[wxsig] T238+, X1W-1. X1W-2 and AAG, crossed over

[John Bennett]

I had to cut the trace on my AAG-v3 to make it work with the original
T238. Have not had any problems, so would assume it's not really
required. Only have about a 75' run, however.

jb
n4xi

On Sun, 2007-07-08 at 13:28 -0500, John Koster wrote:
> On Sun, 8 Jul 2007, Rasputin Novgorod wrote:
> 
> > > A little history, as I remember it,   Seems like the 3rd rev of the
> > > AAG WX 
> > > STN came out while the T238+ was in the final stages of going into
> > > kit 
> > > production, so there wasn't much chance of modifying it.  John was
> > > still 
> > > working with alpha versions of his two boards, so he hedged his bet
> > > and 
> > > put the jumper options.  No one has ever come up with an explantion
> > > as to 
> > > why AAG decided to be different.  
> > > 
> > > What can be done?
> > 
> > The British still drive on the wrong side of the road.
> 
> But it makes for fun when you visit the carribean islands and rent a car.
> 
> > 
> > First I made a custom cable for the AAG. Got in trouble
> > a month later swapping cables around, and forgetting that. 
> > So I cut the traces on my AAG and modified it to conform to
> > the rest of the T238+, X1W-1. X1W-2 world.
> > 
> > You know, it always annoyed me, that instead of using a
> > standard telephone cord available anywhere, to interconnect,
> > we have to snip off and replace the plug at on end, with
> > crossed over wires.
> > 
> 
> It is a pain, but then there appears to be both types on the market place.  
> I have a box full of cables in the garage and I find both types.  The
> telco's a long time ago figured out that they needed to make the new
> electronic phones polarity independent just like the old rotary dial
> phones to avoid reversed polarity problems.  If you had 6 jacks in your
> house, you could garantee one of them was reversed.
> 
> I've always been annoyed that the telephone connector has become a catch 
> all for some many applications.  
> 
> I don't know why Dallas chose to use the RJ11 on their WX Station.  I've
> worked for companies that used 1-wire devices, and there's not one RJ11 in
> the circuit to the devices.  We also determined that CAT5 wasn't best
> choice for getting the longest reliable runs.  However we were looking for
> 300 or more foot runs (to a single iButton).
> 
> How difficult are the trace cuts in the AAG unit?  Does the AAG require +5
> to operate or can it still be powered from the data line the way the
> original Dallas WX Station?  Is the AAG unit the only one 'backwards'?
> 
> If the AGG unit doesn't require +5, and it's the only one that needs 
> modification, then it would make sense to cut on it.  It shouldn't be too 
> hard to isolate pins 1 and 4, but I'd have to see the actual PCB layout to 
> be sure.  If there's a GND plane around pin 4 it might be difficult unless 
> there's the little heat relief traces between the actual pad and GND 
> copper (like 4 spokes on a wheel). 
> 
> Of course there's the problem of voiding the AAG warranty by cutting 
> traces. 
> 
-- 
John Bennett
Evansville, IN
Amateur Radio Web: http://n4xi.home.insightbb.com
Where am I? http://www.findu.com/cgi-bin/find.cgi?N4XI
Bike Racing Images: http://n4xi.smugmug.com/
Live Strong - Lance Armstrong Foundation: http://www.laf.org/