Need suggestions for a control board to use in a high A M RF enviroement

[rew]

Can anyone suggest a good board to use at an AM station. Something that is immune to RF interference. I know grounding ect. is important. RF has always been bad at this station.

 

[TPO]

Just as important as the board is the way it is installed. I see many boards with good RF immunity made to act like antennas due to poor wiring. When it comes to wiring the board I'd be glad to offer some suggestions to keep the RF at bay.


Pacific and Autogram used to make boards that were practically bullet proof as far as RF was concerned. You'll want something with an all-metal cabinet. Balanced inputs and outputs are a must. What price range?

 

[al_atl]

I've got a Gates/Harris Stereo-80 available. ;D Working when removed from my basement studio last summer.

 

[rew]

Just as important as the board is the way it is installed. I see many boards with good RF immunity made to act like antennas due to poor wiring. When it comes to wiring the board I'd be glad to offer some suggestions to keep the RF at bay.


I would like to hear your suggestions on the wiring. Ihave been in this line of work for almost 30 years and fighting RF at this station for almost that long. I think I have tried almost everything. Maybe some new ideas is what I need. Never to old to learn new tricks.
The old Gatesway 80 is still working so I am in the "Begging Phase" at this time. Just tring to get it in the budget.

 

[OKCRadioGuy]

Try an old PR&E BMX II, preferably one with transformer inputs. Try www.MooreTronix.com if you can't find it elsewhere cheaper. Run ALL your power though filtered power strips (believe it or not, Radio Shaft still has several with 40-50 or so db of broadband noise filtering!). Ground the console and racks back to your station ground with copper strap. It would pay to have the entire studio screened on all 6 sides and tied back to the station ground, but you probably don't have the money to do that part. Use balanced audio. Sometimes you'll find grounding one end or the other, or sometimes BOTH will make an input behave. Many times you're just going to have to hang a .01uf cap across the input plus to ground and one across the negitive and ground, preferably close to the console itself. Torroids are cool, but in general I haven't had all that much luck using them. Telephone lines make wonderful antennas, so consider good telco filters like the ones produced from Suttle. Try Graybar electric. For the blowtorch I lived under for over five years, the model number was Suttle 1542A. They are block-frequency dependant, so you'll want to get the right one for your station. They might have to order the right one for you. One thing to do when you get a console is make sure and filter the power first, then hook up the output. Then, turn on all the channels while observing if you're hearing RF noise. If all is good, start hooking crap up. If you start hearing the RF, you'll know where to start working to beat the beast down. The best thing and the most important thing is make sure EVERYTHING you have connected to that darn console is run though the power filter and grounded to the station ground. At the place I had to deal with 50k night-time directional right over the studio complex (can you say 160k ERP blasting right at you from your backyard!?), we had the entire room running though TWO power strips chained together. Be persistant. RF issues can be hell, but you can win against the beast.

Good luck!

 

[thebeaver32]

LPB boards are fairly AM RF-proof. Worked with a number of them over the years. They are pretty rugged, too.