I have a number of cassette tapes which have 2 or 3db difference from one channel to the other. It’s just an effect of the old stereo I used to have. I have been able to record successfully. You can see on the Audacity screen that one channel is lower level than the other. I tried to normalise with and without the “normalise separate” tracks box ticked and yet R channel is lower vol than the other. How can I normalise the “lower than the other one” channel to be the same as the other. Can it be done?
The “Normalize stereo channels independently” option will normalize left and right channels to the same peak level.
However, note that “peak level” is not the same as “loudness”. If there is one peak in a channel that is higher than other peaks, then that is the peak that is used to set the amount of amplification.
So… Normalize the track with “Normalize stereo channels independently” selected, then listen to the track. If it still sounds "out of balance, then adjust the Track Pan control (http://manual.audacityteam.org/o/man/audio_tracks.html#pan) so that it sounds right. The track pan control can be adjusted during playback. Then export the track.
OK thanks, will give that a try.
I tried a different approach (having read a bit of the manual). I separated the tracks into L & R and then re-ran normalise. That seemed to allow the “low” track to come up a bit (only as measured by eye on the graph - not scientific, I know). This may have been a misinterpratation by me as I wasn’t looking closely and I did not need to separate the tracks again having re-joined them before I did the next bit.
I noted your comment about “peak” so had a closer look at the “low” track. There were two very short spikes which were close to the max. So I zoomed right in and cut out the peaks. They were so short, couldn’t hear that they had gone. Ran normalise again and the “low” track was boosted appreciably (again, by eye).
So my guess is that these two almost-instantaneous peaks were providing the upper limit for the normalise process. Clip them out so that normalise worked on the more normal levels on the rest of the track and bob’s the relative of your choice.
Indeed - a good “guess”
The Amplify and Normalize effects are both purely arithmetical and have no “smarts” like the human eye/brain combination 
Glad you found a way to sort it - and thanks for feeding back your solution.
WC
PS - if the peaks were less than 128 samples you could have used the Repair effect to fix them - see: Audacity Manual
Thanks for that tip - I will experiment with that if a similar issue arises.