sotonflyer

Phil_G, Nice pictures! I have a Staveley single channel TX & RX - the one that used a coded signal with a red lever for left/right on the TX and quick blip button.

What is the 'Wee Willy' glider? is it an own design? I have never heard of it.

phil_g

Wow I'd forgotten about that one until now - yes it did the press for right & press-release-press for left automagically and did it also do the quick-blip & 3rd position too?

The Wee Willy was designed by Phil Scaife, one of the founder members of the Sheffield Society of Aeromodellers, he was chairman for a good while. It was a basic parallel chord, pianowire-joned clark-Y wing banded to a slab fus. Balsa & tissue, as was everything then. At the time it became the clubs standard single channel trainer, and many were built.

I wish we'd taken more photos in the old days, but photos were quite expensive then, and you had to take the film in and wait a few days before collecting the prints! Seems so archaic now!

Cheers & thanks
Phil

sotonflyer

Hello Phil,

It did have a micro-switch for quick-blip but no switch for 3rd position. However, it was 'easy' to get 3rd position, by moving the rudder lever left immediately followed by right. Note: only very old RC aeromodellers will have any chance of understanding this last sentence. My transmitter is in near perfect condition, as if it just left the shop, and the whole system works. It was designed for a compound escapement like the Elmic Compact. I will take a photo of it tomorrow and post it. However, I only just got my own digital camera at Christmas and still have archaic film to develop.

If you could get hold of a plan for the Wee Willy (unlikely I know) I will build one and put the Staveley single channel gear in it. If you remember the Wizard of Oz (WoO) slope soarer I have one of those flying with old MacGregor single channel gear and Elmic Compact escapement.

Thanks,

Pete

HighPlains

My Feedback: (1)

How is any of this DIGITAL PROPORTIONAL HISTORY? Analog proportional was considered a dead end approach by 1965.

iflyj3

My Feedback: (7)

Let's see, one push for right, two pushes for left and three quick ones for throttle....Yep, that is digital

magone

Hi everyone! Magone here. I've Been reading this stuff and find it very interesting.
All this stirs a desire I've had ever since I moved some years ago. What happened was a box of magazines got lost in the kaos as moving goes. That box contained all the plans for the DIGITRIO propo system published in the Radio control modeler magazine written by Ed Thomson. They offered those plans in pamphlet form of which I obtained a copy. Lost with forever. For my own curiosity if nothing else (I would like to complete and fly the DIGITRIO system. If any one out there who just might have a copy could email it to me, I would be very willing to pay him/her for his or her time and trouble. Email address is [email protected]
Thanks loads to those who can assist. George Jenkins AKA Magone.

jaymen

I have the issues that cover the transmitter, and the decoder section of the receiver, do you have a partially completed kit or are you wanting to go at it from scratch?

magone

Hi there Jaymen!
Goooood to hear from you!
I have recently retired and now have time to start working on some of my pet projects. One of which was to get a DX7 Specktrum radio and get back to the flying field. This is one awesome radio! Never had a single hiccup or glitch.
Iv'e been going thru all my old stuff from the 60's and 70's but could not find the single stick orbit transmitter I had built up. I was hoping Icould save us some trouble.
Best I can recall, I built up a Ace transmitter from a Kit and constructed the digitrio 1 shots to modulate it. Now I'm thinkin it and the receiver with the decoder built in may (don't know for sure) have been in that or another box that was probably left on the loading dock-at this point who knows? I've been testing my memory trying to draw up the schematics of the trans encoder. Four one shots I think. This circuit works like a ring counter and I don't think this is what Ed Thompson drew up. I realized this tid bit of info after I BREADBORDED my circuit. The timings aren't what I remember anyway, so I am in need of help. Think Ed used snL7490's for the decoder. Mabey not. I never got to build the servo amps so I really need help on these circuits. Anyhow I can use all the help I can find.
I would appreciate your help more than you can imagine. Thank you very much for anything you can throw at me, Magone

jaymen

Here is a link to the Digitrio article, and some photos in color of one that was built way back when:
ftp://ftp.roguebay.com/Vintage%20Rad...gitrio%202.pdf

Jay.

magone

Hi there Ray and thanks much!
This link cleared up the dilema I was having with the timing problem.
Turns out I had forgoten the use of a unijunction oscillator to ensure correct operation (sequence) ie, getting the correct control stick to the correct channel. Therefore, no mix up of stick versus control channel. End result is it keeps the #1 decoder one shot in the receiver in step with the #1 Encoder one shot in the transmitter by generating a 4 or 5 millisecond pause in the serial stream at the end of the last control pulse called the sync pause pulse allowing all the one shots to reset (get ready for the next series of control pulses).
Anyhow, thanks again and keep them cards and letters comin'.

