Some or all of the '96 and '97 model machines came from the factory with a yield monitor that used weight and unloading time to figure out yield but other than that, yield monitors had to be purchased and field installed.
I have one in a box here somewhere that appears to be new. I could sell it to someone who needs one. It looks like it combines all the functions and controls and monitors the speed of everything in one little box. Written on the box is $630 new.
My suggestion if you want GPS and datalogging is get the NH yield monitor but do not get a factory datalogger. Instead use a Ag leader Insite unit. It can get the moisture and mass flow readings from the CAN-bus. You can then hook most any GPS reciever to the Insite unit directly. There is only one or two recievers that can be attached to the CAN-bus for the combine datalogger to work with. The Isite allows for direct connection to the reciever instead of thru the CAN-bus. The other option on 2005 and later CR's is using the CaseIH Universal Display for the datalogging but I'm not sure if all Universl displays will allow for the software or if it must be the large screen single card slot type. I think the large screen dual card slot type will work but I am not certain. Although you would be back to needing the CAN-bus compatible GPS reciever.
Maybe I should have mensioned that the NH yield monitor sensors, the moisture and the mass flow are built by AG leader for NH specifically. I just suggest getting the NH factory installed sensor system then adding the Insite and GPS reciever in cab. The Insite connected with the CAN-bus you have minimal wiring and no installation to do as well as having the NH Infoview based on-board diagnostics for the sensors.
I'd suggest an Agleader. I'd also strongly suggest mapping. You do not need an expensive GPS reciever when just yield mapping. When mapped, the data will make sooooo much more sense!
We put an Agleader PFAdvantage in our '52 this fall and were extremely happy with it. It is easy to use and understand. I was looking for a yield monitor only at first, but after looking into it decided to go for the mapping too. Now we can see which hybrids do well in what soils and where the weak spots are in our fields. We can also see how the variable rate fertilizer is working. Our seed dealer found a used monitor and GPS receiver for us. We had to by a new wiring harness and sensors. The whole thing cost about $4500. So far it was well worth the money.
Sawdust, I have a Fieldstar with moisture for sale, current model. Off an R62. I have run the Fieldstar and an Agleader and would be willing to visit with you about them.