HF,VHF,UHF Ham Radio Exposure

Anyone have any data regarding the use of Amateur Radio equipment with an ICD? I have my equipment that can put out 40 - 100 Watts of RF in both CW, digital communication, and various modulations that are common to radio usage.

Some of the bigger radio can push 1500 watts for minutes at a time. If any of this hits the ICD over the "air" what can happen?

Lots of "wives tales" exist but no clear recommendations.

Interesting for us radio geeks .....

Rick KJ4ZIH

4 Comments

Information found so far

by Theknotguy - 2014-12-26 11:12:53

Rick:

I've had discussions about this before on this forum. Most of the information is negative, i.e. we can tell you what didn't happen and you will have to interpolate from there. I haven't been able to find anything where they have done specific research and can give discrete results. I'll discuss EMF, RFI, and self preservation. As you've indicated there are a lot of urban legends, wive's tales, yellow journalism, and just plain misinformation out there. No one really seems to want to discuss facts.

You can go to the search button on the upper right of this forum and search for my post on Hacking Pacemakers. It goes into detail about what is required to hack pacemakers - mostly there isn't information. But I give web addresses on sources of information including the article about hacking pacemakers. If you use critical analysis you'll find out they haven't hacked pacemakers.

I'll give you the Medtronic web address that discusses EMF. Medtronic is conservative in their analysis but since we live in the good ol' US of A where anyone can sue anybody at any time for any thing, I don't blame them for being conservative. In their analysis they suggest you don't get the PM closer than 6 to 12 inches to a running electrical motor. Reading between the lines, that means in most cases you'd almost have to be hugging a running electrical motor before it would affect a PM. I don't think anyone will be hugging a running vacuum sweeper in the near future.

Along the same lines I volunteer in a woodshop. I'm around all sorts of electric motors. The largest are 220 volt motors used on the table saws. The closest I've been is 3 feet to a 220 volt motor at startup when it pulls the most current and puts out the largest EMF field. Absolutely no problems. So I'm well outside the 6-12 inch range suggested by Medtronic and I've had no problems. While some people have considered my intelligence to be lacking, even I am not going to be hugging a 220 volt electric motor on a running table saw. I may be on a first name basis with the local ER, but I don't want the doctors to be saying, "Guess what that chuckle head did THIS time!!!" Self preservation does kick in.

My son called and asked if I could jump start my daughter-in-law's car during a cold snap last year. Completely forgot about my PM and was leaning over two different running engines with alternators cranking. No problem. Once again, I was, at the closest, about 2 feet away from a running alternator when it was cranking and supplying juice for two cars. So I was well outside the limits suggested by Medtronic. However, I'm not going to go out and get a job at AAA jump starting cars. These were a GM and Honda America cars with good equipment. If you had a rice car, or one of those Found On Road Dead cars, I don't know if you'd get the same results. Like I said, brain was temporarily shut off and I got away with it.

At the charity where I volunteer, I regularly pass within 1000 feet of two broadcasting TV towers. Both broadcast at a 60 mile radius, line-of-sight, so you know they're broadcasting thousands of watts of RFI. When I was installing computer networks, any time we were in the area, it was fun to take a terminal out of the box and set it up. You'd get sea shore "waves" on the screen from the RFI being broadcast from the TV towers, so I know there was some heavy RFI. Like I said, have passed within a 1000 feet of the broadcasting towers with absolutely no problems with my PM. That's with the window down, arm resting on the door, so I know I'm getting blasted with whatever is being broadcast. No problems.

In the posting on hacking pacemakers, a study done by that State up north - i.e. University of Michigan, they indicated you could cause problems with an EXTERNAL device at 2 to 3 meters. (That's approximately 7 to 10 feet.) They indicated you had to be 2 to 3 centimeters away from an INTERNAL device in order to cause problems. (That's 3/4" to about 1".) They didn't specify wattage or devices used. But I'd guess it had to be pretty substantial.

