I'm building the MB Upperdecker for friend. I read somewhere it was recommended to use shielded cable. Do I need to connect the outer shielding to ground for this be effective? Or, does the metal shielding around the wire itself protect from interference? I'm supposing it needs to be grounded but hoping it doesn't;)
Also, should I run shielded from input jack to 3pdt, 3pdt to board in, board out to 3pdt, 3pdt to output jack? Is this overkill? Then there is the boost section that runs to it's own 3pdt. Seems a real PITA to run shielded cable and ground it at every point where the signal travels! Talk some sense into me:)
Speaking in general terms, as I've never built the circuit you mention...
I've never actually needed to shield anything as the enclosure obviously did enough shielding but if I were to need it, I'd
- shield input jack to 3pdt
- shield 3pdt to board
This is the signal that gets amplified the most (coming into the circuit) and any interference is going to be inserted into the circuit.
From what I understand, you only need to ground one end of the cable. I'd probably ground sides that end at the 3pdt.
Now, let's wait for someone who's actually done that! ::)
Recommendation.....
Use the shielded cable (I recommend RG-174) and run it from Input jack to 3PDT and 3PDT to Output jack.
Also, it would be wise to ground the outer shield somehow. WARNING: ONLY GROUND ONE END OF THE SHIELDING. IF YOU GROUND BOTH ENDS, YOU JUST CREATED A HUGE ANTENNA!
Just ground the shielding on each jack to their respective Sleeves ;)
If you are still getting noise, then you can go from 3PDT In/Out to the PCBs but, I doubt this will be the case.
Good Luck! ;D
Great guys. Thanks for the quick response. I played it on my testing rig (always noisier) and there was quite a bit of noise. Want to do it right the first time. Thanks for your help!
GL, I bought the shielded cable from SmallBear, don't remember what it was called.