[Boatanchors] LED's instead of lamps in boatanchors???

[brianclarke01 at optusnet.com.au]

> WE0H <we0h at yahoo.com> wrote:
> 
<snip> The bonus of using them is they give off zero heat 
> which is much better for any plastic lensed meter.

Hmmm...
Usual fwd voltage for an LED is about 2 V. Usual current is about 20 mA.
So, power consumed is about 40 mW. The lumens per watt is so low that about 85% of this is given off as heat, say, 33 mW.
Now an incandescent lamp is probably 6.3 V at 0.15 A = 945 mW, with similar illumination efficiency; so, about 750 mW is given off as heat.
So, it's not zero heat, but it is quite a bit less.
73 de Brian, VK2GCE.