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Mac Grounding

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David Guernsey

Mac Grounding

I have a Mac Mini sitting right next to my K3/10 on my desk and have had no
problems. The radio is grounded of course, but the computer is not.

73s de Dave KJ6CBS
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Wolf E. Rose

Re: Mac Grounding

same with me, except it's a K3/100 on HF and K3/10 on UHF (through
transverter TR432H). Running 750W on HF (sometimes) and up to 700W on
UHF (during contests) there are absolutely no problems. Rigs are
connected via an Edgeport USB - 4Serial-converter and audio in/out
phono lines.

73 Wolf DK1IP

> I have a Mac Mini sitting right next to my K3/10 on my desk and have
> had no
> problems. The radio is grounded of course, but the computer is not.
>
>
> 73s de Dave KJ6CBS
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Jim Brown-10

Re: Mac Grounding

In reply to this post by David Guernsey

On 4/10/2011 2:29 PM, David Guernsey wrote:
> The radio is grounded of course, but the computer is not.

EVERY piece of equipment in a ham shack should its chassis bonded to
every other chassis in the shack, and to your earth ground system. This
includes the computer. Doing so will minimize problems with hum, buzz,
and RFI. It also tends to minimize lightning damage.

A tutorial on this is part of http://audiosystemsgroup.com/RFI-Ham.pdf
and in

http://audiosystemsgroup.com/HamInterfacing.pdf

73, Jim Brown K9YC
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Phil Hystad-3

Re: Mac Grounding

Follow up on some of this discussion...

Any wiring made to an Apple computer that is not supported via
standard cabling (e.g. USB, Firewire, etc., video, etc.) is not
authorized and may violate the warranty. This is essentially what
it says in my iMac 24 user guide. I did not quote it exactly since
it is about 3 paragraphs long with really tiny print.

As far as I know, I do not have an RFI problem in my shack and
I am certainly not going to ground my computer (other then the
grounding plug for the 120 volt AC connection) nor will I put
a ground strap wire on my laptop. I mean, does anyone really
do that?

But, like I said, I do not have any hum, buzz, or RFI that I
know of and if I don't know of it it certainly does not bother me.

peh

On Apr 11, 2011, at 8:58 AM, Jim Brown wrote:

> On 4/10/2011 2:29 PM, David Guernsey wrote:
>> The radio is grounded of course, but the computer is not.
>
> EVERY piece of equipment in a ham shack should its chassis bonded to
> every other chassis in the shack, and to your earth ground system. This
> includes the computer. Doing so will minimize problems with hum, buzz,
> and RFI. It also tends to minimize lightning damage.
>
> A tutorial on this is part of http://audiosystemsgroup.com/RFI-Ham.pdf
> and in
>
> http://audiosystemsgroup.com/HamInterfacing.pdf
>
> 73, Jim Brown K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
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Rick Prather-2

Re: Mac Grounding

Yes, I do. I have a ground strap running from my iMac to the radio and can tell the difference when using sound card modes.

Just for fun you might take a Volt meter on low scale and check from the iMac chassis to the radio chassis. You may be surprised at how much potential difference there is. Especially if they aren't both plugged in to the same house circuit (and even if they are)

Rick
K6LE

On 4/11/2011, at 4:39 , Phil Hystad wrote:

I mean, does anyone really
> do that?
>
> But, like I said, I do not have any hum, buzz, or RFI that I
> know of and if I don't know of it it certainly does not bother me.
>
> peh
>

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Raymond Sills

Re: Mac Grounding

Hi Rick:

Where to you connect that ground strap? My iMac (17" Intel) is
totally encased in plastic!

73 de Ray
K2ULR

On Apr 11, 2011, at 8:46 PM, Rick Prather wrote:

> Yes, I do. I have a ground strap running from my iMac to the
> radio and can tell the difference when using sound card modes.
>
> Just for fun you might take a Volt meter on low scale and check
> from the iMac chassis to the radio chassis. You may be surprised
> at how much potential difference there is. Especially if they
> aren't both plugged in to the same house circuit (and even if they
> are)
>
> Rick
> K6LE

Joe Subich, W4TV-4

Re: Mac Grounding

In reply to this post by Phil Hystad-3

If you don't bond the computer chassis to the radio system
ground you stand a very good chance of blowing the USB
ports or your USB to serial interface in the event of a
nearby lightning strike.

