LED light questions

[boss subfixer]

This is for a target but I think the real LED experts are here. I have a string of battery operated (three AA batteries) LED lights that Walmart carried during Christmas. There are ten small LEDs in the string with a resistor nestled in the battery box, I only need to use seven of the lights. First question: Do I need to change the resistor because I'm using less LEDs?
The wires used are too big for the size of the mast, I plan on using wire used in telephone wiring because its much smaller and in the old days of mechanical ringers would see up to 110 volts to ring the bells inside so it should handle the voltage from batteries. Question two: Does this sound right to you? I also think I can use the mast, which is made from brass tubing as the ground side of the circuit to save room inside the mast for the operating radar. Question three: does this sound right? There are some unknowns, I don't know the values of the LEDs or the resistor. I know the stripes on the resistor translate to it's value but the high school electronics class I took was many, many moons ago. Any help would be appreciated.
Thanks.
Don

[skip asay]

Do I need to change

<snip> Do I need to change the resistor because I'm using less LEDs?
Yes. Let me know the colors of the stripes and I'll be able to compute what you need.
Don -

<snip> I plan on using wire used in telephone wiring because its much smaller and in the old days of mechanical ringers would see up to 110 volts to ring the bells inside so it should handle the voltage from batteries. Question two: Does this sound right to you?
Short answer is yes but the voltage is not the issue here but rather the amperage. But I know for sure the wire you want to use will carry the amperage.

I also think I can use the mast, which is made from brass tubing as the ground side of the circuit to save room inside the mast for the operating radar. Question three: does this sound right?
Yes. No problem at all.

Skip Asay

[boss subfixer]

Thanks Skip.
I hope I get

Thanks Skip.
I hope I get this right, old eyes a flashlight and a magnifying glass to see this . From the load side, orange, white, black and gold.

On the first and third question I had a feeling the answer was yes but I wanted to double check. The second question to tell the truth I didn't even think of the amperage. Time to get started on the wiring harness.
Take care.
Don

[skip asay]

Don -

If I've remembered my

Don -

If I've remembered my Ohm's Law correctly, you'll need 52 Ohms resistance. What you have now is 39 Ohms. According to the Radio Shack web site, the closest you'll be able to get is by adding a 10 Ohm resistor (Part #271-1101) IN SERIES with the 39 for a total of 49 Ohms or a 15 Ohm (Part #271-1102) for a total of 54 Ohms. Either one will work but the 54 Ohms will be a little less of a load on the battery with a little bit less brilliance.

Hope this helps.

Skip Asay

[boss subfixer]

You da man Skip! Thats

You da man Skip! Thats what I like the most about this site. Someones always willing to help.
I think I'll go with the 49 ohms, I want the lights to really show, as for the battery I'm going with the battery box that came with the lights. Nothing fancy but it has it's own on/off switch. Maybe later I'll go with an electronic switch through the radio. I just want to get her in the water first then I'll tweak it here and there.
Don