How to replace the bulb on this old stern light?
- Thread starter sv_telemachus
- Start date
William_H
Well-Known Member
Can't help with how to dismantle case. However would ask the question,have you got a suitable LED bulb replacement. My guess is that the almp contains a festoon bulb mounted vertically. ie a glass tube with filament running one end to the other with contacts each end. In the azimuth field this provides a point source of light from the filament out past the glass lens to cut off accurately at the prescribed angle. ie 22.5 degrees forward of abeam.
Now any LED diode emits light through a lens in one direction with a beam around 30 degrees wide. They are then clustered around to imitate an incandescent bulb. But the point source is not possible. Your best bet then is a festoon type LED replacement something like this 20Pcs DE3022 LED Bulb COB 31mm Festoon White ar Interior dome map Roof Light 12V | eBay
This will work ok but might not meet the requirements of precise angle of cut off. (most of us would live with that) ol'will just waffling
Now any LED diode emits light through a lens in one direction with a beam around 30 degrees wide. They are then clustered around to imitate an incandescent bulb. But the point source is not possible. Your best bet then is a festoon type LED replacement something like this 20Pcs DE3022 LED Bulb COB 31mm Festoon White ar Interior dome map Roof Light 12V | eBay
This will work ok but might not meet the requirements of precise angle of cut off. (most of us would live with that) ol'will just waffling
Concerto
Well-Known Member
Looks more likely the top unscrews for access. Possibly soak with WD40 or similar before trying to unscrew.
PeterBoater
Well-Known Member
abaft of abeam
Praxinoscope
Well-Known Member
I agree with Concerto #3 it looks more likely that it unscrews from the top especially as it looks from the photo’s that the bulb holder is at the top end.
The knurling on thé top ring also suggests that this is the method of entry.
The knurling on thé top ring also suggests that this is the method of entry.
Refueler
Well-Known Member
OK ... I have one of those ... actually I replaced it as the glass was damaged.
The usual problem is that the top which unscrews - the threads and top get 'stuck and it needs 'persuasion' to unscrew - trying hard not to damage the glass and vertical tube .... the vertical tube just sits over the mount and bulb holder held by the top ...
I like the light ... old world ... but because of the glass is crazed on mine - cannot be used anymore.
While holding main body ... unscrew top
Once top is away - the main body can now be lifted off
and bulb replaced
Suggest good smear of something round inside top and threads when re-assembling.
The usual problem is that the top which unscrews - the threads and top get 'stuck and it needs 'persuasion' to unscrew - trying hard not to damage the glass and vertical tube .... the vertical tube just sits over the mount and bulb holder held by the top ...
I like the light ... old world ... but because of the glass is crazed on mine - cannot be used anymore.
While holding main body ... unscrew top
Once top is away - the main body can now be lifted off
and bulb replaced
Suggest good smear of something round inside top and threads when re-assembling.
sv_telemachus
Active Member
OK ... I have one of those ... actually I replaced it as the glass was damaged.
The usual problem is that the top which unscrews - the threads and top get 'stuck and it needs 'persuasion' to unscrew - trying hard not to damage the glass and vertical tube .... the vertical tube just sits over the mount and bulb holder held by the top ...
I like the light ... old world ... but because of the glass is crazed on mine - cannot be used anymore.
While holding main body ... unscrew top
Once top is away - the main body can now be lifted off
and bulb replaced
Suggest good smear of something round inside top and threads when re-assembling.
Incredibly detailed reply, thanks very much!
Refueler
Well-Known Member
Glad to help ...
