# AirWire /G-Wire External Selector Switch / Remote Address Switch??



## acmartina (Jan 6, 2008)

Hi,
I am looking for a way to change Airwire / G-wire RX frequency without opening up the locomotive. I recall a number of years ago seeing some photos of a three-dip-switch setup installed on the exterior of a locomotive. The Airwire decoder manual refers to an "External Selector Switch". The G-Wire website refers to a "Remote Address Switch". Both have three terminals that would account for a 3-dip-switch arrangement. But I don't seem to find anything like this listed for sale by either CVP or QSI. 

Any ideas where I might find such a thing? Thanks.

Steve
Cypress, TX


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## Greg Elmassian (Jan 3, 2008)

you can buy a 3 position dip switch, or another rotary switch from digikey or mouser (and possibly all electronics). 

Be careful when unsoldering the other switch (I believe you have to )... you can use any 3 single pole, single throw switches... the dip switch and rotary switch are just for compactness. The rotary makes it easier than figuring out the binary for 0 through 7 (or do they number it 1-8? Too lazy to look it up right now). 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

A three way DIP switch would require four connections. 
One for each contact and one for the common.


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## K27_463 (Jan 2, 2008)

I have the rotary switches that are on the QSI and Airwire b0oards in stock... 

Jonathan/EMw


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## Bill Swindell (Jan 2, 2008)

You do not have to remove the existing switch at all. There are 4 terminals on the AirWire board to allow the connection of an external switch. I use an 8 position rotary switch that looks like the ones on the AirWire receiver board for my conversions. You just need to leave the onboard rotary switch at 0 so the external switche(s) can control the frequency.


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## acmartina (Jan 6, 2008)

Thanks all! Thats great. I had a look at the Mouser and Newark sites and found a whole slew of options. 
http://www.newark.com/grayhill/94hbb08t/dip-switch/dp/63K8764

Most seem to have six pins rather than four, but I see from the data sheets that the pins are labeled 1, 2, 4, 8, C, C. The G-Wire diagram shows it uses 1, 2, 4, C, so I reckon the 8 pin is not used and the C's are redundant (presumably Common)? Does that make sense?

Also found an interesting thumbwheel version at All Electronics that looks like it might be very easy to install on Aristo locos on the top switch panel. I may give it a try.
http://www.allelectronics.com/make-a-store/item/RS-143/BCD-PUSHBUTTON-ROTARY-SWITCH/-/1.html 

Steve


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## Bill Swindell (Jan 2, 2008)

If it has 1, 2, 4 & 8, That switch will go from 0 to 15. You can't use above 7. I would look for a switch that has 6 pins and goes from 0 to 7 since that is a match for what is on the AirWire board.


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## Greg Elmassian (Jan 3, 2008)

Just don't wire up the 4th switch? 

Regards, Greg


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## Paul Burch (Jan 2, 2008)

Jonathan at Electric Model Works has the exact one you need. See his post.


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## acmartina (Jan 6, 2008)

Thanks all. I will contact Jonathon offline. Sounds like the easy solution.

The big suppliers (Mouser, Digi-key, Newark) obviously carry everything you could possibly need, but being a bit of a novice, I always get a headache looking for something there! AllElectronics is more my speed! But just to close the loop on this thread, I went back and looked again at the datasheet that showed the 1,2,4,8 pins (here) looks like it was for a series of switches in the same 6-pin package but some having 8, 10 or 16 settings. So I presume for the 8 position switch, the no. 8 pin must be un-used. In any case, I did eventually find some 8 position switches that have only 4 pins (here). Headache starting up again ...

In any case, I appreciate the good advice. Thanks!

Steve


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## Paul Burch (Jan 2, 2008)

I did a couple LGB Mikados several years ago and just used three simple slide switches mounted side by side behind the smoke box cover. The outputs are just simple binary. One side of the switches are wired common. The other three leads are the frequency selector out puts,one wired to each switch. Switch 1 would be labeled 1,switch 2 would be labeled 2,switch 3 would be labeld 4. The outputs are just added together for a particular frequency. 
Freq 0,all off
freq 1,1 on
freq 2,2 on
freq 3,1 & 2 on
freq 4, 4 on
freq 5,1 & 4 on
freq 6,2 & 4 on
freq 7, 1,2 & 4 on

That should put some confusion in the mix.


