Going WAY back about a Realistic Pro-2026

[bep]

Got out and dusted off an old Pro-2026. Small and perfect for my mobile install. The only drawback is that it MUST maintain power to retain programming. There are three wires (gnd., constant 12V, and ignition 12V)

The manual states under initializing/resetting "....it might stop operating if the batteries become too low....."

I have looked inside and cannot see a battery, however there are some hidden covered spots. I was hoping someone may tell me if there is a battery prior to my digging further.

Sure wish I remembered when I got this unit.

Thanks

 

[DickH]

Got out and dusted off an old Pro-2026. Small and perfect for my mobile install. The only drawback is that it MUST maintain power to retain programming. There are three wires (gnd., constant 12V, and ignition 12V)

The manual states under initializing/resetting "....it might stop operating if the batteries become too low....."

I have looked inside and cannot see a battery, however there are some hidden covered spots. I was hoping someone may tell me if there is a battery prior to my digging further.

Some manuals have errors and I think this is one. As long as you keep 12 volts on the orange wire you won't have any problems. My guess is the word "batteries" was supposed to be "battery", meaning your car battery.

 

[bep]

I thought of this, and hoping I was wrong and there would be an internal battery. 100 channels to program every time there is a power glitch, no I do not think so.

 

[scansalot52]

Thre are a couple of ways to get around the power glitches that may be worth trying. I would suggest trying these before you program all 100 channels.

The first is to place a diode inline between the orange wire and the 12v source. This might prevent just enough power drain to keep the scanner programmed. Use one rated at an amp or wire what you can get in parallel to equal an amp rating.

The second step might be to place a dpst or dpdt relay on the orange wire and wire it so that 12v from the car normally feeds the orange wire. Wire a 9v lithium battery to the other side so that if 12v fails, the 9v would hopefully supply enough voltage and amps to hold the programming for awhile. You don't want 12v flowing into the 9v. The relay might not switch over fast enough with out also using diodes.

I think I remember using the diode fix on an old RS 12v digital clock that liked to reset when I started the car. I don't recall every trying the second.
I have a Uniden 760 mobile scanner that had a holder for 2aa built into it instead of the orange wire. You might find a schematic somewhere and try to duplicate that circuit as a 3rd idea.

 

[scansalot52]

I have looked for the circuit that I suggested and can't seem to find it on the internet. Also, the items were to be connected to the constant wire. I can't remember which color wire that is on that scanner.
Perhaps someone will post the values of the components plus how to connect them.
Didn't want to bump this but I could not edit prior post due to it being here for a couple of days.