On 5/22/2013 1:13 AM, David Ryeburn wrote:
In article ,
"Irv Finkleman" wrote:

I've had a pacemaker for years and have operated using open wire feeder, and
often end fed antennas with a counterpoise ground in my suite. Never had a
problem. From what I understand, most pacemakers will not be bothered, and
if they are,
you would soon feel the difference -- quick enough to key up. At QRP levels
it's
highly unlikely you will notice anything.

That's good to know. But I'd still be worried. I'd hate to be 10 km up a
steep trail and after supper find that my pacemaker was acting up when I
fired up the rig.

In article , John S
wrote:

How many V/M can your pacemaker tolerate?

I have no idea. And I suspect if I asked my cardiologist he'd ask "why
do you want to know" and if I told him I wanted to operate a ham radio
transmitter while many km away from other people up in the mountains,
he'd just say "don't do that".

Anyway, I'd still like to know how well or how badly my triangular
antenna idea (closed loop for 40, 20, 15, or 10 and open loop for 80 or
30) would work. I'll probably get an Elecraft KX3 which has a very wide
range antenna tuner option, so I'm sure it would match such an antenna
system, but I wonder how much stress would be put on the current balun,
and what sort of patterns I'd get on the different bands. The latter
might have some influence on how I oriented the antenna at installation,
assuming there were enough trees around that I'd have a choice. I
suspect it's a pretty good, and certainly simple, multi-band antenna
setup, with relatively low feedpoint impedance on all bands, but it
would be nice to know that I'm right about that.

David, who just found out that he's now VE7EZM

I am a loop fanboy. I admit it. I do not know how well you triangular
loop would work. I have only used horizontal 4 point square loops.
However, I would advise that it seems to me to not make enough sense to
be using a loop out in the wilderness. I only use a loop because I live
right in the middle of town and I need to suppress the local qrn. There
is plenty of it. I would think that a dipole fed with coax or open wire
line (for multi-band use) would work just as well.

If you are able to feel your heartbeat and can tell if there is some
sort of problem with the key down, of course you know that your
pacemaker is sensitive to RFI. My own heart was exposed to 20,000 volts
with RF riding on it when I was young. I have always been able to feel
my own heart beat after that event. BTW, it took me a year to recover
from this exposure to high voltage. The good news is that I can tell
whenever I am doing something that is effecting my heart rate or rhythm.
This is pretty important when trying a new drug.

I also think that running much power where you cannot call an ambulance
might be a risky thing to do. If you are the only who would be effected
by your death, than you have the right to experiment. If you are married
and have children, I believe you must consider their welfare. None of us
has the right to be cavalier with our safety if our death would
negatively impact someone. Just my opinion of course.

Michael

On Thursday, May 23, 2013 12:10:54 PM UTC-5, seediq wrote:
None of us

has the right to be cavalier with our safety if our death would

negatively impact someone. Just my opinion of course.



Michael

I can "feel" when I'm in a high RF environment. And I seem
to be effected more by lower frequencies, than I do high.
I've "felt" RF at home once when running 160 meters with
a antenna fed from the shack.
And I've also felt it when running mobile, with the antenna
behind my head on the trunk lid. This was noticed when
running CW on I think 80m if I remember right.
And I have no pacemaker, etc, and was in normal health.
I didn't feel pain per say. It made me feel nervous and
uneasy. Hard to explain really.. But it definitely would
start and stop with my sending. It took a while before
I realized what was happening, and then I tested it with
sending tests. Sure nuff, every time I would start sending,
I would start feeling the effects. Quit sending, and it would
go away.
This was with a plastic bugcatcher mounted on the trunk
lid, with the loading coil just above roof level.
Running 100w CW. I've never really noticed it using SSB.
Too sporadic I expect, where as CW is pretty much pedal
to the metal when actually transmitting.

In both cases, I was near the current maximum. At my
table in the 160m case, and beaming the back of my head
in the car.
But I don't see this as being much of an issue with QRP.
Particularly if the feed line is decoupled, and the
actual antenna is a good bit away from the operator.

On 5/23/2013 2:28 PM, wrote:
On Thursday, May 23, 2013 12:10:54 PM UTC-5, seediq wrote:
None of us

has the right to be cavalier with our safety if our death would

negatively impact someone. Just my opinion of course.



Michael

I can "feel" when I'm in a high RF environment. And I seem
to be effected more by lower frequencies, than I do high.
I've "felt" RF at home once when running 160 meters with
a antenna fed from the shack.
And I've also felt it when running mobile, with the antenna
behind my head on the trunk lid. This was noticed when
running CW on I think 80m if I remember right.
And I have no pacemaker, etc, and was in normal health.
I didn't feel pain per say. It made me feel nervous and
uneasy. Hard to explain really.. But it definitely would
start and stop with my sending. It took a while before
I realized what was happening, and then I tested it with
sending tests. Sure nuff, every time I would start sending,
I would start feeling the effects. Quit sending, and it would
go away.
This was with a plastic bugcatcher mounted on the trunk
lid, with the loading coil just above roof level.
Running 100w CW. I've never really noticed it using SSB.
Too sporadic I expect, where as CW is pretty much pedal
to the metal when actually transmitting.

In both cases, I was near the current maximum. At my
table in the 160m case, and beaming the back of my head
in the car.
But I don't see this as being much of an issue with QRP.
Particularly if the feed line is decoupled, and the
actual antenna is a good bit away from the operator.


I think you are particularly sensitive to RF. We are all different. I
would be very cautious with RF if I were you. I have found from
experience that the lower the frequency, like 160 meters, the more
penetrating power it has to get into a house or car. I do not understand
the mechanism but I sure know this from experience.

Yes, I would expect qrp operation to not be a problem. I run 1200 watts
most days with a loop surrounding my home. I get away with it. There are
studies that show that active ham radio operators do not live as long as
those who are not. They often implicate rf exposure. I personally
believe it is actually because it is such a sedentary hobby. We have to
get out and walk each day and do our treadmill to keep our heart healthy.

On 5/24/2013 1:34 PM, seediq wrote:
I think you are particularly sensitive to RF. We are all different. I
would be very cautious with RF if I were you. I have found from
experience that the lower the frequency, like 160 meters, the more
penetrating power it has to get into a house or car. I do not understand
the mechanism but I sure know this from experience.

Yes, I would expect qrp operation to not be a problem. I run 1200 watts
most days with a loop surrounding my home. I get away with it. There are
studies that show that active ham radio operators do not live as long as
those who are not. They often implicate rf exposure. I personally
believe it is actually because it is such a sedentary hobby. We have to
get out and walk each day and do our treadmill to keep our heart healthy.

Slightly off topic.

Or maybe it's because of exposure to vaporized tin/lead solder.

We are electronic hobbyists, or some of us are.

tom
K0TAR

wrote in message
...

I can "feel" when I'm in a high RF environment. And I seem
to be effected more by lower frequencies, than I do high.
I've "felt" RF at home once when running 160 meters with
a antenna fed from the shack.
And I've also felt it when running mobile, with the antenna
behind my head on the trunk lid. This was noticed when
running CW on I think 80m if I remember right.
And I have no pacemaker, etc, and was in normal health.
I didn't feel pain per say. It made me feel nervous and
uneasy. Hard to explain really.. But it definitely would
start and stop with my sending. It took a while before
I realized what was happening, and then I tested it with
sending tests. Sure nuff, every time I would start sending,
I would start feeling the effects. Quit sending, and it would
go away.
This was with a plastic bugcatcher mounted on the trunk
lid, with the loading coil just above roof level.
Running 100w CW. I've never really noticed it using SSB.
Too sporadic I expect, where as CW is pretty much pedal
to the metal when actually transmitting.

