Intermittent antenna 1 (ANT1) and no AM reception

When I press and hold the set-up button, I can get to a screen that lets me check the signal for the radio. I have a more rare RNS-510, but I think it also works for the RCD-510. Checking that screen for two days now, it seems I have an intermittent ANT1. It was "off" yesterday with no AM reception and then "on" today with "Good" or "Weak" AM reception. ANT2 was "on" both days, but one antenna doesn't seem to be good enough for AM reception. It was fine on FM with only ANT2 "on". Sirius also worked fine.

Questions

1. Where is ANT1?
2. Where is ANT2?
3. Has anyone dealt with this before?

Thank you for your help!

Did you notice the current thread in this forum:

http://forums.tdiclub.com/showthread.php?t=460631

"Suddenly have bad/no AM reception?" It might help. Cheers

That's my fault. I tried to make a better thread with a more specific title. The other thread is mine.

The good news. My ANT1 has been "on" the past 2 days so I have AM radio! I didn't scan the car yet with VCDS to see if faults are stored for the two bad days with ANT1 "off", but I will.