Nearly five years ago, I had a pacemaker installed and also had concerns
about RFI. My pacemaker was set to be on constantly rather than on-line. I
asked on several reflectors about possible interference and received
messages from a number of users who had had no problem. Only one responder
had had a problem and that was with a much older pacemaker. I also had long
talks with engineers at the manufacturer ( Joe Ferris in Tech Services at
St. Jude). With some trepidation, I resumed ham operation on 160 to 6M
using CW, a KW and wire antennas with fairly high SWR, e.g. 1.5:1 to 2.0:1.
I also started wearing a Fitbit so I could monitor the pulse rate. As far
as I can see, I have had no problems with RFI over that five year period. I
suggest you contact the manufacturer to obtain info on your particular
device.
73,
Dennis, K2SX
-----Original Message-----
From: Topband <topband-bounces+dbmcalpine73=gmail.com@contesting.com> On
Behalf Of topband-request@contesting.com
Sent: Monday, March 9, 2020 12:00 PM
To: topband@contesting.com
Subject: Topband Digest, Vol 207, Issue 10
Send Topband mailing list submissions to
topband@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/topband
or, via email, send a message with subject or body 'help' to
topband-request@contesting.com
You can reach the person managing the list at
topband-owner@contesting.com
When replying, please edit your Subject line so it is more specific than
"Re: Contents of Topband digest..."
Today's Topics:
1. Re: RF Issues with Heart Pacemakers (Jim Brown)
2. Re: RF Issues with Heart Pacemakers (Bill Weaver)
3. Fwd: RF Issues with Heart Pacemakers (Mpridesti)
4. Re: RF Issues with Heart Pacemakers (Charles Otnott)
5. RBN and cluster spots (VE6WZ_Steve)
6. Re: RBN and cluster spots (daraymond@iowatelecom.net)
7. Re: RBN and cluster spots (VE6WZ_Steve)
8. Re: RBN and cluster spots (Mike Smith VE9AA)
9. Re: Inverted L with elevated radials for topband (Jeff Blaine)
10. Re: RBN and cluster spots (W0MU Mike Fatchett)
----------------------------------------------------------------------
Message: 1
Date: Sun, 8 Mar 2020 11:11:39 -0700
From: Jim Brown <jim@audiosystemsgroup.com>
To: topband@contesting.com
Subject: Re: Topband: RF Issues with Heart Pacemakers
Message-ID:
<8a96737f-51c7-46c0-b501-cbafdc1541c5@audiosystemsgroup.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Hi George,
Many years ago, I saw what I considered solid input that these devices are
not sensitive to RF at frequencies we use. The laws of physics support that
-- RFI is coupled either by by antenna action or a magnetic field. Devices
like this are far too small for there to me much of either, and proper
design requires that their construction reject both means of coupling by
their construction.
73, Jim K9YC
On 3/8/2020 7:24 AM, George Taft via Topband wrote:
> Is there anyone on the TB reflector with experience with this new
pacemaker device?
------------------------------
Message: 2
Date: Sun, 08 Mar 2020 14:22:26 -0400
From: Bill Weaver <weaverwf@usermail.com>
Cc: topband@contesting.com
Subject: Re: Topband: RF Issues with Heart Pacemakers
Message-ID: <577cb781-4118-4c89-ab56-a4edd16fb6a9@usermail.com>
Content-Type: text/plain; charset=UTF-8
I worked in engineering for a pacemaker firm for 16 years. About a half
dozen of the other engineers were hams too. I never heard of any issues with
RF interference (and I surely would have being right in the middle of it).
I'm talking about 1990's technology as I have been retired for 20 years.
73,
Bill WE5P
?Get BlueMail for Android ?
On Mar 8, 2020, 14:11, at 14:11, Jim Brown <jim@audiosystemsgroup.com>
wrote:
>Hi George,
>
>Many years ago, I saw what I considered solid input that these devices
>are not sensitive to RF at frequencies we use. The laws of physics
>support that -- RFI is coupled either by by antenna action or a
>magnetic field. Devices like this are far too small for there to me
>much of either, and proper design requires that their construction
>reject both means of coupling by their construction.