Most amateur installations fail to properly bond the tower,
"ground stake" where the antenna feedlines and control lines
enter the shack and the power (utility) service entrance
grounds together. Since the service entrance ground is
the power system "safety ground" any difference in the
ground potential between the RF system (antenna/tower) and
the safety (utility) ground will appear directly across the
USB devices. Since the difference in potential can be many
hundred volts and the USB port/devices are 5V DC devices,
can see how quickly the devices can be damaged when one of
the "grounds" reverse biases the diodes in the devices <G>!

If you *don't* bond the computer chassis to the RF system
ground, disconnect *ALL* connections between the computer
and radio when you are not using them.

73,

... Joe, W4TV

On 4/11/2011 7:39 PM, Phil Hystad wrote:

> Follow up on some of this discussion...
>
> Any wiring made to an Apple computer that is not supported via
> standard cabling (e.g. USB, Firewire, etc., video, etc.) is not
> authorized and may violate the warranty. This is essentially what
> it says in my iMac 24 user guide. I did not quote it exactly since
> it is about 3 paragraphs long with really tiny print.
>
> As far as I know, I do not have an RFI problem in my shack and
> I am certainly not going to ground my computer (other then the
> grounding plug for the 120 volt AC connection) nor will I put
> a ground strap wire on my laptop. I mean, does anyone really
> do that?
>
> But, like I said, I do not have any hum, buzz, or RFI that I
> know of and if I don't know of it it certainly does not bother me.
>
> peh
>
>
> On Apr 11, 2011, at 8:58 AM, Jim Brown wrote:
>
>> On 4/10/2011 2:29 PM, David Guernsey wrote:
>>> The radio is grounded of course, but the computer is not.
>>
>> EVERY piece of equipment in a ham shack should its chassis bonded to
>> every other chassis in the shack, and to your earth ground system. This
>> includes the computer. Doing so will minimize problems with hum, buzz,
>> and RFI. It also tends to minimize lightning damage.
>>
>> A tutorial on this is part of http://audiosystemsgroup.com/RFI-Ham.pdf
>> and in
>>
>> http://audiosystemsgroup.com/HamInterfacing.pdf
>>
>> 73, Jim Brown K9YC
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Phil Hystad-3

Re: Mac Grounding

In reply to this post by Rick Prather-2

Rick,

Since I don't make use of a sound card interface, I don't see the problem you mention. I do digital from time to time but use Signalink USB and have never noticed a problem.

I just measured the voltage and it is essentially zero between my iMac and my K3 grounds (using a Fluke 189 DVM). My iMac is plugged into my UPS but the UPS is plugged into the same power circuit as the Astron power supply that drives the K3. I also put both plugs of my Fluke meter on my ground strap to see if it had the same noise level (millivolt readings) as between the K3 and the iMac and it is indeed about the same. I am not sure though if the aluminum parts of my iMac are the true ground of the computer itself, that could very well be different. Only the newer iMacs have the aluminum (I think it is aluminum) frame, my older iMac had plastic all over the thing -- no metal that I could tell.

peh

On Apr 11, 2011, at 5:46 PM, Rick Prather wrote:

> Yes, I do. I have a ground strap running from my iMac to the radio and can tell the difference when using sound card modes.
>
> Just for fun you might take a Volt meter on low scale and check from the iMac chassis to the radio chassis. You may be surprised at how much potential difference there is. Especially if they aren't both plugged in to the same house circuit (and even if they are)
>
> Rick
> K6LE
>
> On 4/11/2011, at 4:39 , Phil Hystad wrote:
>
>
> I mean, does anyone really
>> do that?
>>
>> But, like I said, I do not have any hum, buzz, or RFI that I
>> know of and if I don't know of it it certainly does not bother me.
>>
>> peh
>>
>

Bob K6UJ

Re: Mac Grounding

In reply to this post by Jim Brown-10

How do I ground my MacBook Pro laptop ?

Bob
K6UJ

On Apr 11, 2011, at 8:58 AM, Jim Brown wrote:

Rick Prather-2

Re: Mac Grounding

In reply to this post by Raymond Sills

I have the aluminum 24" and I use a screw clamp on the aluminum leg on the back.

Definitely eliminated the potential difference I used to see from the Mac to the radio.

As much as I love Mac's there is nothing inherently magic about them that disallows the need for proper grounding.

Also, running a ground strap is not in any way going to alter the warranty.

In Phil's case, even using the SignalLink (for whatever reason) does not preclude the possibility of needing the units bonded together.

I wondered how long it would take K9YC to weigh in on this and I'm sure he can do a much better job of explaining the requirement. Taking a look at his tutorial is an excellent idea.

Rick
K6LE

On 4/11/2011, at 5:53 , Ray Sills wrote:

> Hi Rick:
>
> Where to you connect that ground strap? My iMac (17" Intel) is
> totally encased in plastic!
>
> 73 de Ray
> K2ULR
>

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Bob K6UJ

Re: Mac Grounding

I have two Mac laptop computers in the shack. An aluminum encased MacBook Pro and a plastic cased MacBook.
Is their a way to ground these without drilling/clamping etc ? I understand the need but I'm not very excited
about modifying my Macs to provide grounding.

Bob
K6UJ

On Apr 11, 2011, at 6:37 PM, Rick Prather wrote:

> I have the aluminum 24" and I use a screw clamp on the aluminum leg on the back.
>
> Definitely eliminated the potential difference I used to see from the Mac to the radio.
>
> As much as I love Mac's there is nothing inherently magic about them that disallows the need for proper grounding.
>
> Also, running a ground strap is not in any way going to alter the warranty.
>
> In Phil's case, even using the SignalLink (for whatever reason) does not preclude the possibility of needing the units bonded together.
>
> I wondered how long it would take K9YC to weigh in on this and I'm sure he can do a much better job of explaining the requirement. Taking a look at his tutorial is an excellent idea.
>
> Rick
> K6LE
>
> On 4/11/2011, at 5:53 , Ray Sills wrote:
>
>> Hi Rick:
>>
>> Where to you connect that ground strap? My iMac (17" Intel) is
>> totally encased in plastic!
>>
>> 73 de Ray
>> K2ULR
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Phil Hystad-3

Re: Mac Grounding

I understand the technical reasons that people suggest for grounding but I do not see the need. I have no problems. If there are problems, they are invisible to me. By the way, my Signalink is connected to my Mac only when I am using it. The reason is that I usually use the Signalink from my laptop and not my iMac and most of the time I am not using the Signalink. I think I last did PSK31 about two weeks ago and that was the first time in several months.

At least 90 percent of all my contacts are CW. I never use a computer in tandem with my radio work. I think that is a real hassle and it does not interest me. I do enter log information in my own home grown logging application but I do not interface the computers to the radio. The only reason I do that is when I need to do a K3 or P3 firmware upgrade and when I do PSK31 (both of these are relatively rare events).

By the way, I do love ham radio but I am in front of my laptop (usually sitting on the couch here in my room) more then I am in front of my radios. Thus, my computers are situated for all my programming activities, not for radio work.

phil

On Apr 11, 2011, at 6:45 PM, Robert Harmon wrote:

> I have two Mac laptop computers in the shack. An aluminum encased MacBook Pro and a plastic cased MacBook.
> Is their a way to ground these without drilling/clamping etc ? I understand the need but I'm not very excited
> about modifying my Macs to provide grounding.
>
> Bob
> K6UJ
>
>
>
>
> On Apr 11, 2011, at 6:37 PM, Rick Prather wrote:
>
>> I have the aluminum 24" and I use a screw clamp on the aluminum leg on the back.
>>
>> Definitely eliminated the potential difference I used to see from the Mac to the radio.
>>
>> As much as I love Mac's there is nothing inherently magic about them that disallows the need for proper grounding.
>>
>> Also, running a ground strap is not in any way going to alter the warranty.
>>
>> In Phil's case, even using the SignalLink (for whatever reason) does not preclude the possibility of needing the units bonded together.
>>
>> I wondered how long it would take K9YC to weigh in on this and I'm sure he can do a much better job of explaining the requirement. Taking a look at his tutorial is an excellent idea.
>>
>> Rick
>> K6LE
>>
>> On 4/11/2011, at 5:53 , Ray Sills wrote:
>>
>>> Hi Rick:
>>>
>>> Where to you connect that ground strap? My iMac (17" Intel) is
>>> totally encased in plastic!
>>>
>>> 73 de Ray
>>> K2ULR
>>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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Don Wilhelm-4

Re: Mac Grounding

Phil,

May I suggest that your operating situation is not the norm. There are
those using Macs who do need to know how to bond the computer ground
into their station ground system. Please do not discourage them just
because your operation does not need it.

