<div dir="ltr">Dave, <div><br></div><div>Thank you for the info as to what happened there in the wireless building. I'm glad there was an exchange and an acknowledgement of the danger. I think we can all agree that safety needs to be the first priority. As for the rest of the questions, I think you and Len have both answered them. The situations are simply too varied to have any good blanket answers. I do think the Massie transmitter and the spark gap demo downstairs in Massie present similar danger. Perhaps we could measure the emf at a certain range, just to have some idea of how they compare. I don't imagine plexiglass presents any barrier at all. If we find that we can detect the EMF on opposite floors of the Massie station, I think we should install a warning light on the opposite floor of when the power supplies are powered on. We should review our procedures as well to ensure the greatest possible safety for all.</div><div><br></div><div>Thanks,</div><div>Randy</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Oct 4, 2022 at 3:53 PM David Caldwell via Thursday <<a href="mailto:thursday@newsm.org">thursday@newsm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif">Besides pacemakers there are now lots of other implanted medical devices that might be affected. I know some of them can be controlled with a magnet, so they are affected by magnetic fields. Some of them stimulate nerves, some release drugs, ... It's not clear that one could ever keep up with testing for all the possible devices that might present problems. Probably best to have general warning signs about implanted medical devices, and have the demonstrator also repeat the warning.</div><div class="gmail_default" style="font-family:verdana,sans-serif"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif">Or do the demos in a Faraday cage, which would add another cool thing to the demo.</div><div class="gmail_default" style="font-family:verdana,sans-serif"><br clear="all"></div><div><div dir="ltr"><span style="color:rgb(102,102,102)"><br>Dave</span><br></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Oct 4, 2022 at 3:40 PM Len Arzoomanian via Thursday <<a href="mailto:thursday@newsm.org" target="_blank">thursday@newsm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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I have a pacemaker and have never been affected by any of the devices mentioned, even if I was running them. I believe it depends on the pacemaker.</div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black"><br></div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black">The lead apron may not work as the pacemaker is usually near the left shoulder and may not cover it.</div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black"><br></div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black">Incidentally when I get my pacemaker checked they tell me if there have been any “incidents” and I have had none ever.</div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black"><br></div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black">That being said the safe bet is to NOT run any of these devices if someone acknowledges they have a pacemaker.</div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black"><br></div><div id="m_8355816842306875690m_467770286878144790338317EditableDivID--xx--yy--42" style="font-family:Verdana;font-size:17px;color:black">Len<br><br>Sent using the mobile mail app<br><br>On 10/4/22 at 3:26 PM, David Crowell via Thursday wrote:
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From: "David Crowell via Thursday" <<a href="mailto:thursday@newsm.org" target="_blank">thursday@newsm.org</a>><br>Date: October 4, 2022<br>To: "Thursday Group" <<a href="mailto:thursday@newsm.org" target="_blank">thursday@newsm.org</a>>,<br>"Randall Snow" <<a href="mailto:pleaseleaveamessage4me@gmail.com" target="_blank">pleaseleaveamessage4me@gmail.com</a>><br>Cc: <br>Subject: Re: [Thursday] Steam Up wrap up - Pacemaker issue
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<div dir="ltr">Randy, <br>
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<div dir="ltr">I've been thinking about the rotary spark gap <span>transmitter </span>demonstrator. <br>
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<div dir="ltr">As usual, I asked if anybody had a Pacemaker. When the gentleman at Steam-up responded he had one, I told the people I couldn't run it. The man said he would move away and walked part way towards the front of the building and he said it was okay. I said are you sure and he said yes. I hit the key a couple of times and he said he felt it, but he was okay. I stopped the demo.<br>
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<div dir="ltr">A few thoughts:</div>
<div dir="ltr">1. Are there any guide lines as to a safe distance? Is the radiation strong enough to go through walls?<br>
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<div dir="ltr">2. Should the power of the spark gap transmitter be decreased? Would this make any difference?<br>
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<div dir="ltr">3. Would it help if the spark gap <span>transmitter </span>were enclosed in a one inch (or more) thick Plexiglas box?</div>
<div dir="ltr">4. Is there a way we can demonstrate the Tesla coil without using the rotary spark gap or is the energy from the <br>
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<div dir="ltr"> Tesla coil itself still a problem? Wikipedia talks about using a solid state device instead of a spark gap.</div>
<div dir="ltr"><a href="https://en.wikipedia.org/wiki/Tesla_coil#Primary_switching" rel="nofollow" target="_blank">https://en.wikipedia.org/wiki/Tesla_coil#Primary_switching</a></div>
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<div dir="ltr"><div>5. Are Pacemakers affected by our Ham Radio transmitter?</div></div>
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<div dir="ltr">6. What about the Massie spark transmitter?