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## Greg Elmassian (Jan 3, 2008)

Simple binary math 

the digits in binary are not "Worth" the same as in decimal.. 

with 3 digits... the rightmost is 1, the next one is 2, the next one is 4 

101 is 4 + 1 = 5 
111 is 4 + 2 + 1 = 7 
001 is 1 


000 0 
001 1 
010 2 
011 3 (2 + 1) 
100 4 
101 5 (4 + 1) 
110 6 (4 + 2) 
111 7 (4 + 2 + 1) 

so each switch can be a 0 or a 1 (0 = off, 1 = on, or grounded to common) 

Regards, Greg


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## acmartina (Jan 6, 2008)

@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css); Well it took me a year and a half from when I posted this but I did actually implement this today (successfully!) so I thought I would share the solution for posterity.

I bought a bunch of these 8 position, push-button switches, from All Electronics (http://www.allelectronics.com/make-a-store/item/RS-143/BCD-PUSHBUTTON-ROTARY-SWITCH/1.html).









To keep the installation simple, rather than solder the leads directly to the AirWire board (and therefore having to install the switch in the locomotive first), I use a four-pin connector with a board-mount header, also from All Electronics. Turns out it fits the AirWire hole spacing exactly. Here is the connector (http://www.allelectronics.com/make-a-store/item/CON-244/4-PIN-CONNECTOR-W/HEADER-0.10/1.html).









If you install the header with the open side facing the edge of the board, the red lead lines up with the common on the board and on the switch. Soldering to the board was extremely simple, as were simple solder splices in the leads. So now I can simply change the AirWire frequency with just a push of a button (no need to translate dip-switch binary). And no complicated soldering.

Hope this is useful for someone! Thanks.

Steve


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## Paul Burch (Jan 2, 2008)

Steve,
Good find. I have used several of the rotary type in the past which do require some soldering expertise. The specs give height and width. How much depth do you need for clearance? These will work fine on the Airwire decoders up through the G2's that have frequencies 0-7. I wonder if they have one that will work for frequencies 0-15?


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## acmartina (Jan 6, 2008)

Paul,

I will measure one when I get a chance (most likely Friday), but I would guess something between 3/4" and 1".
I did not see a 16 position version in All Electronics catalog but I am guessing Newmark or Mouser might.

On the bad news side, I had a quick look at the QSI G-wire board. It only has soldering pads - no mounting holes. On the weekend I will look closer. Maybe I can just drill them out. I did not measure the spacing. I have five of these that I would like to add switches to so I may need a different solution.

Thanks,
Steve


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## SteveC (Jan 2, 2008)

Steve

Just a FYI, they do make surface-mount type headers (i.e. no drilling needed), while the example may not be the exact one you're looking for but they do rxist...

Digi-Key - PN-WM1342-ND - Mfg. Molex - Molex PN-15-91-2045 - 4-pin, 0.1" (2.54mm) pitch, 90° SMT Header[/b]

Product Data Sheet[/b]


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## acmartina (Jan 6, 2008)

Thanks Steve. I will look into it when I get ready for the next QSI conversion. Eventually I need to retrofit four Aristo QSI installs.

Paul - I measured the switch I used today. It is about 13/16" deep from the bottom of the face-plate (i.e. how far it would protrude from the top of the surface it was mounted on). That includes a little piece of PCB on the base where the wires are soldered.

Thanks,
Steve 
@import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


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## Paul Burch (Jan 2, 2008)

Thanks Steve.


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## acmartina (Jan 6, 2008)

Hi,
Another update - I have successfully installed the same push-button switch with a G-wire receiver. I followed Steve C's advice and bought a handful of these Molex surface mount connectors -

http://search.digikey.com/us/en/products/15-91-2045/WM1342-ND/531449



It is not entirely compatible with the All Electronics cable. The pin spacing is correct but the form factor for the plug and socket are different. This was easily resolved with an Exacto knife, however. Several modifications are needed -
[*]The widths match but the plug is too tall. Remove top cover of the socket, leaving the sides and end [*]The socket has a do-da on the bottom to snap into a hole in a PCB. No place for that here. Slice ... [*]The plug has an alignment ridge on the bottom. That's gotta go too. [/list] From there, it is a good snug fit.


The nice part about the G-wire board (compared to the AirWire) is the pins are clearly labeled 4, 2, 1, C (as are those on the push-button switch) so it was easy to insure the correct alignment. With the Airwire, you have to study the manual a bit and test it first.


Here is a photo of my first retrofit with G-wire on a Dash 9 showing the push-button switch installed in the top panel just forward of the smoke unit before re-installing the G-wire (just forward of the opening, velcro'd to the wall inside the loco). I give Aristocraft credit for making the Dash 9 so easy to work with. Next up, four more older Aristo loco's that are not so easy!

I am excited this has worked out. I appreciate the advice. I look forward to easier mixing and matching with multiple trains and double headers!

Thanks,
Steve


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