# Distance between 2 Force 200 on same pole

Hi,

Just want to ask if there is a standard separation distance between two Force 200 radios in 1 pole?
Or is it okay if they are near each other?

Thank you.

Hi,
It is recommend to have a 1.5 meter separation ( Horizontally & vertically ) in ideal situation b/w two radios.

Hi,

Thank you.

It is recommend to have a 1.5 meter separation ( Horizontally & vertically ) in ideal situation b/w two radios.

Just curious, is that due to noise from the electronics of the radio itself causing interference ?

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Yes- this will reduce the effect of EMI

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So, dumb question, if the radios need to be 1.5m apart to prevent them from interfering with each other how does the radio not interfere with itself ?

The radios are TDD - time division duplex, meaning that they are in transmit mode or receive mode, but never can they be in both at the same time.

For everyone reading this, the 1.5m separation makes some assumptions. Since every device that we co-locate on towers has a directional antenna of some fashion, so anytime we mount antennas on towers, they have some kind of relationship to each otherâ€¦there is free space loss between them, as well as the directivity of the antenna contributes to the isolation that 2 antennas have in relation to each other.

1.5m of separation provides about 50 dB of free space loss as a rule. Then side to side isolation of directional antennas can range from 10dB to 25 dB or moreâ€¦you have to consult the antenna polar chart to see what the value might be in the direction that your antenna(s) are from your antennas you are calculating. For this example, lets assume we have 10 dB from each antenna. Add the losses up, and we have 70 dB of isolation that 1.5m separation gives us with the Force 180 antennas.

Remember that the more unsynchronized radios we add to a tower, each one contributes to the noise floor rise on that site. Best practice is to use as much GPS synchronization as you canâ€¦using the same TDD split on each system so that all radios co-located are in TX mode at the same time, and RX mode at the same time. In this situation, you do not have to worry about co-located equipment contributing to noise rise. For example, if you have ePMP 3000 APâ€™s synchronized with GPS on a site, use a PTP550 or PTP670 for backhaul, both can be GPS synchâ€™d, and TDD radio set similar to the ePMP3K.

Hope this helps with understanding what might be happening on your siteâ€¦any questions, please ask, as there are many true RF experts in our community.

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I assumed OP was talking about subscriber radios since he was asking about F200â€™s on a pole. If so, then he could mount 100 of them on his pole and as long as they are all talking to the same TDD AP then side lobes nor front to back nor free space or TX power is relevant because not one of them will ever TX while another is trying to RX.

So I asked specifically if the problem due to â€śnoise from the electronics of the radio itself causing interferenceâ€ť

Cambium Sreejith said yes â€śthis will reduce the effect of EMIâ€ť so either Iâ€™m misunderstanding him or he misunderstood me or we both misunderstood or this is about EMI coming from the electronics not the antenna.