Comment 16 for bug 193848

I had the same problem with uploading qt sources (~240 MB). I wrote this into my ~/.dput.cf and now it works fine

[sppa]
fqdn = ppa.launchpad.net
method = sftp
incoming = ~%(sppa)s/ubuntu
login = brcha

Just copy the snippet above to your ~/.dput.cf file, change username (unless you have my private ssh key which is not likely :) ) and upload to dput sppa:<yourname>/<yourrepo> <somefile>.changes. My advice is to use regular ppa:x/y for transfers of smaller size since sftp doesn't show the progress indicator which is a cool feature to have :)