<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Cliff,</div><div id="AppleMailSignature">my original buck / boost LED drivers made audible noise at certain</div><div id="AppleMailSignature">settings. I mentioned this to an electronics friend, who said that </div><div id="AppleMailSignature">it was to do with the tuning of the unit. </div><div id="AppleMailSignature">I had 10 new units made up for me in China, at a factory that seems </div><div id="AppleMailSignature">to produce a lot of these buck / boost DC drivers. I made mention</div><div id="AppleMailSignature">of the noise problem & was specific that I wanted a 36V fixed output,</div><div id="AppleMailSignature">along with dimming & on off switch.</div><div id="AppleMailSignature">These new units are a lot audibly quieter. I am guessing they can achieve</div><div id="AppleMailSignature">this easier by not having to also cater for the wide output range.</div><div id="AppleMailSignature">They can operate from about 12V through to 54V. I am now wondering</div><div id="AppleMailSignature">whether having a narrower input power band would help even more.</div><div id="AppleMailSignature">Whether the audible noise corresponds to electrical noise in the frequency</div><div id="AppleMailSignature">that interferes with your coms, I do not know.</div><div id="AppleMailSignature">I can send you one of these drivers for testing if you like, as this is a problem</div><div id="AppleMailSignature">I will be encountering. Just send me your address.</div><div id="AppleMailSignature"><a href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a></div><div id="AppleMailSignature">The units are designed to output 75W, but this can be dialled down on</div><div id="AppleMailSignature">the dimming pot, or buy a more suitable pot. Again, if the unit ( in your case) </div><div id="AppleMailSignature">was designed to output at 50 W then possibly there would be less noise. </div><div id="AppleMailSignature">It would be interesting to see if dimming them increased the noise.</div><div id="AppleMailSignature">Alan</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"><br><br>Sent from my iPad</div><div><br>On 27/08/2017, at 7:25 AM, Cliff Redus via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div>That is an interesting point about the even with your OTS SSB-2010 unit running off AA batteries, you hear noise when the DC-DC converter is on. I was hoping this noise filter I ordered would do the trick but it sounds like maybe , maybe not. I have a friend that works for ATT and he also thinks it noise coming in on the power to the OTS unit. What I am hoping it is not is acoustic coupling. My transducer is mounted to the FRP shell behind the pilot. I am hoping it is not picking up this noise through vibrations through the FRP shell.</div><div><br></div><div>I well let you know what I learn from the test.</div><div><br></div><div>Cliff</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Aug 26, 2017 at 11:40 AM, Alec Smyth via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Cliff,<div><br></div><div>I'll be following that with interest! In Shackleton I have a DC-DC converter to step down the 36 volts to 12 for hotel loads. The 12V converter output is connected in parallel to a small 12V battery and to hotel loads, the idea being that I charge the 12V battery pre-dive and switch off the converter while diving to avoid interference. The OTS unit I use in native mode, on separate AA batteries to avoid electrical noise, but despite this if the DC-DC converter is running it interferes with the comms to the point of rendering them useless. If the noise filter is successful it would let me charge the hotel battery from the big banks while diving, or use the converter as backup, without losing comms. </div><div><br></div><div>Best,</div><div><br>Alec</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Aug 26, 2017 at 11:11 AM, Cliff Redus via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.<wbr>org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid"><div dir="ltr"><div>As a lot of you use the OTS underwater comes on your boats so I thought I would share with you an issue that came up on the Islamorada trip. When I tried to use the OTS comms with my new LED lights on, I noticed a loud hum in the OTS headset. When we got the boat back on the dock, we did some testing plugging and unplugging the Subcon disconnects to each of the four lights. What we found was a cumulative affect, each light adding to the noise. These lights use a switching LED driver. There seemed to be the same noise level when the lights were on submerged as on the surface so think the noise is electrically coupled not