Voltage; 13.8VDC vs. 12VDC?

[MacombMonitor]

The manual for the Uniden BC796D indicates that it operates on 13.8VDC. I realize it is rated for that voltage, because the charging voltage in the average vehicle is very close to that. If you were to operate the radio at 12VDC, from a large Gel-Cel, would there be any difference in performance, either RF, or audio level? Or does the radio have a voltage regulator that drops the 13.8VDC to 12VDC regardless?

Thanks!

 

[N_Jay]

The manual for the Uniden BC796D indicates that it operates on 13.8VDC. I realize it is rated for that voltage, because the charging voltage in the average vehicle is very close to that. If you were to operate the radio at 12VDC, from a large Gel-Cel, would there be any difference in performance, either RF, or audio level? Or does the radio have a voltage regulator that drops the 13.8VDC to 12VDC regardless?

Thanks!

MOst equipment speced for 13.8 runs from 11.5 to 15.

 

[seamusg]

The manual for the Uniden BC796D indicates that it operates on 13.8VDC. I realize it is rated for that voltage, because the charging voltage in the average vehicle is very close to that. If you were to operate the radio at 12VDC, from a large Gel-Cel, would there be any difference in performance, either RF, or audio level? Or does the radio have a voltage regulator that drops the 13.8VDC to 12VDC regardless?

Thanks!

You must use a power source that supplies 13.8 V DC and delivers at least
700 mA. Your standard 12 V car battery should be sufficient. The cord
connector’s center tip must be set to positive and its plug must fit the scanner’s
DC 13.8 V jack. The supplied DC power cord meets these specifications. Using a
power cord that does not meet these specifications could damage the scanner or
the adapter.
Per the manual you should be ok.

 

[DaveH]

12v or even a bit below instead of 13.8v should be fine. It's only two-way radios with high-power outputs that might put out less with lower voltage, but these usually regulate the TX voltage anyway (down to +11v typ.) for stable output.

I've tried running some 12v scanners on a small *regulated* switching-type wall-plug converter. Its output is stable just above 12v (12.4 typ.). Works fine, there is no AC hum (good when using headphones), and the adaptor weighs 2-1/2 oz versus about 1 lb. for the original.

Dave

 

[wesm1957]

The manual for the Uniden BC796D indicates that it operates on 13.8VDC. I realize it is rated for that voltage, because the charging voltage in the average vehicle is very close to that. If you were to operate the radio at 12VDC, from a large Gel-Cel, would there be any difference in performance, either RF, or audio level? Or does the radio have a voltage regulator that drops the 13.8VDC to 12VDC regardless?

Thanks!

I have a couple 12v gel-cells that I use for many things from powering battery chargers form my li-poly rechargable batteries to powering the two radar units I have. They are rated at 7 amp hours. I got them at the local hobby store I work part time at. We use them to power starter motors used to start radio control airplane engines. They are actually sealed lead acid batteries. I also have a couple that are rated at 1.2 amp hours.

Wes

 

[RALPHLUCAS]

Pay attention to what N JAY says first! Then you can explore why later. Remember, electronics eat voltage and current to keep healthy. Choose their dinner (in this case a battery or ac to dc converter) based on the equipments hunger (voltage and current) requirements. As an example, the radio may indicate a power requirement of 13.8 volts at 0.8 amps (800 ma). Insure that your power source can deliver at least the 800 ma...better if it can deliver a full amp. Like N JAY says, the voltage source can vary + or - about 1.5 volts. The current/voltage regulators in the equipment can tolerate the variation and the radio will operate within design limits. The gel cell, or any other source of DC power will work IF it can deliver the operating current at the rated voltage for a period of time that is USEFUL. Enter AMPERHOURS. If your cell is rated at 1 AH at 12.0 volts, then your radio will operate for a period of about one hour and 15 minuits. Not practical. However, if your cell is rated at 20.0 AH at 12 volts, then the radio will operate for nearly 25 hours! Much moe better! Therefore, the answer to your question regarding gel cells involves the radio's voltage rating, it's current requirement, and the lenght of time you want it to operate from that source if it is a battery... the amper hour rating.