Tvheadend

Hi,

can someone help me to find a way to downgrade. I'm in the unstable ppa and have now release 1284. I want to downgrade to 1257 (it was the version I had before) but I'm not sure how to do this. I found

sudo apt-get install tvheadend=4.1-1257

But this does not work

Can someone help

Thanks

S