Random teardown from the lab, a Sennheiser EW100 true diversity wireless microphone receiver.
Plus an explanation of how antenna diversity works.
the cartoon made me immediately think of the IT crowd. its 1/6th of an inch of stubble away from being Roy
makes me wanna play with nickel silver sheet
Inductor, inductor, inductor, inductor
It seems that ADKOM only designed the display board?
ADKOM is like 15km from here
Two mixers just means it's a superheterodyne receiver.
These days the IF (2nd) mixer might even be implemented in DSP, rather than having a physical mixer. Although, that might be overkill for a wireless mic receiver.
Nice video! It seems to have overlooked one small but nice hardware feature of the EW100 G3: just left of the display, there is an infrared (IR) interface. Why? Quite clever: the wireless microphones / belt pack transmitters have such an interface as well. When held less than 10cm apart, the user can synchronise the programmed frequency and the user programmable mic name (“Vocals Peter”). Quite handy! Setting frequencies on these small microphone transmitters is not trivial, especially when you have multiple mikes and are working under pressure such as in live sound. The presence of this IR interface makes you wonder how 'standard' the display assembly is...
Talking multiple mics, some have already commented on the fact that the EW100 supports DC powering related to its two antenna inputs. Actually, if you look well at the labelling on the back panel in the video, you can already see it’s DC power into the device (from antenna to device), and not from device to (active) antenna.
Why does this feature make sense? Audio engineers often use multiple wireless mics/bodypacks, so also have multiple receiver units. Also, they often have their receivers at the back of the venue (‘Front of House’), with the microphones on stage, and then want to use well placed, directional antennas. For such users, Sennheiser was selling ASA 1 Antenna Splitter alongside the EW100 G3 series (now replaced by the ASA 214 which supports G3 and G4 units). It not only allows you to connect a set of good active or passive antennas to up to four receivers (or 8 using two splitters), but, using the DC powering feature, also power all these receivers. This not only makes the setup cleaners, but also more reliable. (Not irrelevant, I had a EW100 PSU failing myself, too bad that these expensive devices seem to come with not-so-good quality power adapters…)
Kind of in the opposite direction, for in-ear monitoring (IEM), Sennheiser has a similar system on the market: with an AC 41 antenna combiner, up to four (1/2) rack-mount *transmitters* can share a single antenna while the combiner also powers all these transmitters.