Epmp 3000 back to back separation

Hi all, I have about 4ft feet back to back separation between epmp 3000 radios. Now I have seen on the forum that say this is not enough in frequency re use situation and others say it is… I am leaning to the not side. So, if I cannot get these further apart is there a way to shield them from each other… an obstruction in between them? I am using cambium 90 degree antennas.

We have some of ours on 18" face tower, with some struts so that they are 3’ Back-to-Back. That works fine where we have them, with working GPS Sync, configured correctly, and with good F/B sectors (Cambium sectors).

In my opinion 4ft from the back of each antenna is not enough in most cases. We place them a minimum of 2m (6ft4) back to back and this ensures that they are not in each others back lobe and fully within the back null. Each antenna manufacturer will give you a chart showing a back lobe. All antennas have one its just how large.
Since we use KPP antennas, 2m is sufficient.

The radios themselves are very well shielded but poor quality cables and connectors can cause leakage. For short runs LMR195/LMR200 is good but anything that needs to go more than 1m we use LMR400 from a trusted source. A good provider will make sure you get a good quality cable. For the most part we mount the radio to the stand-off that the antenna is attached to and keep the cables short.

Wonder why it would matter if using Sync.

What problem are you having that you’re hoping to solve by adding a little bit more separation between radios? I really have to say that assuming sync is working, and you’re using good antennas, or the OEM Cambium antenna… you’re not going to have a night/day difference in performance by simply moving them another foot or two apart… in fact, I would bet money that you really won’t see any difference.

In past discussions other forum users had commented to me that improper back to back separation can cause issues as self interference which in turn can cause poor modulation. I did some SA on the two radios that are back to back and the east facing one had the west facing one show up in the interferer list which in turn left me to wonder if this is a possible issue.

The same forum users said even with using sync they need to have proper back to back separation.

We are using Cambium 90 degree sectors with the epmp 3000 radio, as per cambium 3ft is sufficient.

We are using Epmp 3000 radios with cambium 90 degree sectors, so we used the supplied mounting and RP cables that come with the radio and antennas.

I appreciate all of your replies!!