BNC Antenna Cable

howlingwolf487

Active Member
Joined
Sep 19, 2006
Location
Collingswood, NJ
Hello,
I am looking to move around my wireless racks. We have audio technica wireless mics. I was looking at cable (I need about 100ft). Do I need this?
http://www.bhphotovideo.com/c/product/352367-REG/Audio_Technica_AC100_AC100_BNC_to_BNC.html


or will this work?
http://www.amazon.com/dp/B0002J2N5E/?tag=controlbooth-20


I don't want to have to pay more than I have to.

Thanks!
Once you get over 50ft., quality 50-ohm coax gets mighty pricey.

Any reason you can't relocate the receivers closer to the area the wireless mics will be used in?
 

JD

Well-Known Member
Joined
Jan 1, 2005
Location
North Wales PA
The A/T system looks to be a 50 ohm cable, standard coax is 75 ohm. You would have a pretty big signal loss if you used the 75 ohm cable due to signal transmission miss-match.
 

Chris15

CBMod
CB Mods
Premium Member
Departed Member
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Jul 15, 2005
Location
Sydney, Australia
The A/T system looks to be a 50 ohm cable, standard coax is 75 ohm. You would have a pretty big signal loss if you used the 75 ohm cable due to signal transmission miss-match.
Well actually, in receive systems, the impedance mismatch causes a loss of about 0.18 dB.
[pdf]http://www.audiosystemsgroup.com/Which_Coax_for_Wireless_Mics.pdf
I'd just use RG6 and be done with it.
If you are using IEM, all that's out the window for that antenna cable, for that, 50 ohm ONLY!
If you have active equipment, eg. amplified antennas, active splitters, etc. etc. then my gut says you should be looking at 50 ohm, but I'd have to think more about the physics...

I'm not yet convinced that the moving them to the booth is a better option, if you have the existing infrastructure to make them work where they are.
What are you hoping to achieve in a move?
 

howlingwolf487

Active Member
Joined
Sep 19, 2006
Location
Collingswood, NJ
That's where they are now, but we would like to have them in our booth instead.
Why do you want them in the booth?

Monitoring/control?
Better reception of the transmitters?
Keep them away from wandering hands/fingers?

What make/model wireless receivers do you have at this place - you may be able to monitor/control them remotely. Also, are you using the sets of whip antennas that come with the units, or do you have a distribution system in-place? I'm assuming "no" because of what you're looking at purchasing. If coverage is a concern, then you may need to look into different types of antennas.
 

FMEng

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Mar 31, 2008
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Tacoma, WA
I agree with Chris. There is nothing wrong with using 50 or 75 ohm cable for receiving. The cables the OP asked about are probably RG-58 or RG-59. The losses of various cable types, per 100 feet, at 600 MHz:

RG-58 -10.6 dB, RG-59 -8.1 dB, RG-6 -7.3 dB, RG-8 -3.3 dB, RG-11 -3.7 dB, LMR400 -3.1 dB.

Basically, the fatter the cable the lower the loss, and 75 ohm cable is a bit smaller for roughly the same loss as a 50 ohm cable. Looking at the above numbers, I would go with RG-6 or better. 8-11 dB is a lot of lost signal., but 6-7 is probably fine, unless there are big splitter losses.

Which type I would choose largely depends upon what's available at a reasonable cost, and which type has an exact fit connector that uses a termination method I have the tools for. There are lots of great cables and connectors, but some of them require a $300 tool to crimp. It has to be something I will use repeatedly to make the tool investment worthwhile. Sometimes it makes sense to make a cable with the wrong connector and use an adapter. Clamp type connectors are OK where they won't take much physical wear, but crimp connectors take abuse better.
 

venuetech

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Apr 14, 2008
Location
AK,
Will the signal be unusable if the antennas are in or near the booth?
 

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