We know the 9N-9600-C1 Air Cleaner was supplied by DONALDSON, used on early 9Ns, alternately with the 9N-9600-C2 UNITED model. At some point during 2N production, the supplier was changed to the C-3 unit, logo was a stamp-raised letter "H" in two places. The top cover screen housing was removable, secured with a wing nut -see picture. Did we ever establish who the "H" or "H-H" supplier was? The 8N-9600 was supplied by ( same, redesigned?) marked with "H-H". I also believe we established "H" was NOT HARCO.

Tim Daley(MI)

The 9N-9600-C3 was an H-H with a tangential V-clamp. The one with the two toggle clamps was the 9N-9600-D. The United with the "U" was -C2. We knew who made the H-H cleaner, but I can't find it now.

Yes, I recall seeing someone post the H-H supplier but could not locate it in our archives here. My early (1947) 8N air cleaner has the H-H logo, with a square cup, but the 1949 lime-green Dealer service manual for mechanics, circa 1949, shows the air cleaner with a round cup. Maybe that was a UNITED supplied part?

Tim *PloughNman* Daley(MI)

Houdaille-Hershey.

Fun fact: during WWII, Houdaille-Hershey produced the nickel-plated pipes used in the gaseous diffusion process of enriching uranium at the Oak Ridge site.