TX history of frequencies and modes

[Mike Blandford]

I started by building a Tx from a Remcon kit (while at university, I couldn't afford a ready made system). I got a different make of kit receiver (with lots of "delicate SCRs), bought some Sprengbrook servo mechanics and made servo amplifiers for them. I put that lot into a home designed and built 'plane and went flying! That was interesting as I wanted to use mode 2, and everyone a Beaulieu was mode 1. I got the 'plane in the air and kept it there (overcontrolling!), but one of the mode 1 pilots having seen it flew helped trim it out and got it straight and level, then I was OK. (I was a qualified (full size) glider pilot and had 30 hours in a Cessna 150 as well so I knew how to fly).
Really satisfying to have built all the radio gear and designed the 'plane as well.

Later I got the book above and built a Rx to give me a second Rx. I also replaces the SCRs in the first Rx with a 74L shift register and repeated that for the Microtrol Rx so I had 7 channels on both.

I also rebuilt my servo amplifiers with 11 transistors instead of the normal 9. This give a much better drive to the servo motor.

Having obtained the circuit diagram of the Sprengbrook Tx, I then built a custom Tx using that. I then got "distracted" by building my own computer (before you could buy one).

After years away from the hobby, I returned needing 35MHz equipment so bought a Fleet Tx and built a couple of Micron receivers. I rebuilt my servo amplifiers using some NE543 ICs, and some ZN409s and restarted flying.

I no longer need to buiild everything, so I write the firmware for computer Txs (er9x and erskyTx, which many prefer to openTx as it is easier to use), and some parts of the firmware in other RC things like the MPM module and the openXsensor.

The book certainly helped with understanding how everything should work. Unfortunately, my copy disappeared at some point, I may have lent it out and never got it back.

Mike

Edited By Mike Blandford on 11/12/2020 23:19:08

[Bob Cotsford]

Posted by Gary Morton on 11/12/2020 20:12:51:

I must see if I still have those on the bookshelf upstairs, a bit of nostalgic reading

[Phil Green]

Hi Paul, as a young teenager I too was inspired by your book, at school the prizes were book tokens and I chose the first edition of "theory and practise" from which I learned an awful lot. I 'borrowed' a lot of your ideas for my home-brews, most of which are still working - so a sincere 50-years-late thank you from me!

 

 

Edited By Phil Green on 12/12/2020 11:35:31

[Andy Stephenson]

I had a Radio Modeller book in the 70's which showed various constructions and circuitry for analogue/GG control which I experimented with but there were some dreadful mistakes, misprints and some downright misleading info in it. I can't remember who wrote it but there was a footnote which said that the author was not able to enter into any discussion about the contents. It was obviously not proof read by anyone with technical competence.

I gave up trying to construct my own gear from scratch and on the advice of the local model shop I built an HB kit radio.

A.

[Paul Newell 2]

Andy,

Not guilty! But do know of the book to which you refer.

Phil,

Thanks for the thanks. It is only in later years that the significance of the books became apparent.

[Mike Microtrol]

Paul

Though its some while since the last post in this thread I just wanted to add a note about my experience. Paul I made up your Microtrol R/C system from your 1972 book and it worked very well. I actually made up two TXs and could linked them up with a buddy box lead. I got most of the parts from D.J. & D. Modelgear in Garforth Leeds and Model & Control Specialists in Sunderland. To set the timings I had a Russian oscilloscope which in the 1970s were being sold rather cheaply. I had a R/C boat, a Sea Urchin powered by a Mills 0.75 with water cooled head and exhaust pipes fitted by the factory. I was a member of the Bradford Radio Aero Modellers Club for several years and built from plans as well as from kits, several of them David Boddington designs.

Then at the end of 1979 I stopped model flying, I felt the hobby was taking me away from being with the family. I did buy your 1981 book which featured your 35MHz FM system. The popularity of CB radio meant then that continuing to fly using 27MHz seemed too risky for me. I still have a couple of my boats, my old planes, R/C equipment and many engines some of which I recently sold but the stuff all needs to go before it becomes someone else's responsibility to clear out.

 

Reading your post on herePaul has brought me some closure concerning home built R/C equipment and the current availability of modern high tech R/C equipment.

Thanks Paul for your inspiration and help, I had some enjoyable times flying my R/C models.

Mike