Even in your case, if a surge event does occur, there can be a personnel
danger if one part of your body is in contact with the computer, while
another part is in contact with a properly grounded piece of radio
equipment. It is more than just a noise creating situation, it is a
matter of your safety while in the radio shack.

Having two pieces of equipment at different chassis potentials is not a
good thing. The differential may be small and tolerable under normal
conditions, but in the case of a surge event, that difference can be
huge, and even life threatening. While Jim Brown's documents
concentrate on noise created by small differences in ground potential,
there is another side of the story, and that is one of safety - not
under normal conditions, but during a surge event.

73,
Don W3FPR

On 4/11/2011 10:11 PM, Phil Hystad wrote:

> I understand the technical reasons that people suggest for grounding but I do not see the need. I have no problems. If there are problems, they are invisible to me. By the way, my Signalink is connected to my Mac only when I am using it. The reason is that I usually use the Signalink from my laptop and not my iMac and most of the time I am not using the Signalink. I think I last did PSK31 about two weeks ago and that was the first time in several months.
>
> At least 90 percent of all my contacts are CW. I never use a computer in tandem with my radio work. I think that is a real hassle and it does not interest me. I do enter log information in my own home grown logging application but I do not interface the computers to the radio. The only reason I do that is when I need to do a K3 or P3 firmware upgrade and when I do PSK31 (both of these are relatively rare events).
>
> By the way, I do love ham radio but I am in front of my laptop (usually sitting on the couch here in my room) more then I am in front of my radios. Thus, my computers are situated for all my programming activities, not for radio work.
>
> phil
>
>
> On Apr 11, 2011, at 6:45 PM, Robert Harmon wrote:
>
>> I have two Mac laptop computers in the shack. An aluminum encased MacBook Pro and a plastic cased MacBook.
>> Is their a way to ground these without drilling/clamping etc ? I understand the need but I'm not very excited
>> about modifying my Macs to provide grounding.
>>
>> Bob
>> K6UJ
>>
>>
>>
>>
>> On Apr 11, 2011, at 6:37 PM, Rick Prather wrote:
>>
>>> I have the aluminum 24" and I use a screw clamp on the aluminum leg on the back.
>>>
>>> Definitely eliminated the potential difference I used to see from the Mac to the radio.
>>>
>>> As much as I love Mac's there is nothing inherently magic about them that disallows the need for proper grounding.
>>>
>>> Also, running a ground strap is not in any way going to alter the warranty.
>>>
>>> In Phil's case, even using the SignalLink (for whatever reason) does not preclude the possibility of needing the units bonded together.
>>>
>>> I wondered how long it would take K9YC to weigh in on this and I'm sure he can do a much better job of explaining the requirement. Taking a look at his tutorial is an excellent idea.
>>>
>>> Rick
>>> K6LE
>>>
>>> On 4/11/2011, at 5:53 , Ray Sills wrote:
>>>
>>>> Hi Rick:
>>>>
>>>> Where to you connect that ground strap? My iMac (17" Intel) is
>>>> totally encased in plastic!
>>>>
>>>> 73 de Ray
>>>> K2ULR
>>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

K2QI

Re: Mac Grounding

Forgive me if I misunderstood Don's response, but normally a computer regardless of make or model is grounded via the power supply negating any need for additional measures.

The above statement is only applicable if the home ground has been properly facilitated. Of course, all bets are off if this is not the case.

Apart from that, OS or computer make if grounded correctly should not pose any threat in a station should the shack's earth ground fail.

Please correct me if I'm wrong, but what Phil has described has been the norm at 4U1UN for many years without fail; not by choice but due to wiring restrictions and location the club has endured for many years.

