You're out of luck on the electronic ballasts. Those lamps require a starter, and the lamp technology falls into the 'preheat' category.
While they may work on an electronic ballast, they are not recommended by the manufacturer to be used that way. Your best option is to find someone who has made an exposure unit and see if any of them have successfully used electronic ballasts. I can't speak from personal experience either way.
If you were using 4' lamps, this would be an easy issue to solve, but the shorter lamps are a bit of a problem.
It looks like the aquarium people are into this as well. You might want to take a look at this:
If you are interested you can find out more stuff by searching for ODNO in Google.
One of these days I am going to give this a try.
Originally Posted by Michael Mutmansky
Patrick, in case you (or someone else) is interested I have three UltraLux Combination Ballast units for sale that may work for you. They are Instant Start Electronic Ballast for use with 1, 2, 3 or 4 tubes, including T5, T8, T10 and T12 style lamps. Each of these ballasts would run up to four F20 T12 bulbs or four F40 T12 bulbs. I just checked with www. fullspectrumsolutions.com to make sure about this.
I bought these units several years ago to upgrade my 12 tube F40 T12UV unit but never got around to doing it, and now that I have the Amergraph ULF-28 unit I have decided not to do the upgrade. These ballasts have never been used, in fact, are still in their original shipping box. I will sell all three for $70 plus shipping, which is a lot less than I paid for them. They were advertised for high power factor, though I don't find the specifics on the unit itself.
Anyway, I am fairly certain that this is a pretty good deal since original price was about $50 per unit.
UltraLux ballast are sold through www. fullspectrumsolutions.com, but these units are several years old and no longer on their web site.
Last edited by sanking; 11-06-2006 at 06:53 PM. Click to view previous post history.
Paul, thanks for the link. Their link to BallastWise has a lot of options.
Sandy, I'm out of town for a few days, I will get back to you soon.
What would people recommend for a 24 inch uv light source. I just don't have the room for a larger unit.
Again thank you everyone that has responded.
I have a box with 12 of the 24 inch tubes and 6 of the RL2SP20 TP ballasts. It all works fine but if I could increase output with a different ballast I would be very interested to hear about it. Many of my printing times with negatives developed in a pyro formula are in the 30-60 minute range and shorter times would be very welcome.
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With 24" tubes I would recommend about twelve tubes spaced 1-1.5" apart. This spacing allows placing the printing frame at about four inches from the bulbs, which will eliminate any possibility of uneven distribution of the light. The best tube overall in my opinion is the BL, and there is no difference so far as i can tell between Sylvania, GE and Phillips. The BL tube works equally well for dichromated colloid processes and iron processes, which covers most of what we do. If you are only interested in printing with the iron processes the SA tube is a good tube, but not better than the BL IMO. Some people claim it is faster, but I tested the two types in the same printing unit and in every test the BL printed as fast or faster than the SA.
Originally Posted by Patrick Kolb
Some people have also reported faster printing times using HO (high output and VHO (very high output) tubes and ballast. For example, normal 24" tubes are 20 watts, HO tubes are 40 watts and VHO tubes are 75 watts. Again, I compared printing speed with regulr tubes and ballast and VHO tubes and ballast and while there was some gain in printing speed the considerable extra expense is hard to justify.
I strongly recommend electronic ballast over magnetic ballast. The gain in output can cut printing times by 1/4 to 1/2 of a stop.
What kind of print times are people getting with non-pyro negs using the kinds of light boxes being discussed here?
Originally Posted by Ray Bidegain
With kallitype and palladium my print time with a Stouffer step wedge negative is about two minutes with a bank of BL tubes, about one minute with the AmerGraph ULF-28. Exposures for digital negatives on Pictorico are about 1/4 more.
Originally Posted by cperez
On the other hand I have some over-exposed negatives that take as much as 1-2 hours to print. Printing times are determined by shadow density, and a well-exposed negative, whether developed in a Pyro staining developer or a non-staining developer, will have about the same printing time. Unfortunatley, many people over-expose their negatives, adn over-exposure can result in a huge increase in printing times with a stained negative.
Sorry, have not seen this and may be able to help. Last year I built a 12 blub unit using F20T12 BLB bulbs. Michael was quite helpfull at the time, but when it came time to find ballast, I had the same problem. Someone else had mentioned the Fulham Workhorse electronic ballast, Dan Smith (Wareaglemountain or something like that). Anyway, I contacted them, the website is very good and ended up using 3 of their Workhorse 7 for 12 bulbs (4 per ballast).
There is no warm up, they all start right up, and output is very good, ballast factor > 0.90. I would recommend them, and have, to anyone. They run cool compared to the mag. ballast I had used previously on a 4 bulb unit and print times range from 3 min up depending upon the negative. Of course output might be better if I had started out with BL blubs instead of BLB, but you buy what you can get.
Hope this helps.
Taking this one step further, how do your tube times compare with your spiral bulb (BLB?) setups?
Originally Posted by sanking