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Groups > sci.physics > #533801 > unrolled thread
| Started by | RichD <r_delaney2001@yahoo.com> |
|---|---|
| First post | 2015-11-17 10:42 -0800 |
| Last post | 2015-11-25 23:51 +0000 |
| Articles | 20 on this page of 95 — 14 participants |
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long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-17 10:42 -0800
Re: long antenna Odd Bodkin <bodkinodd@gmail.com> - 2015-11-17 12:46 -0600
Re: long antenna Poutnik <poutnik4nntp@gmail.com> - 2015-11-17 20:10 +0100
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 20:28 +0000
Re: long antenna benj <nobody@gmail.com> - 2015-11-17 16:59 -0500
Re: long antenna Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-18 22:56 +0100
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 16:57 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-18 23:15 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 20:42 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 05:29 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-19 08:54 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 18:44 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-22 15:32 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 23:16 +0000
Re: long antenna HVAC <mr.hvac@gmail.com> - 2015-11-19 06:59 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-19 20:02 -0500
Re: long antenna benj <none@gmail.com> - 2015-11-19 01:36 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-17 13:28 -0600
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-17 14:04 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 22:35 +0000
Re: long antenna benj <nobody@gmail.com> - 2015-11-17 19:28 -0500
Re: long antenna Timo <timo@physics.uq.edu.au> - 2015-11-17 17:18 -0800
Re: long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-24 11:39 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-24 15:12 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:21 -0600
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 10:05 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 20:05 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:39 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:46 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:55 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 20:04 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:33 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 22:58 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:11 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:42 +0000
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 11:57 -0800
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 14:52 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 21:12 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:58 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:37 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-26 23:45 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-27 01:01 -0600
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 23:31 -0800
Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:34 -0500
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-27 09:58 -0800
Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:46 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-28 16:42 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-28 22:58 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 07:46 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 19:01 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 14:12 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:43 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:41 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 00:15 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 20:23 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 06:21 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-30 15:22 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:48 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:16 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 23:52 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 19:59 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 02:16 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-30 19:20 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 18:53 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-25 00:08 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 06:13 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-18 16:25 -0800
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-19 16:08 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-20 00:40 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-20 15:51 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 00:34 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-21 14:37 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 19:32 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-22 14:50 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-22 11:27 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:44 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:40 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-23 14:13 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-23 13:00 -0500
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-24 13:40 -0500
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-25 13:44 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-23 18:47 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 19:49 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:36 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 23:00 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 16:17 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 23:35 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-20 20:58 -0500
Re: long antenna benj <none@gmail.com> - 2015-11-19 20:09 -0500
Re: long antenna "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-24 12:51 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-25 00:01 -0500
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-25 15:36 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 23:51 +0000
Page 4 of 5 — ← Prev page 1 2 3 [4] 5 Next page →
| From | gilber34 <fafa@invalid.com> |
|---|---|
| Date | 2015-11-30 19:59 -0600 |
| Message-ID | <n3iuud$r9e$1@speranza.aioe.org> |
| In reply to | #536606 |
On 11/30/2015 5:52 PM, jimp@specsol.spam.sux.com wrote: > gilber34 <fafa@invalid.com> wrote: >> The first was done very cleverly by not trying to come into a dish >>>> perpendicularly like a typical dish antenna or optical mirror, but >>>> building a very low off-axis parabola so the radiation comes in at a >>>> very low angle. Things that are not so reflective straight-on become >>>> very shiny at low angles! Cute! >>>> >>>> And as for accuracy, well that just means that one must use modern >>>> techniques VERY carefully and you can get some passable results even at >>>> x-ray wavelengths. >>> >>> I wonder how much babbling nonsense he would generate if I were to >>> bring up dielectric lens antennas, which work exactly like a magnifying >>> glass given he has already said RF does not work like light and >>> magnifying glasses? >>> >> >> you said that, not me, a dielectric lens change phase across an area, >> just like a reflector, but no, you cannot understand phase, too complex. > > Nope, you said RF doesn't work like a magnifying glass. *your statement* is non-sense "RF doesn't work like a magnifying glass" how does RF go through the specified materials, and at what frequency ? it is not scalable, dude. > >> and it does not "work exactly like a magnifying glass" > > A dielectric lens does. not with RF, RF is 3 kHz to 300 GHz, not light. https://en.wikipedia.org/wiki/Radio_frequency > >> RF is not light, dude. study the nomenclalture first. > > RF and light are the same thing, i.e. electromagnetic energy, at different > frequencies as are gamma rays and X-rays. you are continue misusing common terms, RF referes to Radio Frequency. wiki for it. > >> RF refers to the band of frequencies from about 0.5 MHz to 1Mhz > > Try greater than 0 to low THz. wrong. you haven't got a clue. you are not an RF guy, as any RF guy knows RF refers to a range of frequency, and microwave referes to another range of frequency. you do not know RF at all. Even your ARRL manuel says this, you are to far behind to learn now. > >> the FCC disagrees with you, > > You are clueless. you are troll > > Where do you get the silly nonsense you spout? > > Show me anywhere in electromagnetic theory where there is anything even > remotely like A < frequency < B or shut the hell up. that makes no sense at all, you scrambled eggs. where you find your A and your B ? FCC thinks you need re-education, and to ask for your money back. What are the RF bands ? What are the microwave bands ?
