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Relocating FM Transmitter Question


Liberty-Laser

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I ran Cat5 cables from my basement to garage to run my show from my PC.  I had forgot about the FM transmitter -   I'm using a Ramsey 30B with antenna located in the attic above garage.

 

Question:  Which would be better and/or cheaper - Running 100' cable to the antenna or a 75' cable for the RCA audio connectors?

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I would (and did) run the longer cable with the audio. If you end up with noise (particularly hum) problem, ask me about it and I'll offer some suggestions.

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Extend the audio signal cables and do yourself a favor and order a ferrite filter to put on each end of the cables they're stupid cheap so why not go ahead and get them

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I ditto what has been said so far. Reason you do not want to put a long RF cable between the transmitter and the antenna is this. Coax is leaky and attenuates the signal. So by the time you get to the antenna, there might not be any RF energy to radiate out of the antenna. and remember this, the cheaper the coax, the more it will leak.

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Thanks, The RF cable costs is nearly 4 x as much as the audio cable, so I went with the audio cable.

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Extend the audio signal cables and do yourself a favor and order a ferrite filter to put on each end of the cables they're stupid cheap so why not go ahead and get them

There is actually a much better way to do it. Pick up four 1:1 audio isolation transformers. At the source end use one pair of the transformers to convert from the unbalanced output signal from your PC to a balanced signal and use a pair of 2 wire plus shield cables (one for each channel). At the amp end, use another pair of transformers to convert back to an unbalanced signal to feed the amps. This will eliminate almost all ground hum and noise problems.

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The isolation transformers I've used are only 3 or 4 bucks each. Started using them in a radio broadcast studio (14 studios) that I engineered for a bunch of years ago, and solved all sorts of problems.

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Cables have all now been run.  Both Cat 5 cables and audio cables are now working as they should.  Perfect FM reception - No "audio isolation transformers" or "ferrite filters" were required.

 

Controlling from my basement office/"Command Center" will work out so much better.  With one overlooked exception.  I often watch my Dish TV through my computer as I work.   Not going to be able to do that in the evenings once the show starts at the end of the month. :(   In a pinch I'll switch to one of my laptops, but I can't leave them on as they tend to overheat.  Either way, The office/"Command Center" seems like a great idea.

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LL

 

Just one question. Ok, so I assume you have your radio and audio wires ran they way they are going to be during the show. Are you telling me that all of your display is set up, connected and you did the audio test while the light display was running? In other words you have done a dress rehearsal.

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Let me re-qualify ..."Perfect FM reception - No "audio isolation transformers" or "ferrite filters" were required."... so far.   I'll be surprised if I get much interference, but will resolve it as it occurs. For the past 6-7 years, I have run all of my Cat 5 and electrical cables bundled together and have had no related show issues.  One exception - The FM transmitter does need to be powered with a circuit not used by the show.

 

I do miss the days when a simple SD card was capable of running the show.

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Cables have all now been run.  Both Cat 5 cables and audio cables are now working as they should.  Perfect FM reception - No "audio isolation transformers" or "ferrite filters" were required.

 

Controlling from my basement office/"Command Center" will work out so much better.  With one overlooked exception.  I often watch my Dish TV through my computer as I work.   Not going to be able to do that in the evenings once the show starts at the end of the month. :(   In a pinch I'll switch to one of my laptops, but I can't leave them on as they tend to overheat.  Either way, The office/"Command Center" seems like a great idea.

 

That's good to hear Tim.

 

I have a laptop that gets warm when in use so I prop it up towards the back end with a 1x1 strip of wood so the laptop can breath a little better. Made a big difference.

Just a thought.

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LL well I suppose you are one of those guys who must live a good life. Many if not most of us have to keep our wires separated and in some cases have to use those isolation transformers. Good for you.

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  • 3 weeks later...

OK, show is ago tonight & I can report that so far there is no noise or communication issues.  All RGB/DMXs & all LEDs flashing in perfect time & no static on the FM. All of my Cat5 cables, audio cables and electrical cables are run together in bundles.

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All of my Cat5 cables, audio cables and electrical cables are run together in bundles.

Mine too, with no problems,

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