Topic: TSKB 75 ohm for mic cable?

[kirk97132]

A quick search didn't reveal anything one way or the other.  So Any issues using a cable rated at 75 ohm for mic cable?  And if it is double shielded are there any RFI issues as opposed to a twisted pair?  IE: is is more likely to get RFI over a twisted pair (or quad core), or would the double shielding take care of that? TIA, Kirk

[notlance]

What is "TSKB 75 ohm" cable?  I assume it has 2 conductors + shield?

The twisting is important for balanced lines, like mic cable.  The twisting is an attempt to have the two conductors occupy the same physical location so any induced noise will be equal in both conductors.  Quad core takes this one step further such that by pairing each conductor and twisting the four together, the "virtual" location of the balanced line can be placed on top of each other.  Quad core can have up to a 20 dB greater Common Mode Reduction Ratio (CMRR) vs regular balanced lines.  Common mode reduction is more effective at lower frequencies, such as the noise induced by power lines, rather than noise induced by higher frequency RFI.

[yug du nord]

What is "TSKB"

Tapers Section Knowledge Base

[notlance]

So if you are referring to 75 ohm coax cable, that would make awful mic cable.  It is unbalance, and its handling characteristics are terrible.

[kirk97132]

Thanks guys.  There is actually a chance to buy some really nice solid silver cable which is rated at 75 ohms.  It is all stranded so I am not concerned about handling characteristics.  And it is actually two separate cables, each a cable with a shield, which are then enclosed by another shield so it can be wired as balanced.    I knew that 110 ohm was fine for audio so it looks like the 75 ohm resistance is ok too.  The balanced signal and the shielding being more relevant to sound quality than the resistance rating

[ScoobieKW]

Thanks guys.  There is actually a chance to buy some really nice solid silver cable which is rated at 75 ohms.  It is all stranded so I am not concerned about handling characteristics.  And it is actually two separate cables, each a cable with a shield, which are then enclosed by another shield so it can be wired as balanced.    I knew that 110 ohm was fine for audio so it looks like the 75 ohm resistance is ok too.  The balanced signal and the shielding being more relevant to sound quality than the resistance rating

Remember it's a twisted pair that is key for balanced, not just 2 conductors and a shield. Unless you are running 2 wire mics, or building adaptors to go from 1/4" Tip/Sleeve to XLR, this is the wrong cable for the job.  I like 75 ohm coax cable for RCA cables, and used it in my car audio install, but for balanced? No.

The wrong product at the right price is still wrong.

[kirk97132]

Thanks everyone