Odd BH20 signal strength problem

Hello forum, I have a 2.4 BH20 pair running software 8.2.1 on P10 hardware. This is a short link of 0.5 miles. When the link was installed it had excellent received power levels on both ends (in the -55 to -60 dBm range). Today I noticed that the BH slave has a -73 received power level while the BH master is normal at -58. According to Prizm logs, the BHS received power gradually fell off over a 1-day period right before Christmas. A visual inspection of the equipment yesterday showed that nothing had blown out of alignment.

Any ideas?

2.4 interference in the area?

Have you done a Spectrum test yet to see if anything has changed?

We take a few screen shots of the spectrum tests as we put up radios that we if we see an issue we can perform another spectrum test to see if anything has drastically changed. Just a thought.

I haven’t done a spectrum analysis yet, but I wouldn’t expect interference to cause a lower received power level. Increased jitter, switching between 1X and 2X, and poor linktest results, but I’m not seeing any of the above.

Should try it anyway to see if there is interference on the same band that you are using or the surrounding freq’s.

My question is how interference could cause low received power. The only thing I can come up with is receiver overload causing the automatic gain control circuit to pull back the RX gain, which shows up as a lower received power level. Has anyone had this happen with a Canopy system?

Do a spectrum analysis at both ends. Turn off any 2.4 BH Masters as well as any 2.4 AP’s.

This way you have a baseline, and it may reveal that you in fact do have interference (which is my guess).

.5 miles - I assume there are no reflectors?

No reflectors, but there are 2.4 stingers on both ends of the link.

I will try to do a spectrum analysis tonight after business hours.

I’d swap out the stingers one at a times, could be water in the connector, or could be mis aligned as well.

You say they are P10. Its possible you have a BH going deaf. This is a known canopy issue that they claim is now fixed but I still see it.

I did a spectrum analysis and the noise floor was high, but not that bad. The RX power on the one backhaul has returned to normal levels (at least temporarily). These links are getting changed out with different equipment ASAP.