A couple months back, I bought the CM-4040, a 5-Element Yagi [NOT an LPDA like I first thought], when it was on half-price Sale, separated it from it's base and threw it on top of one of the four stacks of papers next to my Stressless Recliner with the intention to Model it. I just now retrieved it from what is now the MIDDLE of that stack, along with a few other pictures of Antennas I want to Model. I copied it and will cut out the Outline so I can trace over it, using 4nec2 Geometry Builder to construct a 4nec2 Model and let you know in a few days. BTW: After removing two screws, I see that the "Fatter" Rear Element is a REFLECTOR, with the ACTIVE Dipole in front of it fed thru a very small and hence somewhat inefficient [probably 1:1] Ferrite Transformer Balun and the three smaller Elements on the Front are Passive Directors....which are TOO CLOSE together for Optimized Gain.
BTW: It is NOT designed for OUTDOOR use. Unprotected Coax connection to Balun can let in moisture [degrading the short piece of Coax as it seeps inside] and connection to ACTIVE Dipole is via a low-reliability pressure contact between pieces of Copper [connected to Other end of Balun] and some sort of metallic etch [which already appears to be degrading] applied to the two halves of the Dipole.