SJAC 106.7 LPFM Low Power Community Radio
Audio and Transmitter Details .
The audio for the music and community announcements is provided via a 2 channel mixer from a laptop computer via another computer running Stereo Tools audio processing software back to a switch unit which allows us to switch between the music programme to the church live and also an ALL OFF emergency switch.
The computer is run by DirEttore broadcast 3.1 Radio Automation Software ( www.mixtime.com )
The audio for transmitting the live church services and announcements is provided from the main church PA via the tape out terminals to the 2 channel station mixer and the 4 channel Audio sound mixer..
Most of the church audio inputs Lecturn mics, radio mics, are run through a multi channel mixer to the main PA. The exception is a Choir Mic dedicated to picking up the sound from Auditorium and the congregation. the other audio inputs, tape deck cd player laptop audio inputs and one mic are run to a submixer which connects to the main PA via aux input. The main output of this is fed to a stand alone PA which is for audio only into the auditorium.The main mixer connects to the Main PA via a 32 channel equaliser. This separation is required for the control of the live broadcast. We can have up to nine open mics during a full service, so feedback control is critical. The Rogers organ has its own PA and speaker system. It gets complicated but it works The sound guy has to be on his toes at times but the system works well even with no operator if required such as at an evening service.
The Transmitter is an NRG 1 to 4 watt transmitter with built in pre-emphasis. ( running at the 1 watt setting due to local regulation) Into this the audio is fed via the dedicated radio mixers to a computer running Stereo Tools then to a limiter/compressor unit. This gives a very good and clean signal to the transmitter. The modulation level is controlled to max 4.5 on the deviation meter (if you know what that is ) but they tell me that that is good.
No splatter on the signal.
Radio automation software.
The software here is DirEttore from Mixtime. www.mixtime.com. Over the years we have used Direttore from Demo to version 1 to now 3.1. ( and have yet to be disatisfied.)
Depending on the version used is the level of control enabled.
We are using the Pro Broadcast 3.1 version which provides an excellent level of control over the final programme. And has run automatically for years with out problems.
It is too technical to describe here suufice to say that it gives good and reasonably smooth transitions from music tracks to sweepers and programmed events. Check out the Mixtime site.
There is also software EQ and compression options along with output level meters which is helpful to check the level inputs into the transmitter hardware compressor. Although whether or not you need to run both is problematical I do use a small amout of software compression as well as the hardware, and the EQ just trims up the audio frequencies from the computer nicely.
Our New Layout for Radio Station and sound desk
(This has been upgraded yet again with additional mixers and equalisers. New pics to come later).
View from sound desk to front of Chrurch
Original church sound and transmitter desk layout
(Don't look behind the control cabinet. You will just know what the cable runs will look like.)