A change of heart, Scubapro D420

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Been following this thread forever , reminds me of 1968 when my brother and his friends were always fine tuning their MG Sports cars , they loved them but never , never got them right , thanks guys ...

Reminded me of a joke:

"Why don't the British make TVs?

They couldn't figure out a way to make them leak oil"

I used to own and work on old minis, a mechanic friend of mine (RIP JP) hated them, he used to say "if you can touch it you can't see it and if you can see it you can't touch it".
 
I'm only interested because I'm OCD and would like a matching pair. Of course I'm in no financial position to even consider that.

Given how much little use a back up gets my logical mind says it would be a waste of money even if I could afford it.

I'm interested to know if it could fill that role though.

I think your little C370 is a great match for the D on back up duty.
I did my first dive or the year in Hokkaido yesterday. Using your G250v as my primary and a c370 as backup. Works great.
 
I did my first dive or the year in Hokkaido yesterday. Using your G250v as my primary and a c370 as backup. Works great.

Happy to hear that. Thanks for posting. They are great regs. Still wish I'd kept two for myself, they are certainly the best G250. Oh well. By the way how do you like the C370?
 
Here's a little more data, and it looks good for the D420.
First, the ground rules: any regulator with a cracking effort less than 1 1/2", inserted diaphragm down, will open its valve and flow air. That's the definition of "the sink test", yes? Whether or not it stops depends on two factors: 1) whether the Venturi kicks the reg into true freeflow, and 2) whether water can seep into the case, fill it up, and neutralize the negative pressure created by the escaping air.
The attached 5-sec video shows a D420 and a G260, both on the same Mk17 first stage, being dunked in the water. Both were tuned to 1.1" cracking effort.
Two previous tests (not shown) are not surprising:
1. With the Pre-dive switch in the "Dive" position, both regs dunked "diaphragm down" went into full freeflow and sprayed water all over the bathroom!
2. With the Pre-dive switch in the "Pre-dive" position, if I inserted either reg in the water with the diaphragm down and then kept the mouthpiece facing perfectly up, the regs didn't go into massive freeflow, but the valves never closed, either. The escaping air kept all water out of the case, and air continued to flow, because the distance from the diaphragm to the top of the mouthpiece in inches was greater than cracking effort.

So, on to the test. I attempted to simulate a water entry in disadvantageous conditions. The regs were held nearly diaphragm down, and clearly in a position that would cause the valves to open. Both were tuned to the same cracking effort, and the D420 was further challenged by removing the mouthpiece restriction. For visibility in the video, the pink mouthpiece was cut to just leave the restriction on the G260, with no bite blocks. I don't think I'll regret sacrificing my pink mouthpiece, do you?
As you can see, the D420, even without a mouthpiece restriction, displayed no inclination to freeflow. Despite equal or better air delivery than a G260, and an absent mouthpiece to facilitate possible freeflow, the D420 stopped leaking faster than its sister.

I think she'll do just fine as an octopus.
Of course, ya gotta remember to put your octo in Pre-dive! :D
 
I’ve been doing my swim out and start of dive with the 420 in predive and even do a few minutes of the dive before switching, no reason beyond noticing how it breaths just fine in than position and when I switch it to “dive” it’s always a nice wow, nice moment. I always try to keep it mouth piece down when walking in the water because in freeflow it moves a lot of air.
 
Picked up a cheap G250, I think it matches the D nicely.


F55EDF34-3373-410B-9129-4D25CC0494A5.png
 
a cheap G250


No such thing as "cheap" G250 or anything SP! Inexpensive, maybe but never "cheap"!!


"Cheap" is left to other wannabe companies.
 
https://www.shearwater.com/products/peregrine/

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