On Thu, 05 Nov 2015 00:12:17 +0000, Stephen wrote:

> On 11/4/2015 10:53 PM, Jim Henderson wrote:
>> On Wed, 04 Nov 2015 22:14:15 +0000, Stephen wrote:
>>
>>>> Could be - generally a harmonic frequency can cause weirdness as well
>>>> -
>>>> I
>>>> was more talking about why it's lines and not just snow.  The
>>>> proximity of the transmitter to the "receiver" is what causes that.
>>>>
>>>>
>>>   From the little I know only having worked, with Comms guys. You are
>>> right but then you could tell me anything. It is all magic to me.
>>> They even told me that our phone calls were bounced off the sky and
>>> the sea. And I believed them.
>>
>> Well, I do have a radio license. ;)
>>
>>
> So do I. Albeit the lowest level (RT). I could use a marine radio on a
> fishing vessel or stand in for the RO on an Oil Rig.

I thought you did - so I was a little surprised. :)

>> But that's the reason that proximity to the transmission point for the
>> EM waves matters - and a closer but power power (at transmission point)
>> overpower a signal that's farther away but stronger.  With a 5W
>> transmitter that's not well filtered, an amateur radio operator can
>> disrupt commercial radio (AM/FM) and TV (VHF/UHF) transmissions quite
>> significantly.  Every amateur radio operator has to learn at least a
>> little about this in the US, because we're responsible for dealing with
>> harmful interference we might cause with our gear.
>>
>>
> It is quite a fearsome exam. With Morse code and regulations.

Code isn't required in the US any more - they dropped it out of (as I 
understand it) fear that not enough people would join the hobby to 
justify the spectrum use.

>> Even with well-filtered equipment, though, if I put the transmission
>> source for my radio right next to a computer monitor or CRT display, I
>> can cause some interference.
>>
>>
> Don't forget the cable. Bad connections can cause reflections. ;-)

Oh yes, absolutely.  I also tend to pick up RF from my PCs on my 
headphones (the ones plugged into the PC), even with a proper ground.

Jim



-- 
"I learned long ago, never to wrestle with a pig. You get dirty, and 
besides, the pig likes it." - George Bernard Shaw

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