[Boatanchors] #44/47 Buld replacement with LEDs

[Garey Barrell]

Mike -

Yes, it really should.

I don't recall the numbers, but the bulb should be connected between Pins 4 and 6.

Seems like the resistor was 43 or 47 ohms, 2W.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>


Michael A. Bittner wrote:
> Thanks Gary, that clears up some questions. I'd always heard that
> damage could be done to an AA5 if a burned out pilot bulb were not
> replaced.
> Next question: Should a 35W4 always have a pilot bulb connected, as in
> an AA5, for proper operation.  My Knight Ocean Hopper has a 35W4, but
> no pilot bulb.
> Mike, W6MAB
>
>     ----- Original Message -----
>     *From:* Garey Barrell <mailto:k4oah at mindspring.com>
>     *To:* boatanchors at puck.nether.net
>     <mailto:boatanchors at puck.nether.net>
>     *Sent:* Friday, February 04, 2011 7:38 PM
>     *Subject:* Re: [Boatanchors] #44/47 Buld replacement with LEDs
>
>     The 'tap' on the filament is NOT a 'center tap'.
>
>     The problem with this system is that of course the bulb is
>     subjected to
>     the initial surge of current when filaments are cold, causing that
>     flash
>     that you see at turn-on.
>
>     Worse still is that when the bulb inevitably burns out, the excess
>     current is forced through that portion of the filament in the
>     rectifier,
>     causing it to fail open.  LOTS of rectifier tubes killed when the
>     owner
>     noticed the bulb was out, but didn't want to take the radio to the
>     shop
>     for repair!  Then he got to pay for a bulb AND a tube!  :-)
>
>     73, Garey - K4OAH
>     Glen Allen, VA
>
>     Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
>     and TR-4/C Service Supplement CDs
>     <www.k4oah.com <http://www.k4oah.com>>
>