I'm having exactly the same issue.
I recently got 2x BP-TRX units (timecode kit), 1x HD-TX and 1x DUO-RX for various uses (mainly corporate video stuff where I need to chuck a mic on someone quickly or get TC/waveform sync with very little time to set up). Love the idea, but I'm getting horrific RFI noise on both the BP-TRX units to the point of them being unusable for my purposes.
I've tried pretty much everything. Unpairing/re-pairing, isolating each unit by powering off, firmware update on everything, changing every setting including RF power/latency, turning TC off, trying every possible tx/rx configuration between units, system reset. No luck.
I'm not in a place with unreasonable 2.4ghz interference, just a normal house with a standard wifi router and a couple of mobile phones nearby. I even tried unplugging my router and turning off every other device nearby running on 2.4ghz.
Feeling pretty stuck and considering returning them.
Observations:
noise type is an intermittent mid/high frequency stuttering very typical of digital RF interference you'd hear on a cheap mobile phone or similar. It's incessant but often disappears momentarily depending on how the units are positioned, but it's there most of the time.
loud enough that audio is functionally unusable (-20db to -10db under typical dialogue, registers on the VU meter clearly)
clearly audible through the transmitters headphone output as well as the receiving unit
carries across to the transmitters onboard microsd recordings, identical to the headphone output and receiver
noise stops when transmitter is unpaired from the receiving unit or the receiver is powered off
same issue on both BP-TRX units when transmitting, regardless of whether it was being received by DUO-RX or another BP-TRX
RFI noise volume increases with input/preamp gain
noise volume reduces when included mic (W.Lav) is unplugged, but still audible
noise volume reduces when another mic (sennheiser ME2ii) is used instead of the included W.Lav
noise is not present when using the REC ONLY mode
the same issue is not present when transmitting from the HD-TX with the W.Lav to any units (DUO-RX or BP-TRX), indicating it's a problem with the transmitter mode on both BP-TRX units
I've messaged Deity support but haven't heard back yet.
Is this a known issue that someone like @Andrew From Deity could shed some light on? If so, is there a way of resolving this or have we just got faulty units that need to be RMA'd?
I'm really determined to make these work if possible.