The pictures and videos of home made set ups that I have seen, use the small 1gal. shop vacs.
Mike.
My You Tube
mbinsewiThat hose gets connected to a vacuum.
My guess would be a hand held Vacuume Pump used in the auto repair bussines.
Cuda Ken
I hate Rust
Right at the beginning of the video that Carnegie Falls posted, there is a picture of the set up. A jar with a cover, and two holes in the cover that the tubing or hose fit into. One tube goes to the bottom of the jar, that is the ballast sucking line, the other tube just goes through the hole in the cover, and stays at the top of the jar. That hose gets connected to a vacuum. It doesn't have to have an air tight connection to the vacuum, or you might get to much vacuum power. Turn on the vacuum, use the hose that goes to the bottom of the jar to vacuum with, and the loose ballast stays in the jar, and doesn't get sucked up into the vacuum.
EDIT: I think the version in the MRR, the vacuum was connected to a plastic jug, then a line went from that to the jar. That might have helped control the vacuum power, by giveing the system another brake in the suction process. Others I have seen, they use painters tape to connect directly to the vacumm. It kind of lessons the vacuum suction.
sorry, duplicate post
I think your best bet might to order that back issue if you are able. Here's a good video that shows someone using one they made, if that helps.
https://www.youtube.com/watch?v=_r472H_eYmg
I am looking for information on how to build the ballast leveling machine mentioned in an article in the January 1978 MRR on page 108.