>
>73, Jim K9YC
>
>On 3/8/2020 7:24 AM, George Taft via Topband wrote:
>> Is there anyone on the TB reflector with experience with this new
>pacemaker device?
>
>_________________
>Searchable Archives: http://www.contesting.com/_topband - Topband
>Reflector
------------------------------
Message: 3
Date: Sun, 8 Mar 2020 15:38:25 -0400
From: Mpridesti <mpridesti@yahoo.com>
To: topband <topband@contesting.com>
Subject: Topband: Fwd: RF Issues with Heart Pacemakers
Message-ID: <8E124F4F-BED1-4DE0-9A45-41A0CD649325@yahoo.com>
Content-Type: text/plain; charset=utf-8
?Hi George
>
> Several years ago my XYL went through the same and had a pacemaker put in.
At the time, I was seriously into contesting and at one time I had multiple
stations in a multi multi setup. During that time I had concerns too and
invited the Medtronics tech to my house to confirm no issues. Amazingly my
wife was ok doing what I considered a worse case test. Fired up 4 stations,
1500 watts each, with what yagis were in play, all pointed to the house.
Thought I might affect the laptop/sensing unit from the tech but no. Not a
single issue with anything (Good!). Closest tower was 100 ft away.
>
> Not sure if it?s exactly the same unit but the Medtronics stuff excellent
in this environment. I don?t think you will have any problems.
>
> Regards,
>
> Mark, K1RX
>
>
>> On Mar 8, 2020, at 10:24 AM, George Taft via Topband
<topband@contesting.com> wrote:
>>
>> ?A few years ago, my Cardiologist was recommending a pacemaker for my
heart health. I was concerned over RF issues with my DX operating and
polled the TB reflector for personal reports from those who current had
pacemakers installed. I got several encouraging reports, but at that time
my heart health was stable and I opted not to have it done.
>>
>> I currently suffer from A-fib and the condition is worse than that
previous period. My Cardiologist is now recommending a new pacemaker
device: Medtronics Micra. It is installed directly into a heart chamber
and has a supposedly battery life of ten years or more. My specialist says
there is no danger from RF issues with the "Micra" implant.
>>
>> I mostly operate low bands on my two phased arrays which are some
distance (400 - 500 ft) from my shack. And of course I use an Amp with
output of 1000-1500 w.
>>
>> Is there anyone on the TB reflector with experience with this new
>> pacemaker device? I would appreciate comments either on or off line,
>> thanks
>>
>> 73 George W8UVZ
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband
>> Reflector
------------------------------
Message: 4
Date: Sun, 8 Mar 2020 15:06:22 -0500 (GMT-05:00)
From: Charles Otnott <wd5bjt@peoplepc.com>
To: jim@audiosystemsgroup.com, topband@contesting.com
Subject: Re: Topband: RF Issues with Heart Pacemakers
Message-ID:
<1773418714.3011.1583697982365@wamui-moana.atl.sa.earthlink.net>
Content-Type: text/plain; charset=UTF-8
George, et.al.,
Several years ago I had an implant as part of a heart study. My first
question to the cardiologist was "what about 2Kw SW & VHF-UHF transmitters?"
His answer was "These newer devices are immune to high powered ham radios."
He did not know that I was a ham. I went back to blasting on the air-waves
without any issues.
I was so interested in the thumb-drive sized device, when it came time to
remove it after 5 years, he gave it to me and it sets on my operating desk
as a reminder.
Good luck with your implant. Blast away.
73 & Best DX
Charlie
WD5BJT
See September 2006 CQ Magazine for a published work.
www.qsl.net/wd5bjt
-----Original Message-----
>From: Jim Brown <jim@audiosystemsgroup.com>
>Sent: Mar 8, 2020 1:11 PM
>To: topband@contesting.com
>Subject: Re: Topband: RF Issues with Heart Pacemakers
>
>Hi George,
>
>Many years ago, I saw what I considered solid input that these devices
>are not sensitive to RF at frequencies we use. The laws of physics
>support that -- RFI is coupled either by by antenna action or a
>magnetic field. Devices like this are far too small for there to me
>much of either, and proper design requires that their construction
>reject both means of coupling by their construction.
