Tac!T should be relatively immune to RFI.   It uses a true balanced amplifier and capacitive/inductive filters to minimise any RF entering and exiting the unit; however, it is an active device, and in extreme RF fields (e.g. an area with several active mobile phones) it may be impossible to prevent some interference.   Sensitivity to RFI is strongly connected with both the microphone and the pre-amplifier it connects to, and you might find that using a different preamp or mic resolves any issues entirely.  

With the Tac!t cable, current draw is necessary for the circuit to operate: the device will not work with dynamic microphones that do not pull current. The actual current draw varies with the load used, so it's not possible to provide a specification for it. The circuit demands are very low, and with IEC 26815 compliant P48 supplies it is very unlikely to cause any problems. With excessively hungry microphones (e.g. those that suggest they need the full 10mA available, such as Earthworks), or phantom powering that cannot deliver adequate current (or is significantly under-voltage), you might start to encounter a few problems. The likely outcomes in such cases are under-performance of the microphone in terms of max SPL etc., or a slight increase in self-noise. Tac!T can stack with internal mixer filters to create a dual slope HPF, but perhaps has its greatest value in applications such as camera inputs where no HPF option is provided.  

The Rycote Tac!T (pronounced 'Tass-It') cable is an in-line, active, third-order (18dB/octave) filter with a knee at approximately 60Hz. It has been meticulously designed to pass desired audio unaffected, whilst massively reducing wind/handling noise and other LF vibrations encountered on location. The Tac!T filter draws its power from P48 (48V phantom), whilst also passing power simultaneously to the microphone. It is electronically symmetrical and does not disturb the intrinsic balance of the microphone circuit; nor does it introduce any signal loss for normal programme frequencies. Tac!T has been adapted to fit entirely within the body of a Neutrik XX-series XLR connector. It is non-switchable, and the electronically buffered circuitry ensures that its performance is consistent for almost all industry standard phantom-powered microphones and preamps. Front-end filters on mixers are usually 6 or 12dB/octave, and result in a greater loss of wanted higher frequencies for a given cut of infrasonic or extreme LF noise. A steeper third-order filter (18dB/oct) like the Tac!t is much more effective for production work. Compatibility Notes: Tac!t is compatible with any P48 (phantom) powered microphone using a 3-pin XLR connector. It must be connected in the signal path between mic and mixer/recorder, and is ideal in situations where the user’s device has no built-in HPF.

Note that Tac!t is not compatible with un-powered dynamic or ribbon microphones, or T12 and P12 powered models.
 

Noises like this are extremely rare, but can occasionally result from an enlarged joint or joints. (The Duo-Lyre® system uses specially designed dovetail joints to secure the microphone grip snugly, since adhesive can cause creaking sounds if applied to a moving section.) By securing the mount with one hand and holding the Lyres steady, the microphone grip can be moved around to establish whether a loose joint is indeed the source of the noise. We will happily have a listen to the unit here at Rycote HQ to confirm the fault, and will issue a replacement if necessary. If you are encountering this issue, please get in touch with a Rycote technical specialist in the first instance by submitting a support ticket. Additional information on the InVision 7HG MKIII can be found in the following video: