Re: HF Magnetic Loop and Pacemaker

Jim Sheldon

Morbidly funny John, but really, a good point.  Some info on at least one brand of pacemaker (the one I have).

I too have a pacemaker.  I often run 500 watts and one end of the 160-80-40 meter antenna runs right over the shack, about 3 feet above the house roof.  My pacemaker is from "Boston Scientific", has bluetooth connectivity to a remote monitor that lets my cardiologist know immediately if something goes wrong with either ME or the pacemaker.  I'm on the air almost daily for at least one QRO contact on 40 meters and in over 12 years, have had no RF episodes with the pacemaker.

My Boston Scientific rep said the main thing to avoid is high magnetic fields as a coded magnetic signal is used to trigger diagnostic mode in their pacemakers so a Mag Loop might be a different ball game entirely.  I don't have one here but then I have a 40' telescoping vertical that collapses down to 3 feet for my portable operations when I even go portable anymore - LOL.

That being said, I agree with the need to use CAUTION when operating close to radiated fields of any kind when one has a pacemaker implant as I'm sure the manufacturers all use different RF and Magnetic exposure standards from each other and results will surely vary.  Best to err on the side of safety.

Jim, W0EB

------ Original Message ------
From: "John Lonigro" <jonigro@...>
Sent: 1/30/2020 9:42:39 AM
Subject: Re: [4SQRP] HF Magnetic Loop and Pacemaker

Start with 1 Watt, then go with 2 Watts, etc.  If you die, back down a Watt (hi).

John, AA0VE

On 1/30/20 9:24 AM, John - KK4ITX via Groups.Io wrote:
I use the MFJ-9232 QRP Pocket Loop tuner and find it a useful setup to eliminate the local noise.  There are several YouTube videos showing good results but beware...... they were made when there were sun spots.  I had great fun rigging up the expansion arrangement to allow for various lengths of wire.  To get a broader bandwidth I used trailer hookup wire, seems to work better than the wire that came with it.

The supports are driveway markers and I really lucked out at a Flea Market with the $4.00 heavy duty tri-pod.  I have attached a picture of the assembled unit if anyone is interested I have more and some additional hints and details to offer.

As for use with a pacemaker ?  You will know if it is bothering you or anyone else I believe.  When I tune up I am listening (RX) or using my Sark 100 so there’s no large amount of RF present....... Operating (TX) one would be several feet away so at 5w I doubt that you would be affected but just go at it slow (1-2w) and see what happens.



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On Jan 29, 2020, at 22:18, Dan Reynolds <on30ng@...> wrote:

I have access to some hardline and I'm thinking about making  a transmitting loop. I know there was a design out there that used an Arudino to tune the loop at frequency changes... 
Anybody have some decent designs - I do not want to design it myself. I'm not too proud to borrow someone else's work. 

Also, does anyone know about any problems with a transmitting mag loop and a pacemaker (QRP levels only). 

Dan Reynolds -- KB9JLO

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