So, for you, that means you'd have to hook up your radio, attach a broadcasting antenna, hold the emitting end directly over your PM and punch the transmit button. I think the part of your brain that takes care of self preservation would balk at trying that experiment. So if your broadcasting tower is on your roof, even if you are in a second story room, I don't think you'd be getting anywhere near the wattage being put out by the TV towers. Interpolation on my part is that you're nowhere near any RFI that could bother your PM. Oh, and I've got a guy two houses down from mine with the big towers. He's broadcasting all the time and I've never had any problems. And that's with me being outside with the antennas emitting the full blast RFI. No problems.

Past posts on this forum from radio guys have been answered but we've never gotten a return message from the people posting. I'd have to assume from that, 1) the people are dead or, 2) they haven't had any problems and haven't bothered to tell us. We also had a radio tech working on airplanes who said he hasn't had any problems. But there you're working with closed systems, i.e. you're inside a closed cockpit with aluminum skin around you. So I don't know how much direct wattage he's getting. Even then, he said he steers clear of the running jet engines because of the EMF being put out by the generators. Hasn't had any problems but doesn't want to temp fate. Don't blame him.

I was able to travel from the US to the UK this year. Went through airport screening without any problems. Had a guy sneak up on me in the UK and use one of those security wands. Finally had to go through a metal detector at, of all places, the State Fair. No problems with my PM. We did have one member on the forum who said her PM, installed in 2008 did set off some security alarms. My PM was installed in 2013 and I haven't had any problems. So the newer PM's may be better shielded than previous models.

Finally, PM's when they do get into an EMF or RFI field that disturbs them are supposed to go into a test or maintenance mode. That means I would feel the same thing I do when they do a reading on my PM. So that would be a warning that something wasn't right. Medtronic says to back out of the area and the PM is supposed to reset itself and go back to its programming. For me that means my PM would drop to 60BPM. So far I've never had that happen. So even if you do get into an EMF or RFI field, you won't just drop dead, you will get some warning.

One other caveat. You have an ICD which is different from a PM. Since I have a PM all my observations have been based upon that. My PM is MRI approved and supposedly no ICD's are approved for MRI's at this time. There may be some differences but even then, I don't think they'd want ICD's being kicked off by just any stray EMF or RFI fields.

Two additional things. 1) visit a fellow radio person and have them do their thing. That way you'd have someone around in case something went wrong. 2) Send a letter to your radio trade magazine or post an email with your radio club online and ask for comments from other radio guys who have PM's or ICD's. You'll probably get some good responses from them.

Hope this gives you some information with which to work. Hope you'll come back and tell us what you've found. Would be nice to get some good, solid facts instead of the misinformation we've gotten so far.

http://www.medtronic.com/wcm/groups/mdtcom_sg/@mdt/@crdm/documents/documents/electromagnetic-compatibility.pdf



Hey knotguy, some of us are radio GALS.. heh heh heh

by Griddlebone - 2014-12-29 01:12:51

The St. Jude tech told me that I shouldn't have any problem running 100W. He didn't go higher than that because that's what I run - 5W to 100W. He said maybe I'd want to think about it before becoming the type of DX ham whose roof looks like an antenna farm, blasting 1500W to Heard Island. The place I worry about 1500W is transmitting, not receiving from someone who's running a high power station.

The sphere of influence of radiowave energy is in the vicinity of the transmitting antenna, not the receiver.

My doc said to use a simple test: If I'm on the air and start feeling "funny", move about 5 feet away from the shack. If I feel better, think about changing whatever I was doing with the radio.

On that basis, I went to Pacificon this year. I didn't volunteer to work W100AW/6 which was set up in a tent under an antenna tower but I walked through there a lot because our RV was parked behind it. I was in the RV for up to 2 hours at a time with no "funny" feelings.

Like TKG, I have a PM, not an ICD, so I can only comment on my personal experiences with a PM.

If you search for ICD on the ARRL.org web site, you'll find several articles on this topic. Try this link for links to several of them: http://www.arrl.org/pacemaker

73

check ARRL

by bznavyveteran - 2015-01-20 10:01:56

Check out the info at www.arrl.org/pacemaker

I can't compare with those responses...

by mtaylor - 2015-03-15 12:03:15

,but in my experience so far, it's not an issue.

Hope to hear you on the air!

-VE6FTR

You know you're wired when...

You have a maintenance schedule just like your car.

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