Exactly. FCC area using US model AF-2X. Cable loss approx 1 dB, so power conducted to the antenna is 1 dB less than power from the radio, so I'm expecting 27 dBm out of the radio.
I'm in the 4X modulation range. Data sheet states max suggested Tx for 4X is 27-28 dBm. The radios simply don't allow more than 24 dBm (at any modulation) with the current firmware. It looks like this will be resolved soon, which is awesome. On Fri, Jul 29, 2016 at 3:27 PM, Ken Hohhof <[email protected]> wrote: > Is this in FCC area? FCC rules for 2.4 GHz PTP are 30 dBm max transmitter > power with 6 dBi antenna, for a total +36 dBm EIRP. Then for antenna gain > above 6 dBi, you have to reduce xmt power 1 dB for every additional 3 dB of > antenna gain. Also this is independent of channel width, it’s not dBm/MHz. > > So you have an 18 dBi dish, that’s 12 dBi of additional antenna gain, so > you would have to reduce xmt power by 1/3 of 12 dBi or 4 dB, to +26 dBm, > and max EIRP would be +42 dBm. > > How many dB do you figure you’re losing in the long cables? I’m unclear > on whether cable loss counts against xmt power or antenna gain. If you’re > losing several dB in the cable, I can see where you’d want the full +30 dBm > xmt power from the radio. > > *From:* Christopher Gray <[email protected]> > *Sent:* Friday, July 29, 2016 1:20 PM > *To:* [email protected] > *Subject:* [AFMUG] UBNT AF-2X Problems... Where Do You Go For Help? > > I've had an open ticket about the AF-2X for over a month. I have not been > able to actually work with anyone on the issue. It has been "escalated" but > without any positive results. > > Is there a better way to talk to someone about the airFiber? > > The spec sheet says a US AF-2X has a maximum Tx power of 30 dBm... but it > only goes up to 24 dBm. [I'm running an 18 dBi dish on one end with long > cables, and I need the additional 3 dB Tx power). When changing channel > width, the Rx power does not change (Rx power is usually measured in > dBm/20Hz on most UBNT hardware, so power usually goes up 3 dB when halving > the bandwidth, but I can't get a straight answer as to whether they use the > same units on the AF line). > > Long story short, I'm going to have to get rid of this AF-2X hardware and > switch back to ePMP. The AF-2X would be the better choice if I could get > the power levels I need to make this link work. I would much rather solve > the AF problems.. > > -Chris > >
