[Elecraft] Issue 12 re Astron Power Supply

Tue Apr 17 01:22:24 EDT 2018

But I keep coming back to this: almost every device connected to the power supply has V- connected to ground internally. So if you have, say, a keyer and a transceiver running off the same supply, won’t some of the transceiver’s current flow through the V- line to the keyer, to the case of the keyer via the internal connection, to the station bonding, to the transceiver case and thence to the transceiver V- input?

In short, don’t the accessories fed from the same PS as the transceiver do exactly the same thing as the notorious black wire in the Astron?

Vic 4X6GP 

> On 16 Apr 2018, at 23:50, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> Joe is right and George is WRONG.  V- is NOT GROUND, it is the return for DC power.  Bonding V- to ground is a BAD idea -- that's why virtually all pro-grade power supplies are built either without the bond or so that the bond can easily be removed.
> 
> As to those who were confused by my advice -- I thought it was pretty plain.
> 
> Quite a few posts back, I posted a link to a detailed discussion of this on my website. I published this around 2010-12. I urge those who are confused to study it.
> 
> http://k9yc.com/PowerSupplyBondingAndAudioDistortion.pdf
> 
> My detailed advice on station grounding and bonding is the link below.  Much of it has been incorporated in Ward Silver's recent ARRL book on the topic, and is referenced in the book. You can buy the book from ARRL, while the pdf on my website is free. :)  Joe and Don are right on in their understanding of the NEC, the fundamentals of which I have been paid to teach to audio/video professionals in workshops at conventions.
> 
> http://k9yc.com/GroundingAndAudio.pdf
> 
> 73, Jim K9YC
> 
>> On 4/16/2018 7:06 AM, Joe Subich, W4TV wrote:
>> 
>> On 2018-04-16 9:28 AM, George Danner wrote:
>> > Re-Connect it!
>> 
>> DON'T CONNECT THAT WIRE BETWEEN V- AND CHASSIS CASE!
>> 
>> Unless you have a substantial *EXTERNAL GROUND CONNECTION*
>> between your station ground and the electrical system ground
>> rod, that connection between V- and chassis will bridge the
>> power system "safety" ground and the station grounding and
>> put your delicate and expensive equipment between two "grounds"
>> that can separate by many hundreds of volts in a lightning
>> event (or equipment failure).
>> 
>> > We even used ring grounds around studio & transmitter building with
>> > ground rods every 10' all cad-welded.
>> 
>> That is proper grounding and bonds all entry points together *OUTSIDE*
>> the building to prevent grounds from separating.  It creates a common
>> "island" for everything inside the building.  However, for the majority
>> of amateur stations which fail to properly bond the shields of all of
>> the coaxial cables entering the shack to the electrical system ground
>> *at the meter*, there is no "island" ... more like an isthmus across
>> the equipment.
>> 
>> 73,
>> 
>>    ... Joe, W4TV
>> 
>> 
>>> On 2018-04-16 9:28 AM, George Danner wrote:
>>> Re-Connect it!
>>> 
>>>> From a broadcaster (AM,FM & TV) was in South Florida (lightning capital of 
>>> North America).
>>> 
>>> The more massive the common (ground, bonding, whatever term you use) for the connection between equipment and the power company ground connection the better.
>>> We even used ring grounds around studio & transmitter building with ground rods every 10' all cad-welded. This is probably over kill for a ham station; but think as massive as you can.
>>> Towers at 500' or above had 2 ring grounds and lots of ground rods.
>>> 
>>> The common for equipment interconnection is for safety first and the reduction of voltage drops on the common lines that can transfer from one piece of equipment to another (us old timers use the term ground loop - not PC any more).
>>> 
>>> 73 George AI4VZ
>>> 
>>> -----Original Message----- From: Charlie T
>>> 
>>> "This greatly increases the chances for damages to station equipment and all other electronic equipment in the household in event of a lightning event."
>>> 
>>> What is, disconnecting the wire or leaving it in place?
>>> Your comment can be taken both ways.
>>> 
>>> 73, Charlie k3ICH
>>> 
>>> 
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft at mailman.qth.net
>>> 
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to lists at subich.com
>>> 
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to jim at audiosystemsgroup.com
>> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to k2vco.vic at gmail.com