The RF-OPT reference is NOT a physical item.
It is a line to be added on the PO to any item reference including a MONO cable (or a cable itself).
This option is only potentially useful when using DIGITAL transmitters.
Standard cables, without RF option, are already very well shielded:
- Braided or double-served shield (high overlapping). Internal pre-oiling to increase flexibility and eliminate any friction noise.
- Metallic caps for male and female XLRs (proprietary machining). Electrical continuity with ground.
The RF option is an ADDITIONAL internal filter (balanced choke), generally in the female XLR (as close as possible to the microphone). It is indicated by a RED marking, generally a heat-shrink tube.
The RF option can NOT be added to an existing standard cable. It is an intrinsic option of the cable, determined at the time of ordering.
A cable with an RF option is strongly protected against interference (hiss and various noises) generated by the use of digital transmitters…but perfect operation can never be guaranteed!
Faced with a digital transmitter, some microphones do NOT need this option (Schoeps CMC1, Neumann KM184/185 and others), while others will remain unusable even with oversized shielding (Schoeps CMC5, Neumann KM140/150 and others).