Signed,

The greatful George

jaymen

actually a flip flop works better than the unijunction pulser to run the encoder string of one shots. But, the real easy way to do this is to use a special IC developed by Signetics Semiconductor, the NE5045, it is an all in one encoder that has provisions for servo reversing, dual rate and exponential, all in a 16 pin DIP. Saves alot of time, works great, was used in all the Airtronics XL series transmitters, and the Ace Silver Seven.

magone

Hey Ray! Yea-I'll have to check it out. sounds like a cool IC. Exp too! real cool!

Magone

iflyj3

My Feedback: (7)

I have a Silver 7 encoder board that I have no use for and you are welcome to it. It does have a choke that someone let the smoke out of, but that is probably the only problem. BTW, the IC on it is a 5044. Send me an email or PM with your address.

magone

hey there iflyj3-what a great guy! Yeah, I'll take it. I think I can get it working. email is [email protected] Drop me a line.

regards magone.

pchristy

My apologies for this late addition to this thread! I stumbled across it by accident whilst looking for some information, and have some information that may assist others trying to renovate early systems.....

Back in 1967, I bought my first proportional outfit - a second hand Bonner Digimite 8, which I still own, and is in working order aside from needing new battery packs!

I bought the set off a fellow club member, who had had it from new, and it had performed flawlessly whilst he owned it. It also proved totally reliable to me as well.The fellow club member who sold it to me used to run a small model supply operation from a shed in his garden. I know this sounds very dodgy, but there were no local shops able to supply high quality equipment, and back it up with practical advice. Hugh fulfilled this role admirably, and always had "good stuff" in stock. Hugh had supplied one of the then new Digimite 4 sets to another club member, but unlike the 8, it proved unreliable and lacking in range. In the absence of a local service agent, Hugh - who was a University lecturer, and highly qualfied, agreed to have a look at it. The first thing he found was that - compared to the 8 - it had very low RF output. A quick tweak of the RF coils in the transmitter fixed this, and the power now matched that of the 8. The customer had lost confidence in it however, so Hugh refunded the money, and used the set himself, selling his 8 to me.

From this point on the 4 behaved perfectly, and I wonder how many instances of the "Digimite Dance" were down to poor alignment when these things left the factory!

In the mid-70s, I built my own flight pack to make use of the Digimite transmitter, and this is where things get interesting!

I used an RCM classic receiver, but had to design my own decoder. Why? Because the Digimite transmits TWO pulses per function, not one, as in modern systems! To decode 8 channels, I had to build a 16 channel decoder. I used two CMOS 8-bit shift registers to achieve this.

So what is so different about the Digimite pulse train?

The neutral pulse width is 1.7mS, but every alternate pulse is fixed. I can't remember the channel sequence off-hand, but suppose "aileron" is the first channel: waggling the aileron stick will make the first pulse increase (say) in length, and the second one DECREASE by the same amount. Putting this another way: All the "even" channels represent servo rotation in one sense and "odd" channels represent rotation in the opposite sense! To reverse a servo, simply move it forward or backward one channel, as appropriate!

The Digimite servo seemed to use both pulses. The servo was symmetrical with a linear output rack. Reversing was achieved by removing the servo, turning it 180 degrees and re-installing it!

The fact that you had to transmit twice as many pulses as a more modern systems explains the very low frame rate, and is probably as responsible for the relatively slow servo response as the "analogue" features of the servo amp. Certainly using ordinary servos with my home made receiver caused them to run slower than expected and to be a bit "buzzy" in transit. The pulse stretchers were clearly designed for a faster frame rate! I wonder how it would work with modern "digital" servos? Note to self: Must try that!!!

Since many of the other early digital systems (F&M, RCS) used Digimite servos, and also had low frame rates, I assume they used a similar system. However, I haven't had one in my hands to check this!

Nonetheless, the home made receiver set up proved totally reliable, and I even used it in a Kavan Jet Ranger and a Schluter Gazelle! If I've managed to get the photos loaded, you'll hopefully see a picture of a very young me in 1976 flying the Jet ranger with the Digimite!

The other picture (hopefully!) shows the JetRanger again along with my MicroMold Lark, which was controlled by a Sprengbrook 6 radio.

The Sprengbrook was designed by Doug Spreng during his brief sojourn in these sceptered isles, and sold by Harry Brooks. At the time it was rated as probably the most reliable British proportional ever made. Bearing in mind the "human element" comments made earlier in this thread, unconfirmed rumour had it at the time that he was in England to escape the unwanted attentions of an extremely litigous ex-wife.....!!!

If the Sprengbrook set had a weakness, it was in the use of SCS switches in the decoder. Although these were genarally reliable, they were extremely sensitive to cold, as I found out one winters day! The temprature dropped below freezing, and the helicopter that until that point had behaved perfectly, suddenly went berserk and wrecked itself before my eyes! It appears that some (but not all!) of the SCSs stopped working at low temperature! I went and bought about 20 of them (they were fairly cheap), and then went through both my receivers with a can of freezer spray, replacing SCSs until I ended up with two receivers that would work at any temperature I could stand flying in!

Happy days!

