I was listening to "Hey Jude" today and Paul's vocal sounds very compressed to me.  I think I can hear him "working" the mic, and of course he has great singing technique, but besides that I think I hear a fairly heavy compressed vocal.  What do you guys think?  What settings would you use to imitate it?

With most people 4:1 at -10 or -12, but Paul was a bit of a screamer at times, so maybe as much as 8:1 at -12. The rest of the settings are hard to say.
 
Bill

Wayfarer
With most people 4:1 at -10 or -12, but Paul was a bit of a screamer at times, so maybe as much as 8:1 at -12. The rest of the settings are hard to say.
 
Bill

That's a good starting place.  Thanks!

Engineer Geoff Emerick always used the Fairchild 660 limiter on vocals and drums. Backing tracks and Paul’s bass were processed with the EMI-modified RS124 Altec compressor. With a fixed attack time and six-position recovery switch, the Altec had a unique Hold control. 
 
Abbey Road engineer Norman Smith's favorite compressor for recording and mixing was the old Altec 436C
http://recordist.com/ampex/schematics/altec/436atl10.pdf
 
Geoff Emerick:
Geoff's favorite compressor was the stereo Fairchild 670. It was nothing like the Altec, being very subtle in nature, unless pushed (as on Revolver) and then it gave a "sound" that we all know from thousands of mixes from the 1960's and beyond....A clean one is worth around $25,000.00 these days
 

batsbrew
Geoff Emerick:

if anyone hasn't read his book yet, do so, it's a great read https://en.wikipedia.org/wiki/Geoff_Emerick#Here,_There_and_Everywhere

Thanks BB.  I did not know about the Altec.

Apparently Hey Jude was recorded at London's Trident Studios to take advantage of their new 8-track machine that EMI (i.e. Abbey Road) had not yet caught up with. But when they played back the mix at Abbey Road, the EQ was all wrong and took a lot of correcting so they didn't use Trident again after that.

Kev999
Apparently Hey Jude was recorded at London's Trident Studios to take advantage of their new 8-track machine that EMI (i.e. Abbey Road) had not yet caught up with. But when they played back the mix at Abbey Road, the EQ was all wrong and took a lot of correcting so they didn't use Trident again after that.

Excellent point (and one I had forgotten).  Thanks!