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daveco2

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About daveco2

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  1. I'm planning a trip for 12 days in 2023, but could use a little help in choice of month, March-June. The resorts manager says they gets lots of rain in their so-called dry season, so that doesn't matter. He also says it's crowded at the same level during that period. That leaves the choice of season for the Sipadan pelagics and Mabul macro. Has anyone had experience lately in these months at Sipadan? Thanks for any comments. David
  2. Test results. More than you wanted to know? I measured with a micrometer, six O-ring materials for absorption (swelling) with the Microlubrol 50 CST silicone oil and Meikon silicone O-ring grease. The Microlubrol has the same viscosity as olive oil (50CST), and the grease feels the same as honey (7,000 CST). * With Microlubrol: After a week, no change in thickness for Buna-N, Viton, rubber, and wetsuit material. For a yellow silicone Inon O-ring, 7% diameter expansion. For a white silicone Meikon O-ring, 12% diameter expansion. For background, measurement of a dry Meikon O-ring diameter over its length showed a 4.5% variation, max-min. * With Meikon grease: After a week, no change in diameter for the silicone Inon or Meikon O-rings. The various materials were completely submerged in the oil and grease, not the same condition as the line contact for an O-ring around a housing button. The much higher viscosity of the grease (140 times) probably explains its lack of absorption. My view is that lubrication around a sliding shaft seal is important; but that's based on high vacuum experience, quite different from submersion in water. Nonetheless, I'll be using the Microlubrol.
  3. All the great comments much appreciated. Yes, I always soak my gear in fresh water and work all the buttons. But having done that for several years now, and regularly regreased the main O-rings, I'm left with the uneasy feeling that the buttons may be running out of lubricant. I suppose I could try to send my Meikon case back to the factory for service, if they'll accept it; but I don't know exactly what they'll do or how well. I do have a vacuum test system for the housing that I regularly use. My feeling about lubricating the button O-rings comes from having worked with O-rings through a career building high pressure and low pressure gas lasers, and rotating and plunging actuators through high vacuum sliding O-ring seals. I can imagine that a micro layer of lubricant on a housing button rod would be carried through to the seal surface of its O-ring - a good thing. In any event, I have a large stash of O-rings of various compositions: silicone, Buna-N, rubber, and Viton. My plan is to put the lubricant on each one and see if there is any deterioration or absorption. In the past, I have used the standard silicone-based vacuum paste made by Dow Corning on all these with no problem. For high vacuum less than 10^-8 Torr we gave up O-rings and went to soft copper or indium gaskets.
  4. Probably more than anyone wanted to know, but I thought I'd finish up this topic. I followed Architeuthis' lead, but the USA was not listed as a country they ship to, so couldn't place the order; and found no way to contact them. Next, followed the lead given by Meikon in their housing maintenance writeup, what they call "Silicone Pump" to Divetek in S. Africa. That product had changed names and was now available only as a spray in the US. I wound up with a product from Amazon, called MicroLubrol 200 Pure Silicone Oil 50 CST viscosity. Turns out, I had done viscosity measurements in my lab and figured that 50 CST would be about right for a lube around push buttons. So, I'll give this product a try.
  5. Thanks, Wolfgang. Much appreciated. My housing has been working fine; but it's been a few years since I did anything but clean the main O-rings, and was wondering about the button seals, considered taking all of them entirely apart. I read this article and was hoping I could get away with simply a drop of silicone fluid. https://meikon.com.hk/blogs/news/underwater-housing-maintenance
  6. I've read that it's a good idea to periodically put a drop of silicone lubricant around the shafts of the various actuator buttons on a housing to keep the o-rings in good shape? Is this true? Any recommendations for a silicone lubricant? Thanks for any comments, Dave
  7. Well, I tried a couple of circuits. The first circuit published here by uwdiy using an IRF 540, and the second suggested by Packhorse using AMC7135 current regulators. (I went up to 4 regulators in parallel-1.4A total). Both circuits flashed the LEDs, but the LEDs were not bright enough to trigger my Z330 even when brought up against the receiver.
  8. Thanks, Rick For the useful positive report. Parts for my DIY project arrive tomorrow from Mouser. Depending on how that project turns out, I may revisit the TRT purchase. Either way, I'll report back here.
  9. Thanks, Tim I read that one. Lots of detail on fiber optics and interfaces. What I'd really like to read about is reliability of the recent model TRTL trigger and accuracy of its TTL function. There also isn't anything from a wider Google search, except for some negative comments about the build quality of a prior TRTL model. In any case, I've about made up my mind to build my own manual trigger based on a design from WetPixel. I figured out on my trip the last several weeks to the Philippines (Dumaguete and Moalboal) that once quickly dialed in, the exposure doesn't change much target-to-target, and anyway, it's easily adjusted in post processing. David
  10. Thanks, Tim Yes, I did several searches with different key words, but didn't get anything relevant. Will keep trying. Dave
  11. Is anyone using these TTL strobe triggers? How do you like them?
  12. Hello, Are there any users of this combination who can make comments? Thanks for any information, David
  13. Hello, I'm Dave, home waters Southern California, Catalina, and Redondo shore diving. It's been a long two years, and now looking forward to getting started again with a trip to the Philippines in two weeks. I'll let you know how it goes. Dave
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