On 3/6/2012 8:35 AM, TexasRF@aol.com wrote:
> Hi All, if the phone/camera has issues with rf you have to wonder about
> long term effects on the operator. One would think that brain tissue is less
> robust than a cell phone.
>
> Scary stuff!
Not really. That's not even an apples to oranges comparison. It
takes a pretty intense RF field to affect body tissue and it varies
with frequency. Your 2-meter HT probably exposes you to a 1000 times of
more exposure than the amp. Probably a lot more as the antenna is right
next to your skull. Add to that 2-meters has far more effect on tissue
than HF.
You can get within a few feet of the end of your 75 meter dipole being
fed 1.5 KW without exceeding the exposure limits.. You must be much
farther on 2-meters
However were my amp that leaky I'd borrow a calibrated field strength
meter and test the level of RF to which you are being exposed.
The following is not a recommendation:
I've worked on amps with the covers off (Yes I know what "they" say
about never working on one live with the covers off.) Having worked on
several hundred KW with the doors open its never bothered me. You
remove all metal before doing such things. No neck chains when leaning
over your pet project either<:-))
73
Roger (K8RI)
>
> 73,
> Gerald K5GW
>
>
>
>
> In a message dated 3/6/2012 7:29:36 A.M. Central Standard Time,
> lists@w1nr.net writes:
>
> I just took some photos of my rather poorly shielded 4-1000 amplifier
> running key down carrier on 20M with my Nikon D90 and did not notice any
> issues at all. Neither have I seen issues with my Android smart phone in
> the shack at any time during a contest weekend.
>
> Mike, W1NR
>
>
> On 03/05/2012 10:08 PM, Charles Harpole wrote:
>> High RF fields ... like being in a shack with two KWs running, puts
> lines in the video of a SONY PD -100 model camera. Tested.
>> Charles Harpole
>> k4vud@hotmail.com
>> > Date: Mon, 5 Mar 2012 15:43:06 -0500
>>> From: k8ri@rogerhalstead.com
>>> To: amps@contesting.com
>>> Subject: Re: [Amps] Cell phones, digital cameras and RF
>>>
>>> On 3/5/2012 12:40 PM, Fuqua, Bill L wrote:
>>>> How many times have you taken a picture of an amplifier tube
> glowing very red with the cover removed and with a cell phone or digital
> camera?
>>>> I have done it a number of times and yet the relatively intense RF
> electric fields seem to have no effect. I have taken photos of my 4-1000A amp
> with
>>>> bright red plate and probably 6 or 7kV p-p rf only a foot away or so.
>>>> They must be very well shielded!
>>> They are poorly shielded, but their operating frequencies and physical
>>> construction makes them pretty much immune to HF.
>>> I've never used the camera in the cell phone because no matter how many
>>> pixels they brag about they are limited by the laws of physics and that
>>> tiny lens.
>>> Even the digital SLRs are limited by the lens but with those you can get
>>> the equivalent of a good 35mm film.
>>>
>>> The camera in the cell phone is "handy" for some things but not for
>>> images you wish to make full screen on the computer or prints that are 8
>>> X 10 or larger. At least I've never seen one. Some smart phones have
>>> promised to take multiple images and combine them for resolution.
>>>
>>> 73
>>>
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