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-12-01 02:16 +0000 |
| Message-ID | <mgcvic-6oa.ln1@mail.specsol.com> |
| In reply to | #536625 |
gilber34 <fafa@invalid.com> wrote: > On 11/30/2015 5:52 PM, jimp@specsol.spam.sux.com wrote: >> gilber34 <fafa@invalid.com> wrote: >>> The first was done very cleverly by not trying to come into a dish >>>>> perpendicularly like a typical dish antenna or optical mirror, but >>>>> building a very low off-axis parabola so the radiation comes in at a >>>>> very low angle. Things that are not so reflective straight-on become >>>>> very shiny at low angles! Cute! >>>>> >>>>> And as for accuracy, well that just means that one must use modern >>>>> techniques VERY carefully and you can get some passable results even at >>>>> x-ray wavelengths. >>>> >>>> I wonder how much babbling nonsense he would generate if I were to >>>> bring up dielectric lens antennas, which work exactly like a magnifying >>>> glass given he has already said RF does not work like light and >>>> magnifying glasses? >>>> >>> >>> you said that, not me, a dielectric lens change phase across an area, >>> just like a reflector, but no, you cannot understand phase, too complex. >> >> Nope, you said RF doesn't work like a magnifying glass. > > *your statement* is non-sense "RF doesn't work like a magnifying glass" Gibberish. A dielectric lens works exactly like a magnifying glass and is defined by the same principals of physics. > how does RF go through the specified materials, and at what frequency ? > it is not scalable, dude. More gibberish. The frequency is whatever it is designed for. >> >>> and it does not "work exactly like a magnifying glass" >> >> A dielectric lens does. > > not with RF, RF is 3 kHz to 300 GHz, not light. > > https://en.wikipedia.org/wiki/Radio_frequency So you have changed your tune as to what part of the electromagetic spectrum is called 'RF' after having looked it up. Next you can look up dielectric antennas in general and the dielectric lens in particular. >>> RF is not light, dude. study the nomenclalture first. >> >> RF and light are the same thing, i.e. electromagnetic energy, at different >> frequencies as are gamma rays and X-rays. > > you are continue misusing common terms, RF referes to Radio Frequency. > wiki for it. Your are continuing to be an idiot. RF and light are the same thing, i.e. electromagnetic energy, at different frequencies as are gamma rays and X-rays. >> >>> RF refers to the band of frequencies from about 0.5 MHz to 1Mhz >> >> Try greater than 0 to low THz. > > wrong. you haven't got a clue. you are not an RF guy, as any RF guy > knows RF refers to a range of frequency, and microwave referes to > another range of frequency. 0 to low THz IS a range of frequencies, idiot. Microwave refers to a subset of the RF spectrum, idiot. > you do not know RF at all. Even your ARRL manuel says this, you are to > far behind to learn now. No, the ARRL manual (sic) does NOT say this, idiot. You haven't a clue what any ARRL book says as you have obviously never read any. >> >>> the FCC disagrees with you, >> >> You are clueless. > > you are troll Nope, just correcting your idiocy. >> >> Where do you get the silly nonsense you spout? >> >> Show me anywhere in electromagnetic theory where there is anything even >> remotely like A < frequency < B or shut the hell up. > > that makes no sense at all, you scrambled eggs. where you find your A > and your B ? You are the one claiming that electromagnetic phenomena has discrete boundarys. Obviously A would be the lower frequency boundary and B the upper frequency boundary, if such a thing existed. > FCC thinks you need re-education, and to ask for your money back. More babbling nonsense. > What are the RF bands ? > What are the microwave bands ? Read some of those ARRL books and find out, idiot. -- Jim Pennino
