MC ABC LOF error

Hello did 10.5 firmware on 820 radios break something with MC ABC?

We are using 80MHZ 1501 script.

We have just upgraded 2 pair of Trango apex lynx links to new 820C links. Great RSSI dialed into exact rssi expected on 1st link but can't get the MC ABC LOF error to clear, MC ABC keeps going from up to down and back and forth on both sides of links. We have 2nd set we are getting ready to aim in and getting the same error that won't clear on this set of radios as well. All 4 radios are running new 10.5 f/w.

We have multiple other links running 9.7 f/w with MC ABC with no errors.

I think our next step is to start downgrading f/w on these radios was checking if anyone else has run into these errors

According to the 10.5 Release Notes, at the bottom of page 24, Script 1501 (80 MHz Script), "80 MHz scripts do not operate in Multi-Carrier ABC mode."

I hope this helps!


Hi Dave, what are your script settings?  Technically a 1501 script should have a maximum profile of 8 if using Adaptive Modulation.  If you change this, I would change the far end first, since the scripts need to match in order for the link to form.  This may also reset the radio interface.

Also, do you have the Adaptive TX power admin (ACM) enabled?  This enables the Adaptive Coding and Modulation feature to change power based on modulation.  It is a two step process: enable Adaptive Tx power admin, hit apply, then change the Tx power to maximum for the range (typically 26 or 27dBm).  The operational power may not change, but the radio will be able to use higher power.

Ok thanks guys missed that note on pg 24. Radios shipped with 10.3 loaded which I know they pulled that f/w. So I had updated them to 10.5. I will downgrade them all to 9.7 as we use the 80mhz script and we use MC-ABC. Any idea if Cambium will fix MC-ABC to work with 80mhz script in future f/w updates ?

Hi Dave, I don't want to burst your bubble, but, technically, MC-ABC support on 80MHz wide channels has never existed.  You will see the same information in the 9.7 release notes.  However, I have many customers running this configuration without issue.  I'm thinking that your script settings (too high of a profile) and/or ACM settings are causing issues.  I personally would stay at 10.5 and double-check some radio configuration parameters.

Also worth monitoring are the MSE, defective block counter, signal level and MRMC statistics under Radio>PM & Statistics.