Voltage drop on the supply lead
How much voltage gets lost between power supply or battery and radio, and which cross-section is enough for your current and cable length.
Voltage drop on the supply lead
Twelve volts forgive nothing: two metres of cable that's too thin, and the transceiver sags on transmit. The length is one way, the page works out there and back itself.
How the page calculates
- U = 2 ยท l ยท I ยท ฯ / A with ฯ = 0.0178 ฮฉยทmmยฒ/m (copper)
- required cross-section = 2 ยท l ยท ฯ ยท I / (U ยท permitted share)
- Standard sizes: 0.75, 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35 mmยฒ
The two is in the formula because the current has to go there and back; the most common mistake in this calculation is forgetting the return lead. From ten percent voltage drop the calculator warns you.
Related terms
- Shack
- the radio room