Durst 138S Replacement Bubs

[Allen in Montreal]

Final group of pix.
One pix is a repeat, I forgot to label the bulbs.

[Len Middleton]

Allen,

A little more informatioin please...

1. Did you try the same evaluation for the Durst L184 condenser enlarger? If so, what are the results?

2. What is the application for the three way bulb with the E39 base? What is the approximagte diameter of that bulb (G40 => Globe shaped envelope, 40 x 1/8" diameter)?

Thank you for your efforts,

Len

[Allen in Montreal]

Hi Len,

I will measure the bulbs and post tonight.

I only tested in the 138.

But the man I got my 1200 from had been successfully using the 3 way 130 volt bulb (at left in the picture below, next to a standard PH213) in his 184.
I do not doubt the G40 would work as it is larger than the original bulb. I am rather sure the 3 way 120 volt would work also as it is only slightly smaller than the original.

[GeorgesGiralt]

Hello !
I own the Laborator 1000, 4x5 version of the 138. (same vintage). As I'm living in Europe, I need 220V bulbs. And they're out.
So I made experiments. Durst state that the 150 and 300 W bulbs specified for this enlarger should have a bulb size of 100 mm (4") for even lighting on the baseboard.
These bulbs (the 250 and 300W where also specified for the 138.
The only available bulbs in Europe right now for enlarger use are at max 250 W but with the globe of 65 mm diameter. Even with accurate centering it is very difficult to even the light on the baseboard.
So please consider the apparent diameter of the bulb the condenser see...
I had success by putting a frosted glass between the bulb and the mirror. This way lighting difference on the baseboard is less that 1/3 of a stop which is very good.
I would be glad to get my hands on 100 mm diameter bulbs in 220V and 150 or 200 W at affordable prices.

[Michael Clark]

WOW, thats great Allen.Thanks for taking the time and effort, give's new hope for an old enlarger!

Mike

[Allen in Montreal]

Hi Len,

Here are the measurements for the bulbs I have on hand, I have a note somewhere with the original bulb, but since I don't have anymore on hand, I will have to dig that note up if I can.

The packaging does not give an application for the E39 base 300 watt.


PH302:
3 1/2" inch globe, 7 1/2" in length E26 base.

G40 150 watt E26:
4 1/2" globe, 6 1/2" in length E26 base.

3 way 300 watt 120 v E39:
3 1/4" globe, 6 1/2" in length. E39 base.

3 way 300 watt 130 v E39:
3 1/2" globe, 6 1/2" in length E39 base.

GE long neck: 3' globe, 6" in length
I mentioned these were Sylvania but they are GE. Labeled Canadian National.
I bought a darkroom kit from CN Rail 20 years ago and these bulbs were in a box marked "Durst".


PH212 / 213
2 1/2" globe, 4 1/2' in length E 26 base.


PS:

There were some very large globe (as in 6inch globe) 500 watt bulbs, the dealer would love to get rid of, if anyone wants to try them in a 184, let me know and I will go back and buy them for you. They were not true photo bulbs based on the coating, but I bet they would work with a slight diffusion on the heat absorbing glass holder in the 184.

[Graybeard]

Very nice work Allen.

In the spirit of being helpful, I'll repeat myself regarding the length of the G40/150W Bulb. If the neck length is shorter than what you enlarger requires, you can easily and inexpensively make up the difference with extension adapters available at hardware stores and the big box home centers.

I used two of these two bring to the center of a G40 to the same location as the center of the original PH 203 bulb in my Elwood 5x7.

Not every supplier in the US has the G40 in 150W size. Lowe's stocks them, Home Depot does not. There are plenty of these bulbs available from the web light bulb specialists.

[Allen in Montreal]

Very nice work Allen.
...... extension adapters.......

Not every supplier in the US has the G40 in 150W size. Lowe's stocks them, Home Depot does not. There are plenty of these bulbs available from the web light bulb specialists.

Thank you on two levels, for the kind words and for pushing me to try the G40.
The 138 and the 184 should not require and extension as your Elwood did.
The G40 and the 300 watt lined up perfected with the built in bulb placement system.


I would be curious to know if anyone has first hand knowledge if a lamp running at say 2700k instead of the standard 3200k would in fact (or not) affect the paper speed and MG filter responsiveness?

[Len Middleton]

Allen,

The notes I have on the Thorn bulb are:

Bulbs have unusual envelope sort of a cross between a standard “A” and “G”. Diameter is approx. 4-1/4” (e.g. G34 or A34), and MOL is approx. 7-3/8”.

Looking further in an old GE lamp catalogue, it looks like the envelope is a "G".

Best regards,

Len

[ac12]

Thanks Graybeard and Allen, this is great info.

I just picked up a Durst L1000, and using the info you provided, I figured my "affordable" replacement bulb is a white G30 bulb. w/o this info I would have passed on the enlarger simply because of lack of a bulb for 4x5.
Now the only thing left to do is figure out what wattage(s) I want 40, 60 or 100w. On my smaller Durst M600 I was using a 75w bulb and even then I sometimes wish I had a lower wattage bulb, to give me more workable exposure times. Heck at the cheap price I might get all 3 (40, 60 & 100w) then use whichever I need for the particular printing job.