General control line discussion > How I got my start in the hobby

Some Unusual History

(1/2) > >>

FLOYD CARTER:
I think it was in 1956.  I lived in Downey, CA and not far from Bob Dunham's fledgling ORBIT R/C business, which was run from his home.  Bob asked me to come over and share ideas on R/C equipment.  He wanted to produce a ten-channel R/C outfit, but he was having trouble getting his receivers to work properly.  Well, I ended up re-working his receiver design to make it more sensitive.  At the time, all radio control stuff was operated with tuned reed banks.  A 10 channel reed bank would control five servos.  I bought the best reed bank I could find, and built this receiver for Bob.  He later changed some of my transistors to smaller ones and he had a printed circuit board made up.  I never learned how many 10 channel radios he finally sold, but must have been quite a few.  The best servos made in those days were by Howard Bonner.

Shorts,David:
We're those the radios that if you yelled at just the right frequency you could make the service move? I started rc about 82, when everything had moved to 72 mhz.
How about c/l, what was your first plane?

FLOYD CARTER:
Reed transmitters had 10 audio tones modulated onto an RF carrier (Amplitude Modulation).  Each audio tone activated a resonant reed on the receiver reed bank.  Each reed had contacts (like a relay) connected to a servo amplifier.  A small current passed through the reed contacts to the servo.  Two tones per servo, like elevator--up and down--and absence of any tone command caused the servo to return to neutral.  There was no "trim".  Servo trim had to be adjusted on the ground by adjusting linkage.

Reed type servos required three separate voltages;   + 3 volts,  - 3 volts and  - 1.5 volts.  The battery pack was SEVEN cells, either alkaline or NiCd.  Quite heavy!

The transmitter had 10 buttons for control.  Or else  five "telephone type" lever switches.  Controls were either Neutral, or else Full Control, one side or the other.  "Proportional" control could be simulated by pulsing the switch On and Off rapidly, causing the control surface to "dither" between neutral and full control.

Managing a reed bank R/C was much more difficult than the later Proportional radios.  Precision R/C flying was nearly impossible.

My first C/L plane was an old free flight model converted to C/L.  It was called "Spook 48".  That was 1945.

phil c:
I had an Orbit 10 channel reed set around 1970.  Was getting into RC for something different, while building combat planes for fun.
I actually flew a plane with it.  There were still some very helpful guys in the Twin City club.  Some were still flying reeds, digital proportional was just getting affordable.
I remember one time watching one of the better flyers flying with a reed setup, and somebody else had the back of the transmitter off, re-tuning the reeds so it could be landed.

Later on I built a MAN outfit and learned to land.  Initially though it was exciting.  One kind of windy day I was having problems keeping the plane pointed upwind back to the field.  It finally got so far away I could barely see.  The best all around flyer in the club grabbed the transmitter and another guy had binoculars and was telling him which way to turn to keep it coming back.  The controls are reversed, so it's tricky.  They did manage to get it back in one piece to a nice landing, than God.  More money than I could afford to lose.

FLOYD CARTER:
Phil.  A 1970 Orbit 10 channel reed outfit might have been a later revision of my original circuit.  I'm not sure who helped Bob Dunham with later electronic design.  Bob was not capable of electronic design.

For those who might have known Bob Dunham, he died of lung cancer.  He smoked almost constantly.

One of my own early home brew R/C outfits was a 10 channel reed system with a very large transmitter.  It was often necessary to weekly re-tune the audio generators in the transmitter because they would drift slightly, and the reed bank in the receiver was very narrow-band.  Just a few cycles off frequency and the reed would not vibrate!  It was common to lose one or more channels while flying due to circuit drifting.  Crashing in those days was common due to radio problems.

Navigation

[0] Message Index

[#] Next page