acoustically. On my boat to keep from changing out AA batteries in the OTS SSB-2010 unit, I removed the battery pack and replace it with an circular electrical disconnect that brings in 12VDC from boat bus. I use a DC-DC converter to power this bus. I am thinking this is a non isolated converter. I spoke with the OTS engineers and they said it was a common problem when folks that make this change and the solution was to use a DC noise filter on the power supplied to the unit that isolates both the positive and negative power feeds going into the unit. They also suggested using an isolated DC power supply. To test this I ordered a Palomar Engineers <span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt">RFI-DC-30 which is a common mode noise filter <a href="http://palomar-engineers.com/rfi-kits/home-alarm-system-rfi-kit#!/DC-Voltage-Common-Mode-Noise-Filter/p/74356250" target="_blank">http://palomar-engineers.com/r<wbr>fi-kits/home-alarm-system-rfi-<wbr>kit#!/DC-Voltage-Common-Mode-<wbr>Noise-Filter/p/74356250</a>.</span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt">Also I hear the thrusters as well as the emergency pinger in the OTS gear.</span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt"><br></span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt">In the next couple of weeks I plan on doing a shop test to see if this works. I will report on what I find.</span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt"><br></span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt">Regards</span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt"><br></span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt">Cliff</span></div><div><span style="color:rgb(17,17,17);line-height:115%;font-family:"Arial","sans-serif";font-size:11.5pt"><br></span></div></div><div class="gmail_extra"><br><div class="gmail_quote"><span>On Mon, Aug 7, 2017 at 6:26 PM, Cliff Redus <span dir="ltr"><<a href="mailto:cliffordredus@gmail.com" target="_blank">cliffordredus@gmail.com</a>></span> wrote:<br></span><div><div class="m_-4085103115085192470h5"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid"><div dir="ltr"><div>Big thanks Doug for posting dive report and for you and your mom and dad for hosting us last week. You guys did a magnificent job. This was the best sub trip of my life! </div><div><br></div><div>I spend the day organizing the video and pictures from the trip and mailed them to Alec who has graciously agree to edit into a video of the 2017 Psub Regatta. </div><div><br></div><div>I still need to review the data I logged from the trips but the key points were the first ocean side dive was to the coral heads which is 3.9 miles from Doug's house so 7.8 miles total tow with average cabin temp of 93F and RH of 80%. Average speed was about 4.5 MPH. As long as we ran partially submerged to was hot but fine. This was a test dive to see if we could get out deeper. Water was not clear at this location. The deeper dive on Aug 3rd was out to the edge of the deep water. The 7.8 miles from Doug's house (bay side) to the dive site was smooth and we ran submerged so even thought the cabin temp and RH were high, it was not bad at all as it was a smooth tow and there were thinks to see on way out. At the second dive site the water was 100 ft deep and very clear with 4-6 ft swells. Could see the sub on the bottom from the Boston Whaler. The tow back was rough. With 4-6 ft following seas, it was like being on a roller coaster both in the boat and in the sub. Second dive had a total of 15.6 miles of towing at 4.5 MPH, 94F and 84% RH and hatch closed time of around 5 hours. I did not loose my cookies but it was close.<div id="m_-4085103115085192470m_-8590751230032137954m_5961888996869013519gmail-yiv0888986609yui_3_16_0_ym19_1_1502139871792_4063"><br clear="none"></div><div id="m_-4085103115085192470m_-8590751230032137954m_5961888996869013519gmail-yiv0888986609yui_3_16_0_ym19_1_1502139871792_4064" dir="ltr">As Doug noted, the consensus of all was that we need a tender vessel with launch capability to get the subs out to the dive sites without towing. Towing subs sucks. All survived but I used up all my on board water and upon making it back to the beach, consumed several gallon of water. We were all pretty whipped. All in all, it was quite an adventure.</div><div dir="ltr"><br></div><div>More latter.</div><div><br></div><div>Cliff</div><div dir="ltr"><br clear="none"></div><div id="m_-4085103115085192470m_-8590751230032137954m_5961888996869013519gmail-yiv0888986609yui_3_16_0_ym19_1_1502139871792_4201" dir="ltr"> </div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Aug 7, 2017 at 4:53 PM, Douglas Suhr via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.o<wbr>rg</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">Greetings PSUBS group, Douglas Suhr here to share my take on the 4-day<br>
