's. Was a PITA to do as no coax was used, and as Joe stated, BNC connectors are made for coax.
Another one of these to make, then a loop back with two BNC's on each end.

 

[WOPL Sniffer]

George, did you get your new 403??? Joe, did you get one too?????

 

[WOPL Sniffer]

George, did you get your new 403??? Joe, did you get one too?????

I haven't had much time to play with the 401 I got. QA sucks, he builds enough to keep in stock for an hour. He made everybody wait so he could sell the Programmable Loads at the same time. Now you can buy a programmable load, and there are not 403's or 404's available again (like the last 2 years) so screw him, I'll use the 401.

 

[George S.]

Yeah Sniff. Spent some free time today making differential cables for the QA403. No more 60 Hz spike. Actually, rather amazing how they work. They were a bitch to make, but worthwhile.
Now sitting at the monitor making loop back tests, trying to understand full scale input and attenuation.
I did post on the QA Forum asking questions about the cables. They weren't much help unfortunately.

 

[George S.]

60 Hz is much lower with the differential cables. This is with everything in the room on. A sound system, LED lights, Halogen light, big box fan running in the window, laptop plugged in on power. I have yet to experiment with the flat ground strap from the laptop to the QA case. Very happy with the new loop back cables. We'll see how the single ended to differential cables work out. May have a ground loop with them.
The 1024K FFT setting is the highest resolution. Pretty decent distortion and noise figures.

 

[Gepetto]

George, did you get your new 403??? Joe, did you get one too?????

Patiently awaiting the 404 Perry...I hear it has 8 fins.