We (Wayland Radio) are now at a stage where it would be useful to inject IRN/SKY news into our automated overnight/unattended TX. However, and there's always a however, I'm finding it really difficult to find an 'off-the-shelf' audio switcher to take a simple control command from the PCI1750 card to inject the audio into our TX chain.



This might be because I'm being picky... We use a Sonifiex RB-OA3 studio switcher, it works very well for us but it has a unique feature that allows an external source to be directly injected into a '9 pin D-Type' on the rear of the unit and this is where the 'however' comes in, again. For this input to work correctly and maintain optimum performance it requires a couple of contacts on the socket to be shorted when the socket is not in used to inject audio, so as not to reduce the units performance by 3db.



I'm after a switch (relay/solid state) that when activated removes the 'short' and feeds audio to this socket then 'shorts' the pins to maintain quality when no audio is present. This is not just a case of shorting the audio inputs, but shorting between on leg of the audio and, I believe, the ground on the switcher.



I did ask Sonifex at the last SBES (2008) if they intended to make a box to do this operation and they don't (currently) but would investigate the possibility, in fact I think I might have been the first person to ask about this as an option.



Any suggestions from the team here...



I'm not looking for a complex solution but a simple 19" rack mount box option with pair of XLR3 inputs and '9 pin D-Type' output and '25 pin D-tpye' control plug for the PCI1750 to connect to and an internal power supply with IEC power input.



This unit would then sit in the rack, connected to our Myriad automation PCs control card, IRN/SKY News would be feed to the unit from a dedicate pair of balanced inputs for the News DA all interconnected to the Sonifex Switch via the 'D-Tpye'.



I look forward to the comments.



Roger.

Roger Woods
Producer/Presenter/Engineer

Hello, here at HRB we use a Sonifex RB-SS10



http://www.sonifex.co.uk/redbox/rbss10_ld.shtml



I use it in mix mode, so it mixes Sky news onto the studio feed.



Works very well!

Don't forget the P Squared IRN Audio Switcher, connect in a balanced or unbalanced audio feed into the 15way D type, along with the control closure from the PCI1750, and the Output, and bob is your uncle!

It's not rack mounted, it doesn't have XLR ins and outs, but it is £100.00 +VAT & DEL

Contact sales@psquared for more info

DB

Regards

David Boulton
Brand Manager
Broadcast Radio Ltd

Hi Roger,



Don't know if you've found a solution yet, but I've worked out that the bits to make a unit in a rack mount box would come to just over £80.

Its Alive! Its Alive!

I guess the orginal poster by now may well have sorted out a solution to their problem - but as a few comments:









Obviously you only wish to switch one feed - but the sonifex red box which Simon suggested will work nicely with the PCI1750 card - and gives you ten switchable feeds. I've got just such a set-up at one station - we've yet to find 10 different feeds we want to switch, but did have at least 4 feeds on a regular basis, with level adjustment needed on each input, plus potentially other inputs, so worked out cheaper than multiple PSquared 'black boxes'.



I take the output of the Sonifex source selector into the line input of the Mia card in our automation PC - where it gets mixed in the sound card with the Myriad output to give me a combined 'automation' feed which becomes the 'studio 3' input on the Sonifex RB-OA3 studio switcher. (Note - make sure you run the source selector in 'mix' mode otherwise the last hardware line selected takes precedence and what Myriad thinks is switched on is not necessarily what actually is!)



I have avoided the external source input on the Studio Switcher for one simple reason - if one of the real studios are broadcasting - the Myriad automation PC may still be playing it's log (possibly even in 'preview' mode where time markers might not be hit) I wouldn't want extra audio getting injected into the broadcast chain outside of the control of the operator in the 'on-air' studio.







Going back to your situation, if you want to use the external input, I can't recall if the PSquared black box is stereo or mono, but assuming it is, basically it is just a couple of relays and associated electronics, assuming the box has a couple of DPDT type relays - if you weren't frightened to do your own mod you could switch one of the relays connection to the Normally Closed terminal rather than Normally Open where you could switch the news through one relay and the reverse logic for the 'mute' function on the studio switcher input.





If you are going to go down the 'build it' yourself front - take a look at Paul Blitz's page:



http://www.blitzfamily.eclipse.co.uk/paulblitz.co.uk/tech_tips/techtip/art_ind.htm





Incidentally the socket on the PCI1750 card is a 37 pin D-Type (not 25 as you state) and Maplin electronics no longer sell 37-way DTypes ("no one was buying them" they said) most annoying when you want one in a hurry!


--
Myriad user since 1998, now custodian of dozens of Myriad,Autotrack, Powerlog and Scoop boxes of many different flavours.
http://www.philedmonds.com

Paul Blitz's website has the instructions and diagrams to build a box to do what you need - works well for us.  www.blitzfamily.org.uk