sub operation we just completed in Islamorada, FL (July 31st, August<br>
1-3).<br>
<br>
Wow, what a whirlwind! So July 31st was really an arrival / setup day<br>
with August 1-3 being true operational days. Though it was unfortunate<br>
that Alec wasn't able to make it with Shackleton, we had our hands<br>
full with Cliff's R-300. Without Shackleton, we also had enough time<br>
to get Snoopy set up and lowered into the canal for some basic diving.<br>
<br>
List of Crew: Dan Lance, Steve McQueen, Cliff Redus, Rick Maxwell,<br>
River Dolfi, Mike Patterson, Doug, Sarah, Douglas Suhr.<br>
<br>
This was my first time meeting Dan Lance, a (retired) saturation diver<br>
and commercial welder. What a pleasure to have him join us on this<br>
operation. Dan is modest, but most willing to share his knowledge and<br>
extensive experience with a newbie like me. So pleased to have chatted<br>
with him in the Keys. During the towing of the R-300, Dan manned the<br>
tow line and helped with comms.<br>
<br>
Steve McQueen and River Dolfi did awesome jobs as our frog men.<br>
Filming, attaching / detaching davit and tow lines, etc. they were<br>
both in and out of the water quite a bit (especially Steve). I think<br>
River took a little jelly sting for the team. What troopers!<br>
<br>
Cliff and his assistant Rick are such a joy be around. Rick is one of<br>
the friendliest people you'll ever meet (and even brought a gift for<br>
the group: a watermelon, straight from Texas!). Cliff is always<br>
willing to share his expertise (and sub, too) with anyone who'd like<br>
to learn more. I know that between Dan Lance and Cliff, I learned more<br>
than I can remember last week.<br>
<br>
Mike Patterson, mom, dad and myself were all just providing whatever<br>
kind of "troop support" we could to Cliff and the R-300.<br>
<br>
River, Steve and Myself got in some dive time on Snoopy in the canal<br>
(which was great), but I think the biggest accomplishment was getting<br>
the R-300 out a ways into the ocean.<br>
<br>
Our Boston Whaler (a 25' boat with a single 250hp Yamaha) was able to<br>
tow the R-300 out about 5 miles into the ocean (at about 4mph). We<br>
were in radio communication with Cliff most of the time, though we did<br>
suffer a few intermittent losses in comms. When we got to a spot about<br>
100 feet deep, we started to slow down a bit and at that point the tow<br>
line hook (an admittedly cheap thing) let loose(!) so we decided that<br>
we had reached our dive location. We switched from marine radio to OTS<br>
and Cliff started down. Visibility was supurb! As Cliff neared the<br>
bottom at 100 − 110 feet, he was still quite visible from the Whaler!<br>
His 18 foot long R-300 looked to be about 3 inches long, but wow did<br>
it ever stand out from the rest of the sandy bottom. Cliff spent about<br>
an hour "flying" his sub, surfacing, diving and maneuvering about,<br>
testing systems and observing the ocean around him. By the time Cliff<br>
surfaced and we towed back to port Antigua, elapsed time stood at 4.5<br>
/ 5 hours (estimate). Cliff said that he stayed cool by the water<br>
flowing over the sub's dome hatch while in tow. Upon returning I think<br>
we were all ready to take a break, but everyone felt great<br>
accomplishment with the mission.<br>
<br>
A couple of lessons I took away from the tow out: We need better tow<br>
equipment (better line, hardware and maybe a quick release). Our boat<br>
REALLY needs a GPS (still don't have one). Towing into waves isn't so<br>
much a problem, but when towing with the waves, our tow line needs to<br>
be measured so as to sustain the proper distance between tow vessel<br>
and sub (otherwise the sub and boat are constantly slacking and then<br>
jerking, stressing the tow line and making it difficult for boat and<br>
sub to track straight).<br>
<br>
The devotion of our crew was amazing, even in the heat and the waves<br>
everyone did their jobs. Managing even a small sub operation like this<br>
is more work / effort than meets the eye, that's for sure. At dinner,<br>
one of the main discussions revolved around a support vessel that can<br>
carry a sub or two on board, eliminating the slow, time consuming tow<br>
out to an ocean dive site. Dan Lance shared details on his support<br>
vessel project, which is no doubt going to be a dream in terms of<br>
logistics. Hopefully when said vessel is ready to sail, Dan will lend<br>
its services to host a diving event! ~ Douglas S.<br>
<br>
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