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| From | benj <none@gmail.com> |
|---|---|
| Date | 2015-11-30 19:20 -0500 |
| Message-ID | <TI57y.231988$fC2.140470@fx03.iad> |
| In reply to | #536556 |
On 11/30/2015 03:48 PM, jimp@specsol.spam.sux.com wrote:
> benj <none@gmail.com> wrote:
>> On 11/30/2015 02:01 PM, jimp@specsol.spam.sux.com wrote:
>>> gilber34 <fafa@invalid.com> wrote:
>>>> On 11/28/2015 4:58 PM, jimp@specsol.spam.sux.com wrote:
>>>>> gilber34 <fafa@invalid.com> wrote:
>>>>>> On 11/27/2015 10:46 AM, benj wrote:
>>>>>>> On 11/27/2015 02:01 AM, gilber34 wrote:
>>>>>>>> On 11/26/2015 10:45 PM, benj wrote:
>>>>>>>>> On 11/26/2015 08:37 PM, jimp@specsol.spam.sux.com wrote:
>>>>>>
>>>>>>>
>>>>>>> perhaps not gamma ray, but you DO know that X-ray parabolic antennas
>>>>>>> exist, right?
>>>>>>
>>>>>> using glancing, paraboioids and hyperboioids, not quite the same as a
>>>>>> dish. but my point was to counter the over generalization that EM
>>>>>> frequency being the same. Still waiting on the size of the 60 HZ dish
>>>>>> for 20 dB gain...
>>>>>
>>>>> Pretty large, but the physical size is irrelevant; the gain of a dish
>>>>> is a function of it's diameter in wavelengths, so the gain of a 3 lambda
>>>>> 60 Hz dish is the same as the gain of a 3 lambda 60 GHz dish.
>>>>
>>>> as usual, WRONG.
>>>
>>> Nope.
>>>
>>> Then why do antenna books have nomographs of dB gain verssus physical
>>> size with straight lines for frequency.
>>>
>>>> the 60Hz dish would be 17,794,063.6 meters wide or 11,056 miles wide or
>>>> 100 times the diameter of the Earth. Impossable to build it at all.
>>>
>>> Not in space given enough time and money.
>>>
>>>> THE PHYSICAL SIZE IS THE ISSUE !
>>>
>>> Nope.
>>>
>>> Physical size only determines the econonomic practicably, not the RF
>>> characteristics.
>>>
>>>> (what size waveguide do you feed a 60 Hz dish with ?)
>>>
>>> You assume due to your utter ignorance of antennas and RF in general
>>> that all dishes are fed with waveguide; they are not. It is very
>>> common to feed dishes in the lower microwave region and below with
>>> coax.
>>>
>>>> your max surface roughness at 60GHz is what ?
>>>
>>> It is perfect because competant people were used to build it and
>>> irrelevant to the fact that antennas scale in frequency.
>>>
>>>> How much beam taper do you illuminate the edges with to avoid backlobes
>>>> at 60GHz? which would pick up the 60HZ earth very well. What would the
>>>> F/B ratio be to pick up a 60Hz craft 1,000,000,000 miles out ?
>>>
>>> The same as at 60 GHz.
>>>
>>>>> The only issue with a dish at gamma or X-ray frquencies is that the
>>>>> dish has to be made of a material that is reflective at those frequencies,
>>>>
>>>> which there are not any for a parabolic dish.
>>>
>>> Which is irrelevant to the fact that antennas scale in frequency.
>>>
>>> If you can find a material that is relective at gamma or X-ray frquencies,
>>> then such a dish will perform just the same as any other dish at any
>>> other frequency with the same diameter in wavelengths.
