Pro-2026 battery backup

[sean_kd4adv]

I have a Pro-2026 "Patrolman" 100 CH Scanner.

How can I keep the frequencies in the scanner when I disconnect from the main power supply whether it be a cigarette lighter or a AC - DC power supply?

This has a 9-volt battery connector on the back and I would like to tap into somewhere on the board that has continuous 9-volts that will keep the frequencies from being lost when the scanner is disconnected from the main power source.

Has anyone tried this? What were your results?

Before I make an attempt, please respond with your ideas on this.

Tnx.

Sean

 

[CStarr59]

Sean, every scanner I have ever owned never lost the frequencies when they were unpluged or power was cut off. I had a sc150 in my closet with no power attached for 3 years and about a month ago I pulled it out and charged the battery up and it still retained the stored frequencies. Unless your scanner is very old it should retain it's memory for some time without power. You mentioned your scanner has a 9v attachment on the back, did you try putting a battery in there and see what happens?

 

[KC0QNB]

Use the battery think about it, when you unplug the radio there won't be any power on the board, some older scanners came with a battery backed memory, the technology for non-volatile memory wasn't as refined then as it is now. :wink:, If I unplug my PRO46 with no batteries in it after just a few days it will have no channels stored.

 

[RadMarv]

Found the line below in the Troubleshooting part of the online manual. I don’t exactly understand how a fuse would be a problem. Reading the manual the unit should retain its memory except for the “MONITOR MEMORY” channel.

"If the memory is lost, you might need to replace the orange continuous power wire’s fuse."

If the unit has a 9V battery holder it is most likely a battery backup for the memory as others have suggested. I would just not remove or replace the 9V battery without the unit being powered ON by the 12V battery system you are using. I just don’t see a mention of the 9V battery backup in the online manual.

http://support.radioshack.com/support_electronics/8438.htm

My brother just told me that the continous power wire is designed to continously feed power to the units circuit even when the unit is turned off. Similar to what many household TV's have to maintain their internal memory sich as the timers for turning them on at certain times and VCR's memory for timed recordings.

 

[DickH]

My brother just told me that the continous power wire is designed to continously feed power to the units circuit even when the unit is turned off.

Yes, that's when it is using a car's 12 volt power or if it's in the house you need to leave the power adapter turned on all the time.
I haven't used mine for a long time, but as I recall, the red wire goes to the 2026 ON-OFF switch. The orange wire supplies 12 volts directly to the memory backup, and does not go through the switch.
When running the 2026 in the house, I wanted to turn the 12 volts ON & OFF before it went into the radio so I had to add a 9-volt battery connected to the orange wire and kept it separate from the external 12 volts.

 

[slypx]

Sean, every scanner I have ever owned never lost the frequencies when they were unpluged or power was cut off. I had a sc150 in my closet with no power attached for 3 years and about a month ago I pulled it out and charged the battery up and it still retained the stored frequencies. Unless your scanner is very old it should retain it's memory for some time without power. You mentioned your scanner has a 9v attachment on the back, did you try putting a battery in there and see what happens?

Sorry but that's not quite true, it happenned to me with three scanners that I've put aside for 4 years (when I moved) and got them out less then a year ago and they were blank as new !

These scanners are from another generation and they are Pro-58, BC560XLT and Pro-2046 and none of them has a 9V connector. My Pro-2006 has one and a alert for "LowBatt" but not these.

Man ! Thinking about it, they look really "antique" compare to my 780, 996 and 396 !!!!!!!!

 

[sean_kd4adv]

Thanks for replies, I'll buy a 9-volt battery

Alrighty then, I will buy me a 9-Volt battery

Thanks for the info

Sean
KD4ADV
Grid Square : FM17ai
Amelia County, VA

 

[K7JKZ]

PRO-2026 Memory

My PRO-2026 lost memory after several days of no power. I opened up the unit in search of a battery that might need replacing. Instead, I found a 0.1 F 5.5 V capacitor. Now one-tenth of a Farad (0.1 F) is a lot of capacitance. That's equivalent to 10,000 uF, or 10,000,000,000 pF, to be silly. Apparently, and this is my assumption, this quite large capacitance is in the circuitry to hold the memory for a short, but not extended, period of time. The operative formula is T = RC, where T = time, R = resistance, and C = capacitance. The more the capacitance, the longer the time the circuit will remain charged, or to some percentage of charge. The amount of time this scanner will hold memory is plenty enough to get from one power source to another, but not over several nights.

 

[2manytoyz1]

Mine had the 9V external battery clip. I've since put the 9V battery inside the scanner case. It works great. This scanner had been in storage for years, and still retained the programming. I also have John Montalbano's PROgramit interface installed, allowing me to reprogram the radio via the computer. Great little scanner.