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Antenna combiner


nevo

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What are people using for combining Antennas for multi zone use?

My use would be for the very odd occasion like I had last week with 3 cameras and a long walk n talk with 100 extras vehicles crane etc .

If I could have put another set of antennas along the way would have been useful.

Im thinking DC powered with a small footprint The  one I’ve seen is the Wisycom CSA221

Which has 4 db of loss .

Are there any other manufacturers who make combiners at a reasonable price..... I don’t really need a active combiner 3k unit ...

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54 minutes ago, Mungo said:

https://www.rfvenue.com/products/4-zone

 

The only one (?) that really does what people like us need. Quite well built and quite versatile. Unfortunately rack size and only AC powered. There are people who have modified it to DC. In this forum there has been discussed this device a lot.

The input third order intercept is only -5dBm (minus 5 dBm),  according to their web specs of -35 dBm intermod products at -15 dBm two tone input. To convert to input third order intercept, subtract -15 dBm from -35 dBm for 20 dB difference. Add half of 20 dB  to -15 dBm input and you have a -5 dBm third order input intercept. That isn't great in today's RF environment.

Best Regards,

Larry Fisher

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Wisycom has an active antenna combiner and it works really well. But I believe it’s quite expense.

 

I haven’t used the passive version, but I’ve used other passive combiners and they have worked okay.

 

For optimal performance, you probably need some signal boosters before hitting the combiner.

 

 

Good luck

Fred

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4 hours ago, Mungo said:

https://www.rfvenue.com/products/4-zone

 

The only one (?) that really does what people like us need. Quite well built and quite versatile. Unfortunately rack size and only AC powered. There are people who have modified it to DC. In this forum there has been discussed this device a lot.

https://wisycom.com/products/product/mat288/

https://wisycom.com/products/product/mat244/

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Wisycom quotes "Output" third order intercept (Oip3) rather than the more useful "Input" ip3. The output ip3 number always looks better and therefore is commonly quoted. For instance, a device with a 20 dBm output ip3 (good) and 30 dB of gain (bad design), has an input ip3 of -10 dBm (poor). Specifically, high gain, low noise gain stages can have a good output ip3 but a lousy input ip3. And input ip3 is the important spec. Having said all that, the Wisycom unit is low gain, moderate noise, and high current. Looking at the 7 dB of gain, fudging a few dB of filter loss and 7 dB of splitter loss the input ip3 is probably about 14 dBm. All in all, good numbers. I just wish they would quote the more descriptive numbers.

Best Regards,

Larry Fisher

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