Jobo ATL-1500

[gliderbee]

I just got a Jobo ATL-1500 for a very reasonable price.

Reading the instructions, it should be connected to a tempered water supply, and I have some questions about that:

- is a normal houshold thermostatic tap sufficient ? If so, I might install one instead of the "normal" tap that combines warm and cold water.

- does it have to be connected to tempered water only to diminish start-up time or does it use fresh water from that tap to rinse between processes ? If not, I might just connect it to a cold water supply, which would make things easier.

Thanks,
Stefan.

[Joanna Carter]

The tempered supply is purely to provide wash water between chemistry cycles.

I use a 25 litre bucket, with a Nova submersible heater and a caravan water pump, to supply the tempered water to the low pressure inlet rather than going to all the trouble and expense of providing a high pressure (mains-fed) thermostatic solution.

The tempering bath in the processor can be filled with a jug and will come up to temperature using its own internal heater.

[gliderbee]

Hi Joanna,

thanks for your answer.

How does the caravan pump "know" when water is needed at the low-pressure inlet ?

I have a warm water supply (a quite large electric boiler) in my darkroom, and cold water, of course, but when mixing, the water is always a bit cold during the first moments until the warm water arrives. Why would I need a high-pressure solution ?

Thanks,
Stefan.

[Joanna Carter]

Hi Stefan

How does the caravan pump "know" when water is needed at the low-pressure inlet ?

The caravan pump is plugged into a 1/4" jack socket, next to the low pressure inlet. This only supplies power to the pump when water is required.

I have a warm water supply (a quite large electric boiler) in my darkroom, and cold water, of course, but when mixing, the water is always a bit cold during the first moments until the warm water arrives. Why would I need a high-pressure solution ?

The problem with most solutions fed from the water system is that it can take time for the water to arrive at the correct temperature. Some people leave the supply running on a bypass drain, in order to ensure that, when the processor requires water, it is already running at the right temperature.

If you have a solution for ensuring that the water, controlled by a thermostatic valve, starts running at the correct temperature then use the high pressure feed.

I find the low pressure solution much easier to manage, even though there is always going to be a short length of hose from the bucket to the processor that might not be at quite the right temperature, this doesn't seem to affect the results I am getting with E6 film.

For B&W film, the temperature is nowhere near as critical and, as long as the water is within a few degrees of processing temperature, you shouldn't have any problems with a thermostatic high pressure system.