>>>
>>>> what is the max surface roughness you could have ? (hint: 1/4 lamda and
>>>> how much is that?) can anybody do that yet ?
>>>> so you are WRONG again, find the answer in ARRL, not.
>>>
>>> The requirements would be the same as any other dish at any other frequency
>>> with the same diameter in wavelengths.
>>>
>>> The thing you are utterly unable to understand is that electromagnetic
>>> theory of antennas is frequency independant.
>>>
>>> The practical ability to construct a given antenna may change with
>>> frequency, but the electromagnetic theory does NOT.
>>
>> Exactly correct. And in fact X-ray antennas have been built and used!
>> They are very interesting practical physics.
>> As jimp said the theory works exactly the same as at any frequency!
>>
>> The trick with X-ray antennas is to get reflectivity and achieve the
>> accuracy of figure at the given wavelength.
>>
>> The first was done very cleverly by not trying to come into a dish
>> perpendicularly like a typical dish antenna or optical mirror, but
>> building a very low off-axis parabola so the radiation comes in at a
>> very low angle. Things that are not so reflective straight-on become
>> very shiny at low angles! Cute!
>>
>> And as for accuracy, well that just means that one must use modern
>> techniques VERY carefully and you can get some passable results even at
>> x-ray wavelengths.
>
> I wonder how much babbling nonsense he would generate if I were to
> bring up dielectric lens antennas, which work exactly like a magnifying
> glass given he has already said RF does not work like light and
> magnifying glasses?
>
:-)
--
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-27 18:53 +0000 |
| Message-ID | <5flmic-j8b.ln1@mail.specsol.com> |
| In reply to | #535846 |
gilber34 <fafa@invalid.com> wrote: > On 11/26/2015 10:45 PM, benj wrote: >> On 11/26/2015 08:37 PM, jimp@specsol.spam.sux.com wrote: >>> gilber34 <fafa@invalid.com> wrote: >>>> On >>> Did you mean to say, "do you have Kraus in your library?" >>> >>> If so, yes, and many others, but that doesn't fix your ignorance >>> of RF. >> >> Hey, Gilber34, I actually studied under Kraus himself! What did you >> study? Not much as far as I can tell. Sorry but I have to side with jimp >> here. You haven't a clue. > > cool, you are one of the priveleged, bet that was great too. > I studied under Rau, inventer of JPG encoding, (cosign transform) and > I know RF/uW very well, +patents, got paid big bucks for it too, designs > and systems worldwide, mil and civilian, Old Crow. (big bucks turned > into obama dollars, 50% smaller in size far less in value) So I will > take some to task if they blow it on RF or uW in a large way. > > If anyone wants to stay on subject we could discuss something, but pot > shots are easier, (ya'lls) memories are poor because we have all done a > LOT of things to remember, and posting in a news group is like chalking > on a wall, everybody can grafettie it up as they walk by, and jimp gave > up this time saying over and over "...haven't got a clue"(he's > projecting again, unconcious self referenceing, still looking for that > gamma ray parabolic dish antenna) Most of your stuff was so blazingly ignorant it wasn't worth the effort to comment further. -- Jim Pennino
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| From | benj <none@gmail.com> |
|---|---|
| Date | 2015-11-25 00:08 -0500 |
| Message-ID | <enb5y.116566$ij2.39073@fx08.iad> |
| In reply to | #535160 |
On 11/24/2015 03:04 PM, jimp@specsol.spam.sux.com wrote:
> RichD <r_delaney2001@yahoo.com> wrote:
>> On November 17, Timo wrote:
>>>> The idea that making an antenna longer makes it work better comes from
>>>> AM radios and car whips where the antenna is much much shorter than
>>>> wavelength and in that case making it longer often DOES make it work
>>>> better.
>>>
>>> It can help, even when the antenna is larger than the wavelength:
>>> https://en.wikipedia.org/wiki/Arecibo_Observatory
>>
>> Comparing dish vs. wire antenna, is apples vs. oranges.
>>
>>> But typically one wants to pay more attention to design than just
>>> "long extension wire".
>>
>> More dish area will collect more signal power, but
>> apparently this doesn't apply to a wire.
>
> A dish doesn't collect anything, it concentrates energy to a point.
"Points" are fantasy. They don't exist, Jim.
