Pro-197 Wall Wart Question

[tglendye]

I cannot find my original AC adapter for my Pro-197. I have a RS wall wart that is 12V, 1 amp and the T-connector with it. From what I have been reading the voltage should be between 12-13.8v. How about the amps... I think I read where it should be 600 MA, but will 1 amp do?

Also, does anyone know or how do I determine if the tip polarity is =+ or - ?

Thanks!

[n5ims]

With external power supplies (such as your "wall wart") what is important is the type of voltage supplied (AC or DC) and value of that voltage (e.g. 12v) must match what the device (your scanner in this case) requires. The "amps" value must be at least what is required but may be more. Amps are pulled by the device as necessary so as long as your supply will handle what is being pulled you're good. When this value is exceeded is when you'll have issues.

For example, my scanner, like yours, is a Pro-97 but since I have a large power supply for all of my radios, I use it instead of the "wall wart". I replaced the 12v, 600 MA wall wart with a 12v, 20A power supply. This supply can supply nearly 40 times the number of amps that the old "wall wart" does without issues. Now if that power supply was only a few volts off of the 12v value there would be smoke from the scanner, but all of those extra amps are just fine.

[RDGDigital]

From the PRO-197 user's Guide:
( http://www.radioshack.com/graphics/u...0197_PM_EN.pdf )

Powering Your Scanner
You can power your scanner from a wall outlet, or from your vehicle’s
battery.

You must use a power source that supplies 12V DC and delivers at
least 600 mA. Its center tip must be set to positive and its plug must
fit the scanner’s DC 13.8V jack. The supplied AC adapter and DC
power cord meet these specifications. Using a power source that
does not meet these specifications could damage the scanner or the
adapter.

[DickH]

Sorry to change the subject, but with an expensive digital scanner you should consider what many of us here advocate.
Do not run your scanner with an A/C adapter.
You could have a component failure or a voltage surge or a lightning strike that could ruin the scanner. I have had it happen as have many others here.
Just buy an extra set or two of batteries and a charger.

[gewecke]

Originally Posted by DickH

Sorry to change the subject, but with an expensive digital scanner you should consider what many of us here advocate.
Do not run your scanner with an A/C adapter.
You could have a component failure or a voltage surge or a lightning strike that could ruin the scanner. I have had it happen as have many others here.
Just buy an extra set or two of batteries and a charger.

True with a pro-106!
But since it's a pro-197 the op mentions, I would suggest a regulated power supply. Preferably one of the switching variety, rather that the supplied wall wart!

73,
n9zas

[DickH]

Originally Posted by gewecke

True with a pro-106!
But since it's a pro-197 the op mentions, I would suggest a regulated power supply. Preferably one of the switching variety, rather that the supplied wall wart!

73,
n9zas

I had a regulated power supply - not a wall wart - running my PRO-95 when a resistor in the power regulator circuit burned up, probably from a shorted diode or capacitor. Fortunately it did no other damage so I just ran it on batteries after that.

[RadioDaze]

Originally Posted by DickH

I had a regulated power supply - not a wall wart - running my PRO-95 when a resistor in the power regulator circuit burned up, probably from a shorted diode or capacitor. Fortunately it did no other damage so I just ran it on batteries after that.

The point gewecke was making is that the Pro-197 is NOT a handheld radio, it's a desktop radio. It doesn't take batteries.

That being said, it's often a good idea to use an AC surge protector to plug the power supply into.

[DickH]

Originally Posted by RadioDaze

The point gewecke was making is that the Pro-197 is NOT a handheld radio, it's a desktop radio. It doesn't take batteries.

That being said, it's often a good idea to use an AC surge protector to plug the power supply into.

... The point gewecke was making is that the Pro-197 is NOT a handheld radio, it's a desktop radio. ...
It would have been helpful if he had said that.

[KA9AHQ]

I am about 2 weeks away from an upgrade to a pro-197
Happy Happy Joy Joy

I will power it via the DC cable connected to a small motorcycle battery and will have a float charger also connected to the battery.
The battery is my ups and filters any crud that makes it through the charger.
The battery acts like (and is) a giant capacitor.

Motorcycle or equiv because they are sealed(read not messy)
Float Charger I got mine at Harbor Freight for about 6 bucks.
I hope this helps
Ed

[chrislxq]

I couldn't get any adapter from Radio Shack with the proper 600mA, and 13.8VDC. I contacted Scanner Master to find a GRE Wall Wart. The GRE works well.

[KC2OBW]

Originally Posted by DickH

... The point gewecke was making is that the Pro-197 is NOT a handheld radio, it's a desktop radio. ...
It would have been helpful if he had said that.

Really?? Not for nothing if I'm reading a post about a radio I never heard of and seen before I do a quick google search the radio in question or whatever the item might be. Its not gewecke's fault you didn't know what a pro197 was...

[KC2OBW]

Originally Posted by KA9AHQ

I am about 2 weeks away from an upgrade to a pro-197
Happy Happy Joy Joy

I will power it via the DC cable connected to a small motorcycle battery and will have a float charger also connected to the battery.
The battery is my ups and filters any crud that makes it through the charger.
The battery acts like (and is) a giant capacitor.

Motorcycle or equiv because they are sealed(read not messy)
Float Charger I got mine at Harbor Freight for about 6 bucks.
I hope this helps
Ed

Good Luck with it!! I've had my 197 for a little over a year now and its a awesome scanner!! You will be pleased with the audio on both analog and digital!

[WJYSTV62]

The Pro-197 has two internal voltage regulators. The original wall-wart has no regulation in it all. I've not opened it but the output floats and changes with load so I suspect there's nothing in there. Most will provide about 16V with the scanner connected and running and 20V with no load. Even though it says right on it 13.8V it is never even close to that.
You'd need something at least about 10V to insure the highest voltage internal regulator (8V) turns on and enough current to power the unit fully, so at least about 500mA. Having a supply of too much current is a waste and could cause serious problems if a fault occurs. Say something fails in the radio. Instead of 600mA burning one component open you have a 3A supply connected and it destroys the whole radio. Sending it in for repair is no longer an option. I would not exceed about 24V because this would be above the maximum the internal regulators can handle. So, look for something between 12 and 18V and from 500mA to 1A. It need not be regulated. I would advise against a switching type supply. There's a reason why the original one is a linear supply even though switching types are readily available and cheaper. Switching supplies generate outrageous quantities of radio emissions unless extra care is taken to eliminate them. This will cause loads of interference on your sensitive scanner. Cheap supplies are generally worse. Linear supplies are becoming very difficult to find. Pretty much if you want a linear supply you have to build your own.
The worst part is the connector. The 197 uses an EIAJ-5 connector. Radio Shack does not sell this connector. Good luck finding anything with that connector on it. Since it is intended for higher voltage and current than most coaxial power connectors something like an old notebook computer power supply might be just the thing. Although it's a switching supply they are usually well made and quiet and may even have the proper connector.
PP-016 CUI Inc | CP-026-ND | DigiKey
(they have a minimum order)
http://www.allelectronics.com/make-a...-SUPPLY/1.html
(also a switcher and not the proper connector but it's an idea)