>
>73, Jim K9YC
>
>On 3/8/2020 7:24 AM, George Taft via Topband wrote:
>> Is there anyone on the TB reflector with experience with this new
pacemaker device?
>
>_________________
>Searchable Archives: http://www.contesting.com/_topband - Topband
>Reflector
------------------------------
Message: 5
Date: Sun, 8 Mar 2020 15:15:46 -0600
From: VE6WZ_Steve <ve6wz@shaw.ca>
To: Topband <topband@contesting.com>
Subject: Topband: RBN and cluster spots
Message-ID: <F86621DE-1EA6-4F21-B0A7-91AB738008CB@shaw.ca>
Content-Type: text/plain; charset=utf-8
This winter I've noticed that when CQing on 160m, if I get spotted on the
?conventional? packet cluster, I seem to get more action.
I?ve always found this surprising because usually with 3 seconds (!!!) my
call is spotted on the RBN network, so why doesn't everyone already know I?m
CQing there?
It seems that quite a few ops out there either don?t know about, have
forgotten about, or somehow ?don?t believe? in the RBN network?? As far as
thinking the RBN network is ?un-fair? or not "old school" like finding your
own DX, well to each his own, but the packet cluster ship sailed many years
ago!
Perhaps this email is just a reminder to consider either checking the RBN
network directly in your browser or getting the RBN skimmer spots fed
directly into your logging program packet window.
I use the VE7CC ?CC cluster? program which will filter the skimmer spots
anyway I want (eg. no NA spots) and they get streamed together with the
conventional packet cluster into my logging program, and also directly onto
the Flex waterfall. If anyone in EU calls CQ, the spot will show up on the
waterfall within 2-5 seconds! I know exactly where the ?open? spots are on
160m before I call CQ. I see the who?s-who across the band all the time.
I know many reading this already use the RBN regularly, but even in the KST
chat room I get questions like ?where are you CQing?? Heck, I was spotted
within seconds of my first CQ on the RBN network !
73, de steve ve6wz
------------------------------
Message: 6
Date: Sun, 8 Mar 2020 16:51:27 -0500
From: <daraymond@iowatelecom.net>
To: "VE6WZ_Steve" <ve6wz@shaw.ca>, "Topband" <topband@contesting.com>
Subject: Re: Topband: RBN and cluster spots
Message-ID: <A349FD9C3CD14765850D451B060A7491@DavidBrentPC>
Content-Type: text/plain; format=flowed; charset="utf-8";
reply-type=original
While I watch RBN I still watch the old fashioned packet cluster that whose
ship sailed many years ago. Many worthwhile things appear on the cluster
that never appear on RBN. If you really want to know what's going on you
need to be watching both. 73. . .Dave, FLS
-----Original Message-----
From: VE6WZ_Steve
Sent: Sunday, March 08, 2020 4:15 PM
To: Topband
Subject: Topband: RBN and cluster spots
This winter I've noticed that when CQing on 160m, if I get spotted on the
?conventional? packet cluster, I seem to get more action.
I?ve always found this surprising because usually with 3 seconds (!!!) my
call is spotted on the RBN network, so why doesn't everyone already know I?m
CQing there?
It seems that quite a few ops out there either don?t know about, have
forgotten about, or somehow ?don?t believe? in the RBN network?? As far as
thinking the RBN network is ?un-fair? or not "old school" like finding your
own DX, well to each his own, but the packet cluster ship sailed many years
ago!
Perhaps this email is just a reminder to consider either checking the RBN
network directly in your browser or getting the RBN skimmer spots fed
directly into your logging program packet window.