How safe is that as far as a Pacemaker is concerned? Is the radiation
strong enough to affect people downstairs or even outside?<br>
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<div dir="ltr">7.
When the telegraph sounder in the Wireless building is operated, it is
heard in the AK breadboard radio in the other room! I wonder if this can
be a problem for a Pacemaker that is nearby?</div>
<br>
</div></div>Other thoughts:<div dir="ltr">1. When asking if anyone has a Pacemaker, we need to check the other isle by the display cases too.</div>
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<div dir="ltr">2. Maybe we can get a lead apron (like at the dentist office) for a person to wear.</div>
<div dir="ltr">3. To test any of these ideas, a Field Strength Meter or a volunteer with a Pacemaker might be needed!<br>
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<div dir="ltr">4. At least one small child went under the rope in front of the displays. The parent was slow to react.<br>
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<div dir="ltr"><a href="https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker#Magnetic_fields,_MRIs,_and_other_lifestyle_issues" rel="nofollow" target="_blank">https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker#Magnetic_fields,_MRIs,_and_other_lifestyle_issues</a></div>
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<div dir="ltr">Safety must be our highest priority. <br>
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<div dir="ltr">If anyone with a Pacemaker is inside the building, for now just don't operate the transmitter. <br>
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<div dir="ltr">David Crowell</div>
<div dir="ltr">10/04/2022</div>
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On Saturday, October 1, 2022 at 11:54:52 PM EDT, Randall Snow via Thursday <<a href="mailto:thursday@newsm.org" target="_blank">thursday@newsm.org</a>> wrote:
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<div>I want to thank everyone who has contributed to another successful Yankee Steam Up this year. Beyond just the day today, that was of course a bit challenging, I appreciate all the dedication and time through the last month of prep. Our progress is being noticed. I heard numerous comments about the significant work that has taken place in the last few years and nothing but positivity about it all. For a unpredictable dreary day, I don't think we could have asked for a better turnout or more positivity. Thank you all for your help.<div><br></div>
<div>In the way of numbers, we counted about 375 visitors. Given our confinement to covered spaces it still felt busy. Normal numbers would be at least twice that and I expected 3x that for the day. Food sales were strong, hitting 2/3 of the goals on many things and nearly selling out of some too. Again, great considering the day.</div>
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<div>I hope it was a fun day for all of you as well. If there are any stories of particularly good or bad moments, or anything that was noted as needing improvement, please let me know.</div>
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<div>One particularly concerning item came up with a gentleman with a pacemaker who was inside the wireless building during a demonstration of the rotary spark gap transmitter. He overlooked the signs and thought nothing of it until he started feeling the effects. We need to do something more for safety around this circumstance. </div>
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<div>Again, thank you all and please share any thoughts from the day.</div>
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<div>Randy</div>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><font size="4">Randy Snow</font><div><br></div><div><a href="http://www.snowfindings.com" target="_blank">Snow Findings Company</a><br></div><div><a href="http://www.lovements.com" target="_blank">Lovements.com</a><br></div><div><a href="http://www.snowfindings.com/mag-lok" target="_blank">Mag-Lok.com</a><br></div><div><a href="http://www.newsm.org" target="_blank">New England Wireless and Steam Museum</a><br></div><div><br></div></div></div>