[TenTec] pilot light bulbs

[Dr. Gerald N. Johnson]

On Mon, 2008-08-04 at 18:18 -0400, Rick Denney wrote:
> Dr. Gerald N. Johnson writes...
> 
> > I prefer a resistor to a gaggle of diodes. The status lites panel on an
> > 821A-1 transmitter contained 41 or 42 lamps, all running 28 volts. Takes
> > at least 4 diodes to make a useful drop for each lamp, or 165 diodes per
> > radio.
> 
> Of course, you are talking about a Collins transmitter with 42 panel
> lights driven probably from a range of different source points within
> the circuit boards, while I am talking about a Ten Tec tuner, with
> three or four panel lights being the only items driven by directly
> wired outside power. And you are talking about a voltage that needs
> four diodes to get a 10% drop while I'm talking about 12 volts that
> only needs two. And you are talking about mass purchase for a
> production situation while I'm talking about a mode by the owner to
> one piece of equipment. We are both talking about something we do to
> avoid the inconvenience of having to replace bulbs for a system that
> already works fine as it is. Diodes or resistors--probably doesn't
> matter much--use what's in the junk box. I think I'll make a new RCA
> plug for that power connection and mount those whatever devices in the
> shell of the plug.
> 
> Rick, KR9D
> 
But I also think that reducing the turn on surge current by 60+% that
the resistor accomplishes compared to the 10% reduction of the diodes
also significantly enhances lamp life.

73, Jerry, K0CQ