I use the VE7CC ?CC cluster? program which will filter the skimmer spots
anyway I want (eg. no NA spots) and they get streamed together with the
conventional packet cluster into my logging program, and also directly onto
the Flex waterfall. If anyone in EU calls CQ, the spot will show up on the
waterfall within 2-5 seconds! I know exactly where the ?open? spots are on
160m before I call CQ. I see the who?s-who across the band all the time.
I know many reading this already use the RBN regularly, but even in the KST
chat room I get questions like ?where are you CQing?? Heck, I was spotted
within seconds of my first CQ on the RBN network !
73, de steve ve6wz
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
------------------------------
Message: 7
Date: Sun, 8 Mar 2020 16:03:19 -0600
From: VE6WZ_Steve <ve6wz@shaw.ca>
To: daraymond@iowatelecom.net
Cc: Topband <topband@contesting.com>
Subject: Re: Topband: RBN and cluster spots
Message-ID: <AB902872-17C7-495A-BFCD-AA0D501C7C75@shaw.ca>
Content-Type: text/plain; charset=utf-8
Dave,
I agree entirely.
Which is why I have BOTH streamed together via VE7CC into my main packet
window, the bandmap, and onto the Flex waterfall.
steve
> On Mar 8, 2020, at 3:51 PM, <daraymond@iowatelecom.net>
<daraymond@iowatelecom.net> wrote:
>
> While I watch RBN I still watch the old fashioned packet cluster that
whose ship sailed many years ago. Many worthwhile things appear on the
cluster that never appear on RBN. If you really want to know what's going
on you need to be watching both. 73. . .Dave, FLS
>
> -----Original Message----- From: VE6WZ_Steve
> Sent: Sunday, March 08, 2020 4:15 PM
> To: Topband
> Subject: Topband: RBN and cluster spots
>
> This winter I've noticed that when CQing on 160m, if I get spotted on the
?conventional? packet cluster, I seem to get more action.
> I?ve always found this surprising because usually with 3 seconds (!!!) my
call is spotted on the RBN network, so why doesn't everyone already know I?m
CQing there?
>
> It seems that quite a few ops out there either don?t know about, have
forgotten about, or somehow ?don?t believe? in the RBN network?? As far as
thinking the RBN network is ?un-fair? or not "old school" like finding your
own DX, well to each his own, but the packet cluster ship sailed many years
ago!
>
> Perhaps this email is just a reminder to consider either checking the RBN
network directly in your browser or getting the RBN skimmer spots fed
directly into your logging program packet window.
> I use the VE7CC ?CC cluster? program which will filter the skimmer spots
anyway I want (eg. no NA spots) and they get streamed together with the
conventional packet cluster into my logging program, and also directly onto
the Flex waterfall. If anyone in EU calls CQ, the spot will show up on the
waterfall within 2-5 seconds! I know exactly where the ?open? spots are on
160m before I call CQ. I see the who?s-who across the band all the time.
>
> I know many reading this already use the RBN regularly, but even in the
KST chat room I get questions like ?where are you CQing?? Heck, I was
spotted within seconds of my first CQ on the RBN network !
>
> 73, de steve ve6wz
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
------------------------------
Message: 8
Date: Sun, 8 Mar 2020 20:01:08 -0300
From: "Mike Smith VE9AA" <ve9aa@nbnet.nb.ca>
To: <topband@contesting.com>
Subject: Re: Topband: RBN and cluster spots
Message-ID: <004001d5f59d$749f1170$5ddd3450$@nbnet.nb.ca>
Content-Type: text/plain; charset="us-ascii"
Steve,
I wish I knew the answer to your question. When I go assisted in contests,
(which is probably only 20-30% of the time)
I connect to VE7CC which carries RBN spots. ( I prefer to tune for my DX,
but that's another story)...I will go assisted if the sponsor does not
differentiate between assisted and non-assisted..why would I want to tie
1-arm behind my back if there is no separate category?HI
I don't know which clusters carry them in EU (or if EU's connect to VE7CC as
well) but I *can* tell you that after only a couple CQ's in any big CW
contest, I have the same hoard of EU big guns (mostly M/M's) call me, so
that tells me it's (probably) an RBN spot.
