Zenith Bulldog -Electronic Speed Control with an odd twist

[GoMachV]

Picked these up off eBay thinking they were interesting but discovered something else really cool about them. I worked at a major hobby shop about a block from their shop. I am going to reach out to my old employer and see if there was a relationship, as I believe there may have been based on the fact that our show also made speed controls and chargers under the Lightning Bolt name.

Anyway, here are scans of the manual and a pic of the unit. These are an electronic speed control, but they are servo driven. They feed power back to the receiver for power but no signal wire. The arm on top is connected to a potentiometer.

[TRX-1-3]

The heatsink I just ruined is a Bulldog product. Looks very similar in manufacturing. Square fins with round "thru-bar"

Just found it kind of wild that two obscure Bulldog references occurred within two days.

[GoMachV]

One was obviously blown so I yanked it apart. Yikes. Breadboard

[1911Colt]

I noticed the Beaverton address. That was the home of Tektronix. I wonder if this could have been a side project for one of their engineers?

Breadboard!