Bloomberg is too expensive for me (~$500/mo or so?). At the moment, I've got to do it the hard way--I have a spreadsheet of conversion ratios, and I plug in quotes I can get through Schwab. This pain has led me trading in smaller size on the treasuries, or sticking to Eurodollars.
unfortunately $17k/mo - but it is still worth it. I can't imagine trading in size without it - it would be like being blind.... good luck... p.s. function on Bbg is FH <Go>