Then later, at other times things will be very dry for a long time and then
I'll get a little mini "packet pileup" of normally weaker stns when
apparently some kind soul has spotted me on a traditional
Telnet/Packetcluster there in EU..often it's a flurry of mostly DL's, or
mostly PA's, or mostly EA's (you get the idea)
Because I normally run UNassisted, after every contest I'll do a search on
dxscape or oh8x cluster to see who the kind souls were that spotted me and
whether it coincided with the mini packet pileups and it almost always is.
Most times it's callsigns I don't readily recognize and they are not the big
guns (who use the RBN_). I am always grateful we have both, but scratch my
head why someone would only want 4cylinders naturally aspirated, when they
can have 8 or 12 turbocharged!
Seems sooooo easy to me. Connect to a cluster which carries RBN spots.
Easy-Peasy.
For reasons that I am not privy to, I still don't think many in EU do.
Weird !
Mike VE9AA..'course the RBN didn't help me at all this weekend on SSB, hi !
VE6WZ sez:
".It seems that quite a few ops out there either don't know about, have
forgotten
about, or somehow "don't believe" in the RBN network?? ."
Mike, Coreen & Corey
Keswick Ridge, NB
------------------------------
Message: 9
Date: Sun, 8 Mar 2020 18:26:12 -0500
From: Jeff Blaine <KeepWalking188@ac0c.com>
To: topband@contesting.com
Subject: Re: Topband: Inverted L with elevated radials for topband
Message-ID: <7e155322-8efd-bf34-194c-e01b81d75bbd@ac0c.com>
Content-Type: text/plain; charset=utf-8; format=flowed
When it comes to elevated radials, the amount of guys who have strong
opinions on the subject are many - and unfortunately the amount of objective
data behind those strong opinions is generally not existent.?
On the other hand, the N6LF work is one of the few well documented objective
works available.
You won't go wrong drawing your radial design based on the N6LF graphs.?
As far as the performance and feedpoint question goes, build the best ground
you can and then cook up the match network based on the measured values.
73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com
On 3/5/20 5:43 PM, Grant Saviers wrote:
> comments in line
>
> On 3/5/2020 10:02, Gabriel - EA6VQ via Topband wrote:
>> I have some doubts about installing and inverted L with elevated
>> radials for 160m.? I have been searching in Google and find some
>> contradictory information, so I would appreciate very much if you can
>> help me with your own experience.
>>
> As noted by others, N6LF has a wealth of modeled and measured data on
> elevated radials.??? antennasbyn6lf.com
>
>>
>> The antenna would be supported by a 16 m (52.5 ft) high fiberglass
>> pole placed on top of a 3m (10 ft) high small tower with the
>> horizontal part of the L slopping down to a 5 m (16 ft) high mast
>> about 23 m (75 ft) away.? Two to four tuned elevated radials can be
>> placed, although they will have to be bent due to space restrictions.
>>
>>
> By "tuned" do you mean resonant 130ft +/-?? Again N6LF has data for 2
> to 16 elevated radials, and with more they can be shorter.
> Also see his paper in Antenna Compendium 8 re inductively loading for
> shorter radials.? I had only 2 75ft radials on a 52' mast.
>>
>> Now the doubts:
>>
>>
>> What impedance can I expect at the feed point with this configuration?
>>
> Having the radials as high as possible will minimize ground losses and
> decease Z.? With 2x at 10ft plan on 25 to 30 ohms.
>>
>> How to match it in order to feed it with a 50 ohm cable?? Some pages
>> say that no match is required, only a choke. Other pages say a
>> hairpin is necessary as the impedance can be too low. So other say
>> that a tuner at the base is required???? I am confused L
>>
>>
> SWR losses on 160 are so low that a 2:1 doesn't cost many db's. Too
> keep your amplifier happier I use a 50::25 ohm transmission line
> transformer.? make it or buy it.
>
> A good choke is a must.? Make the K9YC 4" #31 choke.