I know what you mean, but the above statement is wrong even in the
mathematical fantasy. It concentrates the energy down to a smaller
region, not a "point". As Herb would say: Think Fourier transform.
--
___ ___ ___ ___
/\ \ /\ \ /\__\ /\ \
/::\ \ /::\ \ /::| | \:\ \
/:/\:\ \ /:/\:\ \ /:|:| | ___ /::\__\
/::\~\:\__\ /::\~\:\ \ /:/|:| |__ /\ /:/\/__/
/:/\:\ \:|__| /:/\:\ \:\__\ /:/ |:| /\__\ \:\/:/ /
\:\~\:\/:/ / \:\~\:\ \/__/ \/__|:|/:/ / \::/ /
\:\ \::/ / \:\ \:\__\ |:/:/ / \/__/
\:\/:/ / \:\ \/__/ |::/ /
\::/__/ \:\__\ /:/ /
~~ \/__/ \/__/
[toc] | [prev] | [next] | [standalone]
| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-25 06:13 +0000 |
| Message-ID | <h40gic-pqh.ln1@mail.specsol.com> |
| In reply to | #535293 |
benj <none@gmail.com> wrote: > On 11/24/2015 03:04 PM, jimp@specsol.spam.sux.com wrote: >> RichD <r_delaney2001@yahoo.com> wrote: >>> On November 17, Timo wrote: >>>>> The idea that making an antenna longer makes it work better comes from >>>>> AM radios and car whips where the antenna is much much shorter than >>>>> wavelength and in that case making it longer often DOES make it work >>>>> better. >>>> >>>> It can help, even when the antenna is larger than the wavelength: >>>> https://en.wikipedia.org/wiki/Arecibo_Observatory >>> >>> Comparing dish vs. wire antenna, is apples vs. oranges. >>> >>>> But typically one wants to pay more attention to design than just >>>> "long extension wire". >>> >>> More dish area will collect more signal power, but >>> apparently this doesn't apply to a wire. >> >> A dish doesn't collect anything, it concentrates energy to a point. > > "Points" are fantasy. They don't exist, Jim. > I know what you mean, but the above statement is wrong even in the > mathematical fantasy. It concentrates the energy down to a smaller > region, not a "point". As Herb would say: Think Fourier transform. In a theoretically perfect world, you would get a point. Of course the energy density would be infinite, which should be a clue to what happens in the real world. -- Jim Pennino
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| From | "reber g=emc^2" <herbertglazier0@gmail.com> |
|---|---|
| Date | 2015-11-18 16:25 -0800 |
| Message-ID | <fa800ba3-9267-4322-9bf8-862fc9cbdc46@googlegroups.com> |
| In reply to | #533801 |
On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: > During my workout yesterday, I attached a 3 meter > extension to the earphone cord of my radio, as I > wanted to place it at a distance. > The cord is the antenna. > > I was indoors, where the reception is usually crummy. > I figured the longer line should improve performance, > right? No! The reception was barely decipherable. > > Can anyone explain the physics here? > > -- > Rich Better speakers(larger) would be your best bet.TreBert
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| From | "reber g=emc^2" <herbertglazier0@gmail.com> |
|---|---|
| Date | 2015-11-19 16:08 -0800 |
| Message-ID | <89abd246-ce2f-4de3-ad7c-ea252c3c5697@googlegroups.com> |
| In reply to | #533801 |
On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: > During my workout yesterday, I attached a 3 meter > extension to the earphone cord of my radio, as I > wanted to place it at a distance. > The cord is the antenna. > > I was indoors, where the reception is usually crummy. > I figured the longer line should improve performance, > right? No! The reception was barely decipherable. > > Can anyone explain the physics here? > > -- > Rich FM goes through walls better than AM you can get music from Hawaii to Calif.Ham radio goes with AM. TreBert
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-20 00:40 +0000 |
| Message-ID | <9p62ic-29l.ln1@mail.specsol.com> |
| In reply to | #534115 |
