Topics

Shielding volume / mic / tuner cables


Kit Peters
 

As part of this build I'm doing, I'm moving the 4 pin mic, the volume, and the tuner knobs a few inches from the main board. Should I try and shield these cables at all, or is that not necessary?


Ted
 

A lot of pre-build testing involves two dangling wires and an eletret element hanging in air with no problems though it's easy to take some precautions for the long haul.  I'd wrap the mic hi wire inside an earth/ground wire, in twisted-pair style for much over 2-3 inches.   For the volume knob, it does no harm to do the same for the audio going and coming though some may see it as overkill.  It does no harm to go the extra few seconds with it.





-Ted


Evan Hand
 

On Sun, Oct 4, 2020 at 10:16 PM, Kit Peters wrote:
Should I try and shield these cables at all, or is that not necessary?
Kit,

As Ted stated, it does not hurt.  As to being needed, most of the build pictures that I have seen online do not.  I have not used shielded cables in the three kits that I have built (not including two moves from ugly self-made cases to the AmateurRadioKits cases).  The case kits from AmatuerRadioKits.in do not.  In fact, those cases moved the controls through another board with jumpers from the stock boards.  I would suggest you go look at some of the pictures of the case builds there. The pictures are a little hard to find.  They are in the download section of the site.
https://amateurradiokits.in/downloads/
The uBITX Nextion Case 7zip file at the very bottom of the page has the pictures.

73
Evan
AC9TU


Curt
 

when using voice or CW, the signals at the front panel tend not to create any issues, or be susceptible except for picking up lots of stray RF from the back side end or the external antenna.  many examples of folk building their ubitx into plastic boxes without issues - so I think it is mostly keeping the RF in coax when it leaves the board - and also not having the antenna too close to the rig - or operating into a poor mismatch - yes hard to be exactly numeric.  I suggest see if simple works before getting too complex with wiring.  if you did experience anything, the audio wiring would be the first thing I would examine.  those with severe RF leakage can reset the raduino each transmission.  explore and see what works for your situation.  operating data modes might put more stress on audio shielding, but in theory it shouldn't. 

73 curt