13.8 Power Cord Size

[OldModel]

From the various pics of some of the new rigs being sold. It appears that the power cords are sort of small, wire gauge wise. I do not have one in my hand, just an observation from the manufacturer pictures. 15-to-20-amp draw, might require something bigger than 14 gauge? Maybe some are 12 gauge?

 

[brandon7861]

Stranded copper has different resistances based on the strand count and gauge, see here, it's around 2.6 to 2.7Ω/1000' for 14AWG.

Lets say you have a 6' jumper that uses a strand providing 2.7Ω/1000', 6 foot has a resistance of 0.0162Ω. Now double that, because you have two conductors, so 0.0324Ω.

Ohms law tells us that 20A of current through 0.0324Ω will drop a voltage of 0.648v. Ohms law also tells us that with 20A at 0.648v, 12.96w of heat is generated.
On a 13.8v supply, losing over half a volt to the cable means your radio only sees 13.32v, and although that may be acceptable, the cable insulation needs to dissipate that 12.96w of power, which it probably can as it is about 90mW per inch of wire.

Whether the cable can stay cool or not depends on the duty cycle of your transmissions and on the area, thickness and thermal conductivity of the insulation used on the wire. If the insulation can only dissipate so many watt/seconds and you are giving it more that that, it gets warmer and warmer until either the larger temp difference supports amount of energy transfer and the temp stabilizes, or the wire coating melts off. I personally would want a bigger wire if running 20A. There is no reason to give the wire almost 5% of your energy.

 

[OldModel]

I agree. At 20 amps a 6-foot run of 12 gauge. A longer run and would prefer 10 gauge and fuse appropriately. As you said why give up power to the supply line.

 

[Greg T]

I know this doesn't meet the normal consensus, but my Stryker 955 is idled at 14.5V, and on AM using a 10W deadkey it used to drop to 13.9V. After building an 8GA power wire, the voltage now holds at 14.3, even during modulation. Take that for whatever it means.

 

[nomadradio]

The longer the wire run, the fatter it needs to be.

73

 

[OldModel]

I know this doesn't meet the normal consensus, but my Stryker 955 is idled at 14.5V, and on AM using a 10W deadkey it used to drop to 13.9V. After building an 8GA power wire, the voltage now holds at 14.3, even during modulation. Take that for whatever it means.

Do you recall what the 955-power supply line gauge and length was originally? Thanks

 

[n1wom]

From the various pics of some of the new rigs being sold. It appears that the power cords are sort of small, wire gauge wise. I do not have one in my hand, just an observation from the manufacturer pictures. 15-to-20-amp draw, might require something bigger than 14 gauge? Maybe some are 12 gauge?

Check out this website to get an idea of what you need.
Note: I don't work for Blue Sea Systems.

Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance

www.bluesea.com

 

[OldModel]

Check out this website to get an idea of what you need.
Note: I don't work for Blue Sea Systems.

Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance

www.bluesea.com

Thank you, very nice easy to read chart. I have always gone by the less the 3 percent loss.

 

[Greg T]

Do you recall what the 955-power supply line gauge and length was originally? Thanks

I'm not sure. The original is 12ga I think, possibly 14ga. I know the V2 is heavier than the V1. Standard length I THINK is about 6'.

 

[Keto]

I'm not sure. The original is 12ga I think, possibly 14ga. I know the V2 is heavier than the V1. Standard length I THINK is about 6'.

I know the Workman CB3AXX
I put on my v2 was 12gauge and it was heavier duty. I'd like to try a bigger gauge though.

 

[Greg T]

I know the Workman CB3AXX
I put on my v2 was 12gauge and it was heavier duty. I'd like to try a bigger gauge though.

I got hold of some of those new, fresh plugs and used 8ga. It wasn't easy and took a bit of surgery inside the plug to allow the insulation to fit, but I made up a few of them. They worked perfectly and went from dropping more then .6V to only dropping .2v or so. I understand that it isn't much and makes no real difference in the radio's performance, but... my OCD, ya know?? LOL

 

[Keto]

I got hold of some of those new, fresh plugs and used 8ga. It wasn't easy and took a bit of surgery inside the plug to allow the insulation to fit, but I made up a few of them. They worked perfectly and went from dropping more then .6V to only dropping .2v or so. I understand that it isn't much and makes no real difference in the radio's performance, but... my OCD, ya know?? LOL

So you use the Workman plug end or other ones that had no wire attached to start with?
A gain is a gain I suppose.

 

[Greg T]

So you use the Workman plug end or other ones that had no wire attached to start with?
A gain is a gain I suppose.

Yes, I used fresh plugs that came with new inserts and soldered them up. The plugs are in two pieces, held together with screws

 

[Keto]

Yes, I used fresh plugs that came with new inserts and soldered them up. The plugs are in two pieces, held together with screws

Where do you find something like that ? I've searched around on the net but no luck.

 

[Greg T]

Where do you find something like that ? I've searched around on the net but no luck.

I looked forever until I stumbled upon this guy. Can't remember the part number. Like a dumbass, I didn't write it down. On the good side, He DOES have what you need and is very prompt with email questions. I THINK, this is the one you need. It is a take-off, but comes with fresh pins: CB3PP-FP take apart 3-pin plug, fresh pins crimp/solder onto wire to build power cord