Finally, what would be a really useful resource would be if someone (RC Hall of Fame?) could put on line any service information still around for this early gear! I managed to find a set of schematics for the Digimite, but I believe that Bonner produced a really nice and very comprehensive service manual for these systems. Similar information for other systems would be extremely welcomed by those of us struggling to maintain these elderly sets!


Pete Christy

jaymen

Nice info on the Digimite 8. Unfortunately, all the literature that is on the RCHOF is scanned in at such a low resolution that 90% of it is unreadable. To Ed's credit, he is not very technical, so one must excuse him for omitting the critical(to us tech types) schematics and service info. He tend to focus on title pages of manuals, literature, and copies of magazine ads for dating purposes primarily.

The Digimite 4 used a more conventional encoder scheme, which will work with the newer receivers, I had one in for repair not too long ago, it just needed batteries and tuning.

It is interesting to note how alot of guys involved in designing the first generation digital proportional systems here in California all played musical chairs at first, and by the time the dust settled we were left with basically Kraft, and RS, everyone else had sold or gone out of business, or moved to a different state! This all transpired in one very short decade from about 1965 to 1975. The whole industry turned over, established names went under, and the Asian imports replaced them. This is a typical scenario: An initial boom created by new technology, but run by enthusiasts is overwhelmed by larger industrialist once the market grows.

pchristy

Yes, I know what you mean about musical chairs! We knew most of the names over on this side of the pond, but rarely got a chance to meet these guys!

By the late 60s a lot of the knowledge about digital proportional had trickled over here - helped enormously by the Digitrio and Classic articles in RCM, and for quite a while it seemed as if everybody and his dog was manufacturing gear in his garage! This was aided and abetted by the US move to 76 MHz, which caused major problems when the gear was modified back to 27 MHz for export to Europe. Because the antennae are so much more efficient at 76 MHz, manufacturers quickly discovered that they didn't need such beefy output stages to deliver adequate range. Unfortunately, this meant that sets designed for 76 MHz and modified to 27 MHz for export became rather flea powered devices. The reputation of American gear sank to rock bottom over here, after years of being the most desireable stuff around! I know in my area nobody would touch Kraft gear with a bargepole, because of its reputation for pitiful output on 27 MHz! Such a shame!

But all credit to Doug Spreng, who is generally credited with being the father of the pulse width servo system. That surely was a stroke of genius - a pure Eureka moment!

The early Japanese sets that arrived in the UK were also pretty awful initially! Most of the UK manufacturers looked down on them with disdain, and clearly forgot the lesson of the motorcycle industry! The Japanese learned fast, and weren't afraid of tooling up for real mass production. Our hand-made sets couldn't compete, and all our home grown manufacturers have long gone too.

I still use my "home-brew" 459 MHz set quite a lot. It is a frequency unique to the UK, so no commercial manufacturers are interested. It was made commercially for a while, and I still get the odd set back for overhaul, but the days of the "back yard" manufacturer of RC gear are now just a rosy memory!


Pete

redroadster

[hi phil, yes i used staveley analogue with the kraft sticks in my earlier days,i have just retired and have come back into the hobby,at the moment i am useing futaba 6ex 2.4ghz but i would like another stavely analogue! is yours possibley working and for sale?,please let me know.regards david [bradford west yorks]

RFJ

A silly question perhaps but what is the origin of the brand names Min-X, Citizenship, Glass City and Space Control.

Ray

iflyj3

My Feedback: (7)

The USA.....

jaymen

Citizen-ship was Vernon McNabb's name for his citizen band(27MHz) r/c radios. Space Control was coined in the mid 1950's duing the beginning of the space race by Hershel Toomin as the name of his analog proportional system produced by the Solidtronics division of Electrosolids. Min-X was the brainchild of Jack Lemon, who named the company Min-X radio corp. Glass City reflected the nick name given to the city where those radios were made, much like New Orleans is often called "the crescent city".

RFJ

Thank you Jaymen. So it's -

Citizenship - named after the citizens band
Space Control - named after the space race
Glass City - named after Toledo, Ohio
Min-X - ??????????????


Ray

saltracer

Great info. It brings back memories and I wish I had kept some of the old stuff. I was living in Albuquerque, Nm. in the 60's and my first system (other than escapements) was a F&M system I bought from Frank Hoover. I put it in a Tri Squire with a veco 19 and Frank test flew it for me.
I haven't gotten much better but the radios shure have.
Howard[8D]

jfuller

My Feedback: (8)

Hi,

Easy for me since I live in NM and F&M was made in Albuquerque.

CG equipment was named after Frank Hoover's son, CG Hoover. I knew CG but I never did know what the initials stood for.
The company's name changed to F&M around 1960. That stood for Frank & Molly.

James Fuller

tedbmoss

AS I remember it; Frank Hoover started CG Electronics, named after his son. Then he started F&M Electronics and made digital equipment. Ted White was his engineer. There was some problem with one of the companies after he sold it and he bought it back. CG Hoover and Ted White were hot pilots and used to do R/C combat together.