Using two MX-850's with one MRF-350 (connected to RFX-250 antenna located safely away from all RF interference). All my components (except for the TV's) are in one room with viewing areas in different rooms hence my use of multiple RF remotes with one base station.

One of the 850's is an Orion with a manufacture date in 2006. The firmware is from Oct 2, 2008.

The other 850 is a narrow band version with "MX-850" on the bottom front of the remote. Firmware is from June 24, 2010.

Both remotes have identical programming (downloaded to remote from live-updatable MX-850 Editor software with Universal Data as of 8/31/2015).

I am having inconsistent operation of the RF (via MRF-350 base station) with my Comcast Xfinity box. BUT ONLY FOR THE NARROW BAND REMOTE. (Turned IR off to perform the testing). I am using Codeset 195, 202 & 203 for the box, the results are all the same.

The Orion remote seems to work perfectly once I've found the "sweet spot" in terms of the IR flasher output level from the MRF-350 (I'd say it's a little short of halfway on the dial). [Note -- the front blaster is OFF].

Yet, the newer MX-850N yeilds inconsistent results no matter what I do. I'd say only 1 out of every 4 or 5 keystrokes on average actually registers (sometimes, like with play/pause toggle, it works pretty well, maybe 3 or 4 of every 5 keystrokes work. But sometimes, especially with the menu and navigational buttons, it's worse with only one out of six or seven). Bottom line, inconsistent at best, and unusable in either case.

Did an experiment with this remote only. (1) Lowered the IR flasher output to minimum level possible from MRF-350, thinking the problem might be with IR overload. Box responds NEVER at this low output level. (2) Slowly increase, box responds once I get to about 25% but barely (ie: worse performance than noted above). Between 50% to 100% seems the same -- completely inconsistent operation as noted above, with 1 in 4 or 5 keystrokes recognized (sometimes it works better than that, sometimes not). (3) Even at 100% the results are inconsistent.

Note that when using IR, both remotes operate the cable box flawlessly (ie: pointing the remote directly at the component). So it's definitely an RF issue but the issue only affects one of the remotes.

End of the day, something weird is going on with the 850N and its RF, but only for this device (RF works all other devices just fine). The Xfinity box works fine with RF with the Orion 850 remote. It seems that the "strength" of the IR signal output from the MRF-350 base station is different between the two remotes?

Do I just chalk it up to some weird difference in the hardware (I know that the narrow band remotes have a different motherboard and newer firmware)? The IR codes issued by the remote are otherwise the same and I'm using the same RF ID# on the remotes & base station (ID #1).

I do know that Xfinity X1 boxes are notoriously difficult to operate, so this is not all that surprising. Thought I'd post my results to see if anybody has experienced anything similar.