I seem to remember this to be a touchy subject. Sorry to have fueled it in any
way. I have a great deal of respect for both Jim and Bob and to avoid the risk
of being alienated from this fellowship I will avoid further comment on the
subject....
Back to my Omni VI+ logic board repairs and such.
Cecil
K5DL
Sent from my iPad
On Sep 5, 2012, at 9:07 PM, "Wes Attaway \(N5WA\)" <wesattaway@bellsouth.net>
wrote:
> I respectively disagree that "all efforts for lightning protection must be
> outside the structure". It is clear that things need to be done both
> outside and inside.
>
> There are numerous ways that extensive damage can be done inside while
> nothing is damaged outside, and vice versa. You have to pay attention to
> the entire shebang or you are asking for trouble. Proper attention to
> inside grounding, and doing it correctly, is vitally important both for
> lightning protection and for human safety.
>
> I'll defer to Jim Brown for all the electrical code stuff.
>
>
> ----------------- Wes Attaway (N5WA) -------------------
> 1138 Waters Edge Circle, Shreveport, LA 71106
> 318-797-4972 (Office) - 318-393-3289 (Cell)
> Computer Consulting and Forensics
> -------------- EnCase Certified Examiner ---------------
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Robert
> Mcgraw
> Sent: Wednesday, September 05, 2012 8:52 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Station power supply??
>
> The discussion at length explaining lightning damage and the efforts that
> took place seem to indicate the lack of lightning protection outside of
> the building but stressed the efforts of providing extensive grounding
> inside the building for lightning protection. Clearly all efforts for
> lightning protection must be outside of the structure. Never provide a
> path or means that invites lightning into a building with the intent of
> running it to ground. All lightning protection efforts, arrestors, spark
> gaps, suppressors and grounding must be outside of the structure.
>
> The negative terminal of the power supply connected to chassis ground has
> nothing to do with it.
>
> 73
> Bob, K4TAX
>
>
>
>> I think it's important to differentiate between electrical safety
>> grounding and lightning protection grounding because I think that is some
>> of the confusion. The two are not the same and different techniques are
>> used in the application of both. The electrical safety grounding rules
>> are outlined in the NEC or NFPA...but a proper electrical safety
>> grounding system is a lousy lightning protection system in most all
>> cases. I noticed different grounding techniques mentioned in the recent
>> posts and they are a mixture of both. The station example with the
>> ground buss across the station console is most likely a lightning
>> protection application. The thing to keep in mind is to not compromise
>> electrical safety grounding in applying a lightning protection scheme.
>> Any lightning protection grounding system has to be bonded to the
>> electrical safety ground.
>>
>> Cecil
>> K5DL
>>
>> Sent from my iPad
>>
>> On Sep 5, 2012, at 7:26 PM, Jim Brown <k9yc@audiosystemsgroup.com> wrote:
>>
>>> On 9/5/2012 11:45 AM, Richards wrote:
>>>>
>>>>
>>>> Is this notion of bonding the V- to chassis in any way
>>>> related one could get shocked when touching the
>>>> chassis of an old Halicrafters tube sets?
>>>
>>> NO. But it IS caused when the GREEN WIRE is not properly bonded to the
>>> chassis, or when every chassis is not bonded to every other chassis and
>>> to ground. That GREEN WIRE IS GROUND, coming all the way from the
>>> breaker panel that feeds it. It's not a great RF ground, but it's a
>>> great SAFETY ground, and it is required by LAW in virtually every
>>> developed country. .
>>>
>>>>
>>>>
>>>> Observation:
>>>>
>>>> [I am still taking Electronics 101. But I remember the
>>>> time I got stung touching a hot chassis.}
>>>>
>>>> I would have thought a serious concept like grounding stuff would be
>>>> so important, it would be codified in a consistent set of rules even
>>>> rookie operators could apply and follow.
>>>
>>> It is, that "codification is the National Electric Code (NEC), and
>>> there is excellent material on this in recent editions of the ARRL
>>> Handbook.
>>>
>>>> Also, I would have thought the product manufacturers would be on one
>>>> track, with consistent instructions and consistency in the gear.
>>>
>>> The Astrons are DESIGNED correctly, but the PAINT is a manufacturing
>>> defect.
>>>
>>>>
>>>> But... NOOooo... that would be too easy! Consider, f'rinstance,
>>>> this topic of grounding power supply chassis. Nearly every rig needs
>>>> a power supply. Nearly every instruction manual says to ground each
>>>> chassis to the other ones, and to a stick in the mud. Even TenTec says
>>>> to do that in my transceiver user manual.
>>>>
>>>> OK... but then there is no ground lug on my TT 963 power supply. There
>>>> is no ground lug on 2 of my Astron power supplies.
>>>
>>> Well, there is, it's called the GREEN WIRE.
>>>
>>>> There is no ground lug on my TT receiver, and similarly no ground lug
>>>> on most of of my station accessories. And yet they all have AC or DC
>>>> power.
>>>
>>> That's unusual. Most ham rigs I've seen have a ground lug.
>>>
>>>> Some guys say to wire the green wire to the chassis (which I somehow
>>>> get) but then other guys debate wiring the negative to chassis (which
>>>> I don't get, because I remember the sting of my old radio years ago).
>>>> Some advocate adding a ground lug to the power supply chassis - but
>>>> the manufacturer did not.
>>>>
>>>> And then TenTec service told me not to ground ANY of it unless I have
>>>> a specific problem to solve, which just a little contradicts what it
>>>> says in the instruction manual. Some guys have grounding bars across
>>>> the back of their desks. Others don't have anything. One would have
>>>> thought, if all these things are supposed to work together, there
>>>> would be a common way of doing it.
>>>
>>> That's why it's important to develop an effective BS filter. One of
>>> the best BS filters is EDUCATION. You're an attorney, as I recall, so
>>> I'll bet you've got a pretty good BS filter in that field, and to some
>>> extent with respect human nature and reading people. But until you
>>> develop your technical BS filter (see education, above) you're always
>>> going to be wondering who to believe.
>>>
>>>> Heck, now you guys say even Astron is inconsistent over time - and on
>>>> the same model supply, too. And now we are all wrangling over
>>>> different rules and approaches to it.
>>>
>>> The only RULES here are that, BY LAW, EVERY exposed chassis MUST be
>>> bonded to ground, if it's connected to the power line, it MUST be
>>> bonded to the Green Wire, and ALL grounds MUST BE bonded together. And
>>> for good RF performance, and to minimize hum and buzz, those bonds
>>> should be short fat copper.
>>>
>>> FWIW, I've written extensively about all of this stuff in tutorials
>>> that are on my website. All you have to do is study them.
>>>
>>> 73, Jim K9YC
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
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