# Upgraded Digital Proportional TX20 now available



## TonyWalsham (Jan 2, 2008)

The Deltang TX20 has been upgraded.










Easy one handed operation.










Separate 9 volt battery compartment.










It is a bit bigger than the original version but will still fit in trouser pockets. A belt clip will be available soon.


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## Pete Thornton (Jan 2, 2008)

Tony, 

I'd still like to know what the functions do if you connect servos to the RX instead of an ESC. 

Clearly the throttle knob does what a stick will do - toggles the servo output from 0 -> max ? How does the direction control toggle work ?


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## TonyWalsham (Jan 2, 2008)

Hi Pete. 
The spring loaded centre off direction switch is that way specifically for operating my RCS ESC's. It sends a momentary full servo throw to set the direction. 
So, sorry to say this version is not really suitable for controlling 2 x servo live steam locos. Yet. 
It can of course be used as is with the speed control for driving with the Johnson bar only. 
It would be a simple matter for me to replace the spring loaded toggle with a regular SPDT centre off switch for 2 x servo control. However, that would only allow full travel of the Johnson bar from the centre either way. Adjustment would need to be with the linkages, not in software. 

I am sure Deltang is open to suggestions for a variation of the design to make it suitable for basic live steam. I was thinking along the lines of another trim pot to accurately set the Johnson bar servo.


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## Pete Thornton (Jan 2, 2008)

Tony - thanks. I would certainly like a version that runs my live steamers!


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## Garratt (Sep 15, 2012)

Tony, I know the more sophisticated live steamers have a fully adjustable Johnson bar/valve control but on the simpler versions of live steam engines the Johnson bar is just set for direction and variable speed via servo on the steam regulator. Can this system be used for that with your modification?


I think the new larger control case may have better ergonomics in the hand. More like a TV remote. Chunky small boxes can be a bit awkward.

Andrew


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## TonyWalsham (Jan 2, 2008)

Hi Andrew. 
The spring loaded direction change switch on this TX20 works just like the spring loaded stick on a regular stick radio. My operating program requires that the direction change stroke be returned to neutral before taking effect. You could use the TX20 as is but you would have to hold that direction change switch over (and get full servo travel) whilst running. 
As I explained to Pete, I could fit a non spring loaded centre off SPDT which would give you full servo travel in either direction but you would not have to hold the switch whilst running. 
Although it would have been easily possible to change my operating program, I wanted to make this TX backwardly compatible with earlier RCS Digital proportional ESC's. 
To avoid possible confusion with this one, I think it would be better that a TX with a variable setting for the Johnson bar via another knob (also with a centre off detente) be developed, that looks and operates differently from this one. 
I would appreciate input from interested live steamers before I jump into the deep end. 

Actually, the main reason for going with a bigger palm sized case was to make the battery more accessible when battery replacement was needed. Plus, I could put the other function buttons on the front making assembly easier.


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