73,
James K2QI
Sent via BlackBerry from T-Mobile

-----Original Message-----
From: Don Wilhelm <[hidden email]>
Sender: [hidden email]
Date: Mon, 11 Apr 2011 22:27:12
To: Phil Hystad<[hidden email]>
Reply-To: [hidden email]
Cc: Rick Prather<[hidden email]>; elecraft<[hidden email]>
Subject: Re: [Elecraft] Mac Grounding

Phil,

May I suggest that your operating situation is not the norm. There are
those using Macs who do need to know how to bond the computer ground
into their station ground system. Please do not discourage them just
because your operation does not need it.

Even in your case, if a surge event does occur, there can be a personnel
danger if one part of your body is in contact with the computer, while
another part is in contact with a properly grounded piece of radio
equipment. It is more than just a noise creating situation, it is a
matter of your safety while in the radio shack.

Having two pieces of equipment at different chassis potentials is not a
good thing. The differential may be small and tolerable under normal
conditions, but in the case of a surge event, that difference can be
huge, and even life threatening. While Jim Brown's documents
concentrate on noise created by small differences in ground potential,
there is another side of the story, and that is one of safety - not
under normal conditions, but during a surge event.

73,
Don W3FPR

On 4/11/2011 10:11 PM, Phil Hystad wrote:

______________________________________________________________
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______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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--... ...-- -.. . .--- .- -- . ...

Don Wilhelm-4

Re: Mac Grounding

James,

Yes, the ground through the AC line cord is "possibly" OK, but may or
may not ground a laptop to the AC mains ground - it all depends on the
design of the computer and its power supply. It also depends on having
the computer plugged into the same receptacle that the rest of the ham
station equipment is using, and that any ham station ground rods are
bonded back to the electrical utility ground system. That is not the
situation for many ham stations, particularly the part about bonding the
station ground rods to the Utility entrance ground.

There are just too many "ifs" to say for certain whether a problem can
exist or not. The claims of one Mac user do not mitigate the fact that
there is a potential hazard just waiting to do its dirty work. Keep
yourself safe.

An entirely plastic computer may not pose a hazard, much as double
insulated power tools protect the user without need for a ground, but
there are just too many variables here - some talk of Macs with plastic
cases, and others talk of Macs with exposed aluminum parts. Some may be
OK, but others may not - it all depends... As I indicated, err on the
side of caution and keep yourself safe. We do not need any silent keys
added because of situations like this.

73,
Don W3FPR

On 4/11/2011 10:40 PM, [hidden email] wrote:

