Usb-UIRT 5v to Xantech 12V

[FrankMc]

Hi Smarty

fter looking at the (very limited) installation page, I guess I would wire signal to signal, ground to ground, and "posative voltage" to the 12V Xantech blaster connector.

I would then run the power source (12VDC) across the ground and +12V connectors. Right?

I would say thats correct from a quick glance at the doc ...maybe some xantech users can confirm....

I think the resistor mod i mentioned will do the trick ., although as you say its good to have a plan B ;-)

Good Luck
Frank

 

[FrankMc]

Hi Guys

Came across this info while browsing the USB UIRT Forum....This was a reply from Jon Rhees to a query.......
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The jack on the back has two channels of output. They are common-ground (jack barrel), and use a PNP transistor (collector) connected to the output through an 82-ohm resistor. Thus, the output, when active drivers to approx. 4.7 volts.
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HTH
Frank

 

[jryan15]

fyi - i had trouble interfacing my usb-uirt with my xantech system. i found on another site that i could use a diode to block backfeed from my xantech system into my usb uirt. i have in/out ir working great between the usb-uir and the xantech without using any amplifiers, just a diode between the usb-uirt output and the xantech input... for more info, see my post on the usb-uirt forums below.

post at usb-uirt forums

 

[Smarty]

Thanks for your input jryan15

Sounds like you are saying that maybe I should just try the diode (anti-backfeed) approach first before looking into amplification.



Bear with me, I'm a NOT an EE......
I understand that a diode is essentially an "one way" type device. It is this "one way" ability is what keeps the 5V UIRT system from loading down the 12V Xantech sytem (Ok - I understand this part).

BUT, what effect does the "one way" diode have on INCOMING signals to the different zones available via the stereo jack on the back of the usb-uirt? Does the adding of the diode convert the send/recieve ability of the stereo jack to send ONLY?

 

[Guy Lavoie]

That's because the Xantech system seems to "mix" its various input sources by connecting them literally together. I do know that that's how the Buffalo connecting blocks work. In other words the connecting block is designed for signal sources that are high impedance outputs unless it is driving itself. This means that if an input source is getting a signal, the other sources will allow their output lines to be pulled up to 12v by the active input. The problem with a 5 volt signal source is that it might not allow its ouput to be pulled up over 5 volts. This causes the other input sources to get clamped down to a maximum of 5 volts and the connecting block appears to put out weak signals. I first came across this on the Applied Digital forum from a member who was trying to mix an Ocelot output with other inputs to an Xantech conneting block. I ended up suggesting to add a signal diode (anode to Ocelot, cathode to connecting block input) so that the Ocelot could pull up the signal line when it was driving, and not load down the other input sources to the connecting block when they were driving (the diode becomes reverse biased).