>
>>
>> What performance for DX can be achieved by this antenna?? Is it
>> really good or do you have some better suggestion for a really small
>> lot where no ground radials are possible?
>>
> You won't do better with anything else.? More radials will improve it
> slightly.
>>
>> Would it be worth to use a higher fiberglass pole, let's say 4 m (13
>> ft) higher, in order to lengthen the vertical section of the L? Would
>> the difference be noticeable?
>>
>>
> The taller the better but probably less than 1 db gain.
>
>>
>> Anyone has real experience setting up this antenna with elevated
>> radials?
>> Most information I can find on Internet is related to ground mounted
>> antennas.
>
> Read all of what Rudy N6LF says, and you will be an expert.
>
> Grant KZ1W
>
>
>>
>>
>> Thanks in advance!
>>
>>
>> 73. Gabriel - EA6VQ
>>
>>
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband
>> Reflector
>>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
------------------------------
Message: 10
Date: Sun, 8 Mar 2020 19:18:28 -0600
From: W0MU Mike Fatchett <w0mu@w0mu.com>
To: topband@contesting.com
Subject: Re: Topband: RBN and cluster spots
Message-ID: <d49eb9d6-91a0-a4b3-c5ce-4cad22f10c6e@w0mu.com>
Content-Type: text/plain; charset=utf-8; format=flowed
People can choose to turn on or off RBN spots and FT/x spots on CC clusters
like VE7CC.? My node W0MU-1 is connected to VE7CC and others and allows the
users to set spots how they like.? I also recommend CC USER VE7CC User
interface that easily allows you to set many many filters and you can
connect your contest software to CC User to take some of the strain of spots
off the logging software.
I have no clue why people would turn off RBN.? I wish we had one for SSB!
W0MU
On 3/8/2020 5:01 PM, Mike Smith VE9AA wrote:
> Steve,
>
>
>
> I wish I knew the answer to your question. When I go assisted in
> contests, (which is probably only 20-30% of the time)
>
> I connect to VE7CC which carries RBN spots. ( I prefer to tune for my
> DX, but that's another story)...I will go assisted if the sponsor does
> not differentiate between assisted and non-assisted..why would I want
> to tie 1-arm behind my back if there is no separate category?HI
>
>
>
> I don't know which clusters carry them in EU (or if EU's connect to
> VE7CC as
> well) but I *can* tell you that after only a couple CQ's in any big CW
> contest, I have the same hoard of EU big guns (mostly M/M's) call me,
> so that tells me it's (probably) an RBN spot.
>
>
>
> Then later, at other times things will be very dry for a long time and
> then I'll get a little mini "packet pileup" of normally weaker stns
> when apparently some kind soul has spotted me on a traditional
> Telnet/Packetcluster there in EU..often it's a flurry of mostly DL's,
> or mostly PA's, or mostly EA's (you get the idea)
>
>
>
> Because I normally run UNassisted, after every contest I'll do a
> search on dxscape or oh8x cluster to see who the kind souls were that
> spotted me and whether it coincided with the mini packet pileups and it
almost always is.
> Most times it's callsigns I don't readily recognize and they are not
> the big guns (who use the RBN_). I am always grateful we have both,
> but scratch my head why someone would only want 4cylinders naturally
> aspirated, when they can have 8 or 12 turbocharged!
>
>
>
> Seems sooooo easy to me. Connect to a cluster which carries RBN spots.
> Easy-Peasy.
>
>
>
> For reasons that I am not privy to, I still don't think many in EU do.
>
>
>
> Weird !
>
>
>
> Mike VE9AA..'course the RBN didn't help me at all this weekend on SSB, hi
!
>
>
>
> VE6WZ sez:
>
> ".It seems that quite a few ops out there either don't know about,
> have forgotten
>
> about, or somehow "don't believe" in the RBN network?? ."
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
------------------------------
Subject: Digest Footer
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
------------------------------
End of Topband Digest, Vol 207, Issue 10
****************************************
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|