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Author Topic: How to TX into/out of heavily shielded buildings?  (Read 3317 times)
KCJ9091
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« Reply #15 on: March 16, 2012, 06:38:26 AM »

The trade marked name for leaky coax is "RADIAX"

http://www.commscope.com/andrew/eng/product/trans_line_sys/coaxial/radiating/1206639_13611.html
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WA3SKN
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« Reply #16 on: March 16, 2012, 08:10:28 AM »

This all depends of frequency (or wavelength)... and you probably do not have any choice in that.  VHF will have less loss, but UHF and microwaves will "bounce around" more.  You will have to do  some testing to see just what works for the building in question.  Multple repeaters will cost a lot more than a simple "two connected antennas" design.
Can you give details?  What radio service are you trying to use here, what frequency, etc... and are there any windows or glass in the building?  How many floors?

-Mike.
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K6AER
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« Reply #17 on: March 16, 2012, 01:51:40 PM »

Look into building BDA's. By Directional Amplifiers. They have them for cellular as well as public safety radios.

You can buy them from Tessco. Price is from $400 up thousands depending on the band.
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W0FM
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« Reply #18 on: March 16, 2012, 02:39:35 PM »

I have had mixed results with the "smoke and mirrors" of passive repeaters over 37 years in the business.  For the money invested in a passive repeater, it's certainly worth a try, but don't count on it. 

As Mike suggested, a decent BDA (B-Directional Amplifier) is the best fix.

Terry, WØFM
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KZ1X
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« Reply #19 on: March 16, 2012, 04:04:19 PM »

As it turns out, there's an entire industry built up around products for this application. 
The generic term for such systems is 'indoor DAS.'

Here are just a few links to suppliers:

http://www.innerwireless.com/

http://www.powerwave.com/

http://www.te.com/en/industries/wireless-coverage-capacity.html

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WX7G
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Posts: 6049




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« Reply #20 on: March 17, 2012, 04:00:21 AM »

The links provided appear to be for systems that employ different TX and RX band portions, such as cellular telephone. They do not amplify the same frequency in two directions.

Can the campus radios be used with a repeater? The repeater would sit atop the building and have both the RX and TX antenna ports connected to antennas inside and outside the building.

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