In both cases, I was near the current maximum. At my
table in the 160m case, and beaming the back of my head
in the car.

I'm sensitive to static charges ... at least I think so. In 1972, I
taught a course for technicians working on high-speed Xerox
Telecopiers, a run-up to todays FAX machines. It was called
LDX, which stood for Long-Distance Xerography.

When I was around those machines, which used multiple
static charges to form the images, I was always nervous,
anxious and jumpy. I recall an odd smell, similar to the air
before a thunderstorm. (ozone?) I never had the same
feelings in the classroom, so I'm fairly sure it was the
effect of those machines.

"Sal"

"seediq" wrote in message
...

On 5/22/2013 1:13 AM, David Ryeburn wrote:
In article ,
"Irv Finkleman" wrote:

I've had a pacemaker for years and have operated using open wire feeder,
and
often end fed antennas with a counterpoise ground in my suite. Never had
a
problem. From what I understand, most pacemakers will not be bothered,
and
if they are,
you would soon feel the difference -- quick enough to key up. At QRP
levels
it's
highly unlikely you will notice anything.

That's good to know. But I'd still be worried. I'd hate to be 10 km up a
steep trail and after supper find that my pacemaker was acting up when I
fired up the rig.

In article , John S
wrote:

How many V/M can your pacemaker tolerate?

I have no idea. And I suspect if I asked my cardiologist he'd ask "why
do you want to know" and if I told him I wanted to operate a ham radio
transmitter while many km away from other people up in the mountains,
he'd just say "don't do that".

Anyway, I'd still like to know how well or how badly my triangular
antenna idea (closed loop for 40, 20, 15, or 10 and open loop for 80 or
30) would work. I'll probably get an Elecraft KX3 which has a very wide
range antenna tuner option, so I'm sure it would match such an antenna
system, but I wonder how much stress would be put on the current balun,
and what sort of patterns I'd get on the different bands. The latter
might have some influence on how I oriented the antenna at installation,
assuming there were enough trees around that I'd have a choice. I
suspect it's a pretty good, and certainly simple, multi-band antenna
setup, with relatively low feedpoint impedance on all bands, but it
would be nice to know that I'm right about that.

David, who just found out that he's now VE7EZM

# I am a loop fanboy. I admit it. I do not know how well you triangular
# loop would work. I have only used horizontal 4 point square loops.
# However, I would advise that it seems to me to not make enough sense to
# be using a loop out in the wilderness. I only use a loop because I live
# right in the middle of town and I need to suppress the local qrn. There
# is plenty of it. I would think that a dipole fed with coax or open wire
# line (for multi-band use) would work just as well.

# If you are able to feel your heartbeat and can tell if there is some
# sort of problem with the key down, of course you know that your
# pacemaker is sensitive to RFI. My own heart was exposed to 20,000 volts
# with RF riding on it when I was young. I have always been able to feel
# my own heart beat after that event. BTW, it took me a year to recover
# from this exposure to high voltage. The good news is that I can tell
# whenever I am doing something that is effecting my heart rate or rhythm.
# This is pretty important when trying a new drug.

# I also think that running much power where you cannot call an ambulance
# might be a risky thing to do. If you are the only who would be effected
# by your death, than you have the right to experiment. If you are married
# and have children, I believe you must consider their welfare. None of us
# has the right to be cavalier with our safety if our death would
# negatively impact someone. Just my opinion of course.

Wow....what a bunch of old farts
Looks like everybody on this group has a pacemaker.

I haven't had any issues with mine from airport stuff, HF, VHF, etc. I
haven't experimented with magnets or appreciable microwave energy though.

The only time I can fell the pacemaker action is during the periodic checks
when the doc speeds it up or slows it down.

My concern from RF energy would be if noise got introduced that ended up
changing the programmable setting.

So far, so good, but I'm only a couple of years into using mine. However, I
had imagined that it would be more delicate than has turned out to be the
case.