Radio Shack AC Adapter Question

[ronmicha]

I've lost my AC Adapter to my Radio Shack scanner which called for a 13.8V w/ 500mah. I've got another Radio Shack adapter which is a 12V w/ 500mah. Can I use this without blowing up the radio? Seems I recall that as long as the voltage is lower it's okay; but if it's higher you're in danger of harming the radio.
Thanks.
Ron

 

[Shackman]

I've lost my AC Adapter to my Radio Shack scanner which called for a 13.8V w/ 500mah. I've got another Radio Shack adapter which is a 12V w/ 500mah. Can I use this without blowing up the radio? Seems I recall that as long as the voltage is lower it's okay; but if it's higher you're in danger of harming the radio.
Thanks.
Ron

Just make sure the polarity is right with the new adaptor and you will be fine. Your old one was probably a positive tip polarity and some adaptors can be set either negative or positive tip. You do not want to get that the wrong way.

 

[gmclam]

I've got one of those "universal adapters" here. It has 9 different plugs on it and two switches. One switch is for polarity and the other for voltage. The voltage selections are 3.0, 4.5, 6.0, 7.5, 9.0, 12.0 volts. The PRO-92 & PRO-95 scanners both call for 9v at 300ma. This universal unit provides 500ma.

What I found is that the voltage settings are only accurate under FULL load. If I am drawing less than oh 250ma from the supply, the voltage is quite a bit higher. I opened the unit up and the filter capacitor is a pathetic value. So there is also quite a bit of ripple on the ouput. They are depending on the device or its batteries to filter the power further.

I eventually acquired a better supply. But if I did want to use this universal model, selecting the voltage to 7.5 gave me a little more than 9 volts under the load of either of my scanners.