In order to use a variable capacitor in this manner there would have to be an oscillator that it was "varying" in frequency which would have been compared to the input signal of the servo. Yes, the servo does appear to be incomplete and would probably better serve for parts to repair whole and already assembled John wrote:The servos differed from what we use today in that the "feedback" from the output shaft turned a variable capacitor and nowadays I have seen them use variable resistors, such as a volume control knob. (Or, it could be possible that Heathkit used an external circuit board or circuit was a part of the receiver board.) Plus, screws are missing. You are also missing the miniature circuit board that went with the servo. The change in resistance was used for feedback. they appear to be too thin for that, and without additional photos showing the top side, appear to be only a part of potentiometer.Īs the servo output shaft was turned by the motor, the geared potentiometer wiper element would move along the element, changing its resistance. Or, they are trimmer potentiometers with a thin wiper element on top. It is missing the housing with wiper element and shaft that was fitted with a gear. They are missing the mechanical portion with shaft, housing and wiper. These are the small circular circuit boards with 3 solder tabs and a deposited resistive film on the other side of the board. You have what looks like 1 complete feedback potentiometer (variable resistor) on the left and 2 potentiometer circuit boards that form the bottom of the potentiometer, one on the left and one on the right. Other than that, if there is any interest in the parts, please let me know or they will hit the ol' bin in the sky. I do not honestly know what the parts all are. There is some sort of 'dial' under the envelope. I apologize for my verbosity and if there is an omission, it's because I'm.įorgetful wrote:As for the servo parts, I know not too much other than it is not complete. Perhaps I am showing my age but nowadays this is not done much anymore. We also built our own bicycles from parts if our Father was not very affluent.
Old all band graymark radio tv#
I built a Conar brand VTVM (vacuum-tube volt meter), AM radio and a tube-type black-and-white TV when I was a kid. You could build your own tube-type CB transceiver among other things. There was also LaFayette which marketed electronic kits. Heathkit ended up being bought by Zenith. Usually they might have two or three problems that would manifest intermittantly, a good solid whack with your fist would make them go again! I have spent many a day repairing - well, actually, re-soldering kit-built Heathkit color televisions. When Futaba servos became available it was a major upgrade.īack in the day it was possible to buy as an alternate to the kit that you built yourself, a factory-built item that normally worked much better. One particular "feature" was that it might change settings depending on whether the wing, with its' aileron servo was assembled to the plane or just the fuselage was sitting on your bench.
You had just built your own CB transmitter and receiver! Do kids (or older) do this nowadays?Īnyway, it was not that great of a deal compared to today because the servos would "hunt" if mis-adjusted, or the temperature changed, or the carburetor throttle linkage was metallic. No big deal since you had built the whole setup - transmitter, receiver, servos. If it had had a metal tip it would not have been practical as the metal would have affected the tuning, no way would a screwdriver have worked. The white nylon "tuning wand"that the OP has in the picture was for "trimming" the oscillator in each servo. This was actually handy to center the servo to where the sliders were opposite each other in mid-travel. On my system there was not a rotating shaft to which you mount a servo arm but two linear "sliders", going in opposite directions, sort of like a push and a pull. In comparison a variable resistor "varies" DC voltage, which simplifies and makes more dependable of a system. The servos differed from what we use today in that the "feedback" from the output shaft turned a variable capacitor and nowadays I have seen them use variable resistors, such as a volume control knob. Beautiful blue crinkle paint transmitter. Also, if I remember correctly it was 27-Mhz, since it was a Citizen's Band radio.