More than halfway done building lamps into holders

 PROCESS RECAP

Since my supply of new 2114 miniature incandescent bulbs is going to be delayed at least another week or so, I am reclaiming bulbs soldered onto my prior approach to a lamp holder - wire leads wrapped around a 2 position header strip then insulated with goop since the bulb can bend and twist bringing its wire leads together. 

Once the bulb is removed from the old header, it is cleaned and ready to solder into a new holder. To construct the holders, I cut two pin segments from a new header strip, insert one end in a breadboard to act as a jig, and snap the nylon holder down over the header segment. This creates a holder which has the two pins separated by a nylon barrier, two side arms that nestle the T 1 1/4 size bulb in place, and allows access to solder.

Fortunately, the bulb sitting in the holder needs only a very short segment of wire lead and it can reach the top of the header pin. Something in the range of 1/4" is adequate. That allows the reuse of the old bulbs since I can cut away twisted ends without loss of any bulb. 

The goop makes this desoldering much harder than if I simply had to heat and remove leads that were wrapped around the header pins. I make use of a large tip on my Weller soldering station to do the removal, transferring heat through the goop but gumming up the tip quickly. Lots of retinning, tip treatment and cleaning is needed as I work my way through more than 150 of the old bulb assemblies. 

Installation of the cleaned bulb in the new holder is quite easy. I use my thinnest tip on the Weller station, push the bulb down within the holder arms, push the lead in contact with the pin, apply the iron and solder the connection. A quick flip of the holder and I repeat for the other bulb lead and header pin. 

I set up a test station on the breadboard connected to my ohmmeter. Popping each new lamp into the station tells me if this is an open circuit, a short, or the bulb is displaying circa 10 ohms of cold resistance. I know that every lamp I build is working properly before I install them on the PCB.

STATUS

I have cycled between the three process steps - cutting and snapping header strip segments into holders, removing bulbs from the old assemblies, and soldering the bulbs into the new assemblies. This is tedious work due to the need to build 164 lamps for the fully populated IBM 1130 console panel. 

Partially populated board, unfinished holder below

I need to reclaim 66 more bulbs from old assemblies, move them into new holders, and then when my bulb supply arrives I can finish the last 16 lamps which illuminate the unused CE (Customer Engineer) and Synchronous Communications Adapter (SAC) positions. 

I don't have the SCA on my machine and the CE lamps are set up to display diagnostic signals by the use of jumpers when the CE is working on the system. I have better logic analyzer and scope tools, thus am unlikely to make use of the 8 CE indicators. 

TEST FIT CONTINUES TO LOOK EXCELLENT

From time to time, I check how difficult it will be to slide all 164 bulbs into the honeycomb matrix behind the display panel. So far, it has been pretty easy to wiggle it a bit and have all the lamp holders slide into their cells.