Each month features an updated reprise of a Tech Tip from ten years ago because many past Tips are well worth review. Also, some will benefit from updating. Enjoy the thirty-seventh monthly Tech Tip reprise.
It is common knowledge that an audio signal can be “too strong” and cause distortion when connected to an input that cannot handle the excess signal. One example would be a line level signal connected to a mic level input – the result is distorted audio. An attenuator, or “pad,” can be used to reduce the level of an audio signal to eliminate the distortion.
It is not as widely known that RF [Radio Frequency] signals can also be too strong and cause poor performance when connected to a wireless receiver or to an RF distribution amplifier.
Certain Shure antennas, like the UA874US or UA864US, have a user selectable circuit that will attenuate the RF signal strength as it leaves the antenna. But what if the RF signal needs to be reduced and there is no attenuation switch on the antenna? Then an external RF signal attenuator/pad is required. It is installed before the RF input on the wireless receiver or distribution amplifier.
RF Industries, San Diego, California, offers numerous fixed RF pads, also available is a device with selectable attenuation levels: the model RFA-4056-03; RFA = Radio Frequency Attenuator. This versatile attenuator, with BNC connectors, is adjustable in 1 dB steps up to a maximum of 30 dB. The RFA-4046-03 can be employed to determine the precise value of RF attenuation required, then be replaced by a fixed pad of the same value.
RFA-4056-03 RF attenuator
Related information: http://www.rfindustries.com
https://service.shure.com/s/article/adjustable-rf-attenuator?language=en_US
Arcana – mysterious or specialized knowledge
In the Shure product line, the model A15AS is an attenuator/pad for audio signals. Its function is to reduce the level of a signal by 15 dB, 20 dB, or 25 dB. The “AS” in the model number signifies Attenuator Selectable. The previous version of this model was the A15A – a fixed pad of 15 dB.
A15AS signal attenuator
***
Shure was front and center at the Summer Olympics opening ceremony in Paris – viewed by tens of millions worldwide. Colleagues, such televised free publicity is the pipe dream of our worthy competitors.
Celine Dion with a wireless Beta 58
French metal band Gojira with a wired SM58
