Data General Nova 3 and 6045 Drive Questions

[Mark J. Blair]

> On Jun 12, 2016, at 00:44, Henk Gooijen <henk.gooijen at hotmail.com> wrote:
> 
> Just like Mark, it's about time to spend some time on my NOVA3.
> I will be following this with interest!

Yay!


> Were all bulbs on the front panel of your NOVA intact Mark?
> Or did/do you also have dead lamps?  Know of a source where to buy them?

I did have some dead bulbs. My memory is foggy, but I found some archived emails from when I discussed the bulb replacement two years ago. I think that I used number 2185 bulbs that I ordered from Digi-Key. Here are the old messages in my archive:


On Jun 14, 2014, at 09:21, Mark J. Blair <nf6x at nf6x.net> wrote:
> Do any of y'all know the bulb number for the fragile little wire-leaded bulbs used in the Data General Nova's switch console? I have at least one burned out, and a couple have snapped off. I measure about 15V across the bulbs on my machine, but I don't know yet whether that's the correct voltage, nor do I know the nominal voltage, current or brightness ratings of the correct bulbs.
> 
> Picture:
> 
> https://twitter.com/nf6x/status/477846674543362048/photo/1
> 



On Jun 15, 2014, at 09:06, Mark J. Blair <nf6x at nf6x.net> wrote:
> 
> On Jun 15, 2014, at 08:49 , Toby Thain <toby at telegraphics.com.au> wrote:
>> Via email, snarfusmaximus writes, "I replaced mine with yellow LEDs with a series resistor."
> 
> That's a pretty tempting solution. Those original bulbs are quite fragile, and appear to be quite prone to suffering lead breakage near the glass seal.
> 
> Here's what I just posted on VCF, for those (few?) folks who are here but not there:
> 
> -------- 8< cut here 8< --------
> 
> Regarding the console bulbs, I found that one of mine that snapped off at the base still has an intact filament. I was able to probe the wires at the glass seals to light it up and measure current. The bulbs are normally powered from an unregulated 14V rail as I understand things, and I measured the voltage at around 15V on my machine. The broken-off bulb draws 39mA at 14V and the filament color is quite orange. It draws 50mA at 28V and has a normal-looking color temperature. I conclude that the original bulbs were probably designed for 28V operation or so, and are used at lower voltage in the Nova 3 to increase service life (?).
> 
> McMaster-Carr and Digi-Key both have some bulbs that look like possible substitutes. I think I'll try some 2185 bulbs from Digi-Key since I'm ordering other stuff from them anyway, unless anybody has a better confirmed cross-ref. Those are 28V 40mA bulbs.
> 
> I also received an email from another collector who used KH 4-280-040A-1 bulbs from KH Lamp in his Nova. He reports that he got them from Swedish distributor Elfa as part number 33-657-98. That's a 28V 40mA T1-1/4 bulb.


On Jun 15, 2014, at 14:16, Mark J. Blair <nf6x at nf6x.net> wrote:
> 
> 
> On Jun 15, 2014, at 12:51 , Brent Hilpert <hilpert at cs.ubc.ca> wrote:
>> Here's another testimonial for a Nova, this fellow mentions replacing them with 28V/0.04A bulbs, but doesn't say how he knows those specs:
>>   http://www.foxdata.com/blog/?tag=nova-312
> 
> He's emailed me about his project. I can't access his web site at the moment, and we're planning to look into that tomorrow.
> 
> 
>> The Hudson 2187D type he mentions maps to Chicago CM-2187, listed at Mouser:
>>   http://ca.mouser.com/ProductDetail/Chicago-Miniature/2187/?qs=qp111mKzDjgelZXllf1Wrw==
> 
> Cool. If the 2185 bulbs that I'm ordering from Digi-Key don't work well, I'll try some 2187 bulbs.