> Forgive me if I misunderstood Don's response, but normally a computer regardless of make or model is grounded via the power supply negating any need for additional measures.
>
> The above statement is only applicable if the home ground has been properly facilitated. Of course, all bets are off if this is not the case.
>
> Apart from that, OS or computer make if grounded correctly should not pose any threat in a station should the shack's earth ground fail.
>
> Please correct me if I'm wrong, but what Phil has described has been the norm at 4U1UN for many years without fail; not by choice but due to wiring restrictions and location the club has endured for many years.
>
> 73,
> James K2QI
> Sent via BlackBerry from T-Mobile
>
> -----Original Message-----
> From: Don Wilhelm<[hidden email]>
> Sender: [hidden email]
> Date: Mon, 11 Apr 2011 22:27:12
> To: Phil Hystad<[hidden email]>
> Reply-To: [hidden email]
> Cc: Rick Prather<[hidden email]>; elecraft<[hidden email]>
> Subject: Re: [Elecraft] Mac Grounding
>
> Phil,
>
> May I suggest that your operating situation is not the norm. There are
> those using Macs who do need to know how to bond the computer ground
> into their station ground system. Please do not discourage them just
> because your operation does not need it.
>
> Even in your case, if a surge event does occur, there can be a personnel
> danger if one part of your body is in contact with the computer, while
> another part is in contact with a properly grounded piece of radio
> equipment. It is more than just a noise creating situation, it is a
> matter of your safety while in the radio shack.
>
> Having two pieces of equipment at different chassis potentials is not a
> good thing. The differential may be small and tolerable under normal
> conditions, but in the case of a surge event, that difference can be
> huge, and even life threatening. While Jim Brown's documents
> concentrate on noise created by small differences in ground potential,
> there is another side of the story, and that is one of safety - not
> under normal conditions, but during a surge event.
>
> 73,
> Don W3FPR
>
>
>
> On 4/11/2011 10:11 PM, Phil Hystad wrote:
>> I understand the technical reasons that people suggest for grounding but I do not see the need. I have no problems. If there are problems, they are invisible to me. By the way, my Signalink is connected to my Mac only when I am using it. The reason is that I usually use the Signalink from my laptop and not my iMac and most of the time I am not using the Signalink. I think I last did PSK31 about two weeks ago and that was the first time in several months.
>>
>> At least 90 percent of all my contacts are CW. I never use a computer in tandem with my radio work. I think that is a real hassle and it does not interest me. I do enter log information in my own home grown logging application but I do not interface the computers to the radio. The only reason I do that is when I need to do a K3 or P3 firmware upgrade and when I do PSK31 (both of these are relatively rare events).
>>
>> By the way, I do love ham radio but I am in front of my laptop (usually sitting on the couch here in my room) more then I am in front of my radios. Thus, my computers are situated for all my programming activities, not for radio work.
>>
>> phil
>>
>>
>> On Apr 11, 2011, at 6:45 PM, Robert Harmon wrote:
>>
>>> I have two Mac laptop computers in the shack. An aluminum encased MacBook Pro and a plastic cased MacBook.
>>> Is their a way to ground these without drilling/clamping etc ? I understand the need but I'm not very excited
>>> about modifying my Macs to provide grounding.
>>>
>>> Bob
>>> K6UJ
>>>
>>>
>>>
>>>
>>> On Apr 11, 2011, at 6:37 PM, Rick Prather wrote:
>>>
>>>> I have the aluminum 24" and I use a screw clamp on the aluminum leg on the back.
>>>>
>>>> Definitely eliminated the potential difference I used to see from the Mac to the radio.
>>>>
>>>> As much as I love Mac's there is nothing inherently magic about them that disallows the need for proper grounding.
>>>>
>>>> Also, running a ground strap is not in any way going to alter the warranty.
>>>>
>>>> In Phil's case, even using the SignalLink (for whatever reason) does not preclude the possibility of needing the units bonded together.
>>>>
>>>> I wondered how long it would take K9YC to weigh in on this and I'm sure he can do a much better job of explaining the requirement. Taking a look at his tutorial is an excellent idea.
>>>>
>>>> Rick
>>>> K6LE
>>>>
>>>> On 4/11/2011, at 5:53 , Ray Sills wrote:
>>>>
>>>>> Hi Rick:
>>>>>
>>>>> Where to you connect that ground strap? My iMac (17" Intel) is
>>>>> totally encased in plastic!
>>>>>
>>>>> 73 de Ray
>>>>> K2ULR
>>>>>
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K2QI

Re: Mac Grounding

Hi Don,

Thank you for replying directly to my post. I have no doubt that the precautions you've mentioned aren't without merit.

All I was trying to convey was that there is good chance the OPs Macintosh is well grounded as are most commercially assembled computers.

I can recall several occasions when I was "bitten" in the shack by poorly grounded gear, including at our UN station, but none have actually involved the computers. Fortunately, most cases required simply preventing RF energy from traveling back to the shack via the coax shield. Others were more complex and needed proper bonding to earth ground via copper plumbing. In all instances however, no issues involved the CPU units themselves.

You are correct though that safety is paramount, and if one finds that any piece in their shack is poorly grounded, common sense would compel them to rectify the situation post-haste.

73,
James K2QI
Sent via BlackBerry from T-Mobile

-----Original Message-----
From: Don Wilhelm <[hidden email]>
Date: Mon, 11 Apr 2011 23:40:12
To: <[hidden email]>
Reply-To: [hidden email]
Cc: Phil Hystad<[hidden email]>; Rick Prather<[hidden email]>; Elecraft Reflector<[hidden email]>
Subject: Re: [Elecraft] Mac Grounding

James,

Yes, the ground through the AC line cord is "possibly" OK, but may or
may not ground a laptop to the AC mains ground - it all depends on the
design of the computer and its power supply. It also depends on having
the computer plugged into the same receptacle that the rest of the ham
station equipment is using, and that any ham station ground rods are
bonded back to the electrical utility ground system. That is not the
situation for many ham stations, particularly the part about bonding the
station ground rods to the Utility entrance ground.

There are just too many "ifs" to say for certain whether a problem can
exist or not. The claims of one Mac user do not mitigate the fact that
there is a potential hazard just waiting to do its dirty work. Keep
yourself safe.

