Galloping Ghost & Pulse Proportional

[Phil Green]

A few retro RC enthusiasts are flying Galloping Ghost again after 50 plus years!
GG uses a single actuator to control rudder, elevator and optionally throttle from 
a single-channel radio. This was done by pulsing the transmitted tone, using
mark/space for rudder and pulse rate for elevator.  These variations in the
duration of the transmitted tone pulses gave fully proportional rudder & elevator
control though with some unavoidable interaction. Throttle was continuous tone
for high and no tone for low throttle, which also gave an inherent 'failsafe' on loss
of signal.

Its popularity was mainly due to its low cost - when few could afford the financial
outlay to 'go multi' from single-channel, Galloping Ghost offered a cheap
intermediate step with the advantage of being proportional.

Today we recreate the experience using a combination of a 'clone' GG actuator
3D printed by Tobe Kallner, and my on-board 're-coder' which converts your
standard rudder & elevator servo signals into mark-space and rate
controlled pulses exactly like the output of a GG receiver.

Tobe & I also have a rudder-only version which replicates the old pulse
proportional systems such as Adams and Testors.  
Here Otto demonstrates both systems:

 

 

 

Cheers
Phil

PS If you're thinking "where have I heard that name before?"   Otto is Mr. "Flyguy"   

 

Edited By Phil Green on 08/03/2017 13:42:19

[Chris Bott - Moderator]

This is completely fascinating Phil.

It's something I completely missed in my 'yoof". Transitioning straight from MacGregor SC to Walton propo.

[Former Member]

[This posting has been removed]

[XK50]

I recall seeing a homemade GG device controlling a model boat, at Bourneville, circa 1961.

The required variable pulses were generated, on the Tx side, by a sliding linear contact, operating along a triangular piece of thin copper sheet, wrapped around a quickly rotating wooden dowel, driven by a Mighty Midget motor. Slide left and get 100% mark; slide right and get 100% space.

I flirted with copying the idea, but at 14, it never got off the ground (in any sense).

XK50

 

[ron evans]

Hi Phil

The sound of the actuator thrashing about brought back memories of my Fleet two stick TX and Rand servo. Learned to fly with it in an Impala off the slope and with no motor noise, you could hear it  a long way out.

I discovered the failsafe after launching my Schoolmaster with the aerial down, and twenty yards out the OS10 throttled down and it made the best landing of the day without my helpGreat vids.

Ron

Edited By ron evans on 09/03/2017 18:22:07

[Gordon Whitehead 1]

The Tx pulser and Mighty Midget actuator described above by XK50 was in common usage in the 1960's up on Baildon Moor, where the Veron Deacon was a popular G-G controlled machine. Still at school, I flew only .5cc F/F and 1.5cc C/L back then, and watched the R/C activities with some fascination.

This thread has awakened some happy memories, and like Ron I had a Rand actuator in a Schoolmaster, which had an Elfin 1.49 for power. This was in the late 1960's. after I'd started working. My Rx was a Macgregor s/c superhet, and the switcher to drive the Rand was probably an RCME circuit published around the same time as the RCME Unijunction Tx I was using.

To set up the pulse rates on my home-made Tx (I forget the actual figures but it may have been around 2 pulses per sec for up-elevator, 4 pps for neutral, and 6pps for down) I used an RF harmonic from the 27MHz Tx in conjunction with our B&W TV set - colour TVs were only just coming in, but we couldn't afford a colour set until a few years later anyway. I tuned the TV to the harmonic, and could then hear the beeps coming from the loudspeaker, and watch the striations from the signal on the screen. I'd count, say, 5 seconds' worth of pulses - 10 pulses would be UP elevator, 30 would be DOWN, etc, and I'd adjust the pot settings on the Tx board to produce the required pulse repetition frequencies. Setting the pulse rates in this fashion wasn't a family-friendly activity as it was a process of trial and error, and an hour or so of beeps and twiddling would drive my otherwise very patient wife almost potty!

My next G-G plane was a lightened Phil Kraft Flea Fli, with dihedral increased to about 8 or 10 degrees each side for controllability. Power was an OS .15 R/C and the plane was a great success. Shortly afterwards and following much saving up by doing odd jobs for cash, I became the proud owner of a Futaba Digimax 4 in 1970, built a proper 4-channel Flea Fly with Enya .19 TV, and put the Rand in a boat for rudder control. The little cabin cruiser had an ED Bee Mk1 1cc diesel,with copper tube wrapped round the cylinder head as a water jacket. The engine is long gone,but for some reason I still have the flywheel for it.

Gordon.

Edited By Gordon Whitehead 1 on 09/03/2017 19:41:19

Edited By Gordon Whitehead 1 on 09/03/2017 19:42:31

[Doug Campbell]

Its not right having those bits flapping all the time. Whenever I see one I have the urge to shoot it to put it out of its misery