John, was your power cord orange or yellow? Try black next time. 73
Ed K7UC
----- Original Message -----
From: "John Miller" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, February 28, 2011 7:00 PM
Subject: Re: RFI Saga continued
> My favorite recently was when I didn't realize my pet rabbit ate the power
> cord for the cable box in the living room. I found it alright. I had to
> tape
> that up, comcast will love to get that one back. It was more than I should
> have just taped but oh well. I got a nice jolt from that one.
> ----- Original Message -----
> From: "colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, February 28, 2011 8:13 PM
> Subject: Re: RFI Saga continued
>
>
>> and while I know we all learn, and are taught about treating electricity
>> with caution, and respect, and that how it takes x amount of tiny current
>> at
>> x amount of voltage to potentially stop the heart etc etc, you can still
>> grab onto an open 110/120VAC line and it'll only give you a bit of a
>> jolt...I've gotten that so many times I can't count from bad wall plugs
>> and
>> bad chord ends etc...try plugging the vehicle in at minus 25 when the
>> female
>> end of the extention chord has been lying in the snow and you have to get
>> rid of the snow plugging up the plug to insert the male part from the
>> vehicle...you get jolted a few times doing that let me tell you...though
>> after a few minutes, your fingers are numb enough from the cold that you
>> don't really feel it anyway hi hi.
>> at any rate, when your working on devices that have a step down
>> transformer
>> in them, best practice is to unplug, or turn the power off if you don't
>> need
>> the device to be operational while your working on it...however, if it is
>> unavoidable, like in this situation, there's not much harm in getting a
>> little buzz if you touch the wrong spot.
>> Also, if you unplug the thing and explore around inside before working on
>> it
>> while it's live, you can orient yourself to where the higher AC voltage
>> might be located. These days, most components have some sort of
>> insulation
>> around the high voltage contact points...such as at switches and where
>> the
>> AC connects to fuses and the main transformer.
>> Usually these things are designed with all the high voltage, as in
>> 120VAC,
>> connections set up on one side of the PCB...sometimes I just put
>> electrical
>> tape or duct tape over these connections if they are open so I don't
>> touch
>> them or short them or something like that.
>> It's easy to tell these connections because the wire is generally pretty
>> thick compared to other wiring in the device, and you can trace the wire
>> and
>> tape off solder points or whatever.
>> there is always a way, if there is the will.
>> I've been working on a solid state guitar amp lately. In order to
>> trouble
>> shoot the problem, it has to be turned on and operational in order for me
>> to
>> figure it out. I traced all the hot spots and covered them with
>> tape...and,
>> I know where the hot spots are located on the board so I stay away from
>> that
>> area as much as possible. I also taped the edges of the board and the
>> chassis edges so nothing will short to ground by accident while the board
>> is
>> floating around unanchored.
>> I did this of course after I shorted some hot point to the chassis, which
>> is
>> ground in this thing..and had a little flash and puff of
>> smoke...thankfully
>> nothing blew and all is well, other than the original issue.
>> So, respect power, and maintain considerate caution, but don't fear what
>> isn't there.
>> I mean, don't stick your tongue on a live 120Vac source or anything, but
>> getting a tingle in your fingers from accidentally touching it isn't
>> going
>> to hurt you or your equipment in any severe manner.
>> Allot of guys will use a rubber matt on the desk and floor while working
>> on
>> anything that is live...but again, not all that is necesary unless your
>> dealing with allot of humidity in the air or you have a real high ground
>> potential or high electrical resistance in your body.
>> everyone will react differently to electricity as well depending upon
>> their
>> biological make up.
>> 73
>> Colin, V A6BKX
>> ----- Original Message -----
>> From: "Butch Bussen" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Monday, February 28, 2011 5:03 PM
>> Subject: Re: RFI Saga continued
>>
>>
>>> You're making a mountain out of a mole hill. It won't bite you!!!
>>> Turning the switch on does nothing but connect the primary to a c. Just
>>> unplug and it will bleed off in half a minute or so. I've worked on
>>> them plugged in for years.
>>> 73
>>> Butch
>>> WA0VJR
>>>
>>> On Mon, 28 Feb 2011, tom behler wrote:
>>>
>>>> The other thing I was thinking of doing was unplugging the power
>>>> supply,
>>>> letting it set for a while, and then turning the switch on, in the
>>>> hopes
>>>> that this would help discharge the capacitors too.
>>>>
>>>> Any thoughts?
>>>>
>>>> 73 from Tom Behler: KB8TYJ
>>>>
>>>> ----- Original Message -----
>>>> From: "Butch Bussen" <[log in to unmask]>
>>>> To: <[log in to unmask]>
>>>> Sent: Monday, February 28, 2011 11:57 AM
>>>> Subject: Re: RFI Saga continued
>>>>
>>>>
>>>> The thing will discharge itself if you let it set a short while.
>>>> Second,
>>>> there is only 24 volts or so on a cap and I've worked on them hot and
>>>> as
>>>> long as you stay out of the primary 110 side, no worries. It won't zap
>>>> you.
>>>> 73
>>>> Butch
>>>> WA0VJR
>>>>
>>>>
>
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