An entirely plastic computer may not pose a hazard, much as double
insulated power tools protect the user without need for a ground, but
there are just too many variables here - some talk of Macs with plastic
cases, and others talk of Macs with exposed aluminum parts. Some may be
OK, but others may not - it all depends... As I indicated, err on the
side of caution and keep yourself safe. We do not need any silent keys
added because of situations like this.

73,
Don W3FPR

On 4/11/2011 10:40 PM, [hidden email] wrote:

--... ...-- -.. . .--- .- -- . ...

Jim Brown-10

Re: Mac Grounding

In reply to this post by Bob K6UJ

On 4/11/2011 6:31 PM, Robert Harmon wrote:
> How do I ground my MacBook Pro laptop ?

Study the links I posted.

73, Jim K9YC
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Byron Servies

Re: Mac Grounding

In reply to this post by Phil Hystad-3

Hi Phil,

I think what people are trying to point out is that the instant the
need becomes visible, it will be too late. May that time never come,
and good luck!

On Mon, Apr 11, 2011 at 7:11 PM, Phil Hystad <[hidden email]> wrote:
> I understand the technical reasons that people suggest for grounding but I do not see the need.
> I have no problems.

--
73, Byron N6NUL
----
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Edward R Cole

Mac Grounding

In reply to this post by David Guernsey

None of my computer chassis are grounded directly to my radio
grounds. I made it especially that way to avoid audio ground
loops. All the computers are normal appliances with UL rated
connections to AC mains which are required by code to have a safety
ground tied to the main service entrance. You do not see the
millions of computer users worrying about having extra grounding on
the computers.

IF your home has improper AC wiring then FIX that. There is no need
for extra grounding if your home is properly wired. Lightning is
something that no amount of grounding will prevent. This has also
been thoroughly discussed for those that want to know how to protect
equipment from lightning.

More important is that the radio equipment have better grounding for
RF as well as safety. I do that thru a #8 awg wire to an outside
ground rod. Beyond saying that, the topic of grounding in the ham
shack has been thoroughly discussed on this reflector (and should not
need further discussion).

That's my two cents on this topic and all you will hear from me on it.

73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-1.4kw, 432-100w, 1296-testing*, 3400-winter?
DUBUS Magazine USA Rep [hidden email]
======================================
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Buck - k4ia

Re: Mac Grounding

I found it necessary to ground my computer chassis to prevent the
incursion of RFI. I scraped off some paint on the rear and bolted a
ground strap from there to my star point ground system for the shack.
It was not an issue of safety ground but of RF being induced into the
computer from the nearby antennas. My RFI manifested itself as
distortion when using the soundcard as a DVR for contests. The
recording sounded fine but what went out over the air was distorted.

I also had to perform the pin1 mods to my early serial number K3.
Anyone having RFI issues should investigate these mods. Info is
available on the Elecraft website under Alerts, Enhancements and
Application Notes. There are two mods - one to the microphone jack and
one to the real panel.

After doing the above, I have had no more problems with RFI.

Buck
k4ia

On 4/12/2011 2:07 PM, Edward R. Cole wrote:

> None of my computer chassis are grounded directly to my radio
> grounds. I made it especially that way to avoid audio ground
> loops. All the computers are normal appliances with UL rated
> connections to AC mains which are required by code to have a safety
> ground tied to the main service entrance. You do not see the
> millions of computer users worrying about having extra grounding on
> the computers.
>
> IF your home has improper AC wiring then FIX that. There is no need
> for extra grounding if your home is properly wired. Lightning is
> something that no amount of grounding will prevent. This has also
> been thoroughly discussed for those that want to know how to protect
> equipment from lightning.
>
> More important is that the radio equipment have better grounding for
> RF as well as safety. I do that thru a #8 awg wire to an outside
> ground rod. Beyond saying that, the topic of grounding in the ham
> shack has been thoroughly discussed on this reflector (and should not
> need further discussion).
>
> That's my two cents on this topic and all you will hear from me on it.
>
>
> 73, Ed - KL7UW, WD2XSH/45
> ======================================
> BP40IQ 500 KHz - 10-GHz www.kl7uw.com
> EME: 144-1.4kw, 432-100w, 1296-testing*, 3400-winter?
> DUBUS Magazine USA Rep [hidden email]
> ======================================
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

123