[Heath] Light bulbs for HW/SB transceivers

[Kenneth G. Gordon]

On 13 Jan 2013 at 18:41, Glen Zook wrote:

> They are not 12.6-volt bulbs.  The pilot lamps are wired either in
> series with each other or are wired in the series-parallel arrangement
> with all of the tube heaters ("filaments").  The bulbs themselves are
> just plain old #47 and are available all over the place.  Radio Shack
> has them (although slightly higher priced than the normal electronic
> parts outlets).

Another point should be made here: there is a Heathkit service bulletin which 
directly addresses the pilot lamp issue for the HW-101 or SB-100/101/102.

Some kits were supplied with #44 pilot lamps, instead of #47 bulbs: the #44 
lamps draw 250 mA each, and thus unbalance the series-parallel filament 
string.

The #47 bulbs draw 150 mA each, which is correct.

Always use #47 pilot lamps, and make sure your rig does not have #44 
lamps in it instead.

Ken W7EKB