reber g=emc^2 <herbertglazier0@gmail.com> wrote: > On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: >> During my workout yesterday, I attached a 3 meter >> extension to the earphone cord of my radio, as I >> wanted to place it at a distance. >> The cord is the antenna. >> >> I was indoors, where the reception is usually crummy. >> I figured the longer line should improve performance, >> right? No! The reception was barely decipherable. >> >> Can anyone explain the physics here? >> >> -- >> Rich > > FM goes through walls better than AM you can get music from Hawaii to Calif.Ham radio goes with AM. TreBert Nonsense. Broadcast AM goes through walls much better than broadcast FM. The HAM radio use of AM is about the same as hunting with a bow and arrow, only used these days by a few nostalgics. -- Jim Pennino
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| From | "reber g=emc^2" <herbertglazier0@gmail.com> |
|---|---|
| Date | 2015-11-20 15:51 -0800 |
| Message-ID | <37ee22b0-bbbe-419e-995d-1fe401582376@googlegroups.com> |
| In reply to | #534121 |
On Thursday, November 19, 2015 at 4:46:06 PM UTC-8, ji...@specsol.spam.sux.com wrote: > reber g=emc^2 <herbertglazier0@gmail.com> wrote: > > On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: > >> During my workout yesterday, I attached a 3 meter > >> extension to the earphone cord of my radio, as I > >> wanted to place it at a distance. > >> The cord is the antenna. > >> > >> I was indoors, where the reception is usually crummy. > >> I figured the longer line should improve performance, > >> right? No! The reception was barely decipherable. > >> > >> Can anyone explain the physics here? > >> > >> -- > >> Rich > > > > FM goes through walls better than AM you can get music from Hawaii to Calif.Ham radio goes with AM. TreBert > > Nonsense. > > Broadcast AM goes through walls much better than broadcast FM. > > The HAM radio use of AM is about the same as hunting with a bow and arrow, > only used these days by a few nostalgics. > > > -- > Jim Pennino Bow an Arrow have lots going for them.AM has lots going for it to cover 1,000s of miles.TreBert
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-21 00:34 +0000 |
| Message-ID | <apq4ic-e71.ln1@mail.specsol.com> |
| In reply to | #534296 |
reber g=emc^2 <herbertglazier0@gmail.com> wrote: > On Thursday, November 19, 2015 at 4:46:06 PM UTC-8, ji...@specsol.spam.sux.com wrote: >> reber g=emc^2 <herbertglazier0@gmail.com> wrote: >> > On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: >> >> During my workout yesterday, I attached a 3 meter >> >> extension to the earphone cord of my radio, as I >> >> wanted to place it at a distance. >> >> The cord is the antenna. >> >> >> >> I was indoors, where the reception is usually crummy. >> >> I figured the longer line should improve performance, >> >> right? No! The reception was barely decipherable. >> >> >> >> Can anyone explain the physics here? >> >> >> >> -- >> >> Rich >> > >> > FM goes through walls better than AM you can get music from Hawaii to Calif.Ham radio goes with AM. TreBert >> >> Nonsense. >> >> Broadcast AM goes through walls much better than broadcast FM. >> >> The HAM radio use of AM is about the same as hunting with a bow and arrow, >> only used these days by a few nostalgics. >> >> >> -- >> Jim Pennino > > Bow an Arrow have lots going for them.AM has lots going for it to cover 1,000s of miles.TreBert The distance coverage of AM broadcast has nothing to do with the modulation method. The bow and arrow, muzzle loading black powder firearms, and AM on the HAM bands all have nostalgia value, but none are mainstream. -- Jim Pennino
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| From | jmfbahciv <See.above@aol.com> |
|---|---|
| Date | 2015-11-21 14:37 +0000 |
| Message-ID | <PM0005250E31882BC7@aca403cc.ipt.aol.com> |
| In reply to | #534309 |
jimp@specsol.spam.sux.com wrote: > reber g=emc^2 <herbertglazier0@gmail.com> wrote: >> On Thursday, November 19, 2015 at 4:46:06 PM UTC-8, ji...@specsol.spam.sux.com wrote: >>> reber g=emc^2 <herbertglazier0@gmail.com> wrote: >>> > On Tuesday, November 17, 2015 at 10:42:09 AM UTC-8, RichD wrote: >>> >> During my workout yesterday, I attached a 3 meter >>> >> extension to the earphone cord of my radio, as I >>> >> wanted to place it at a distance. >>> >> The cord is the antenna. >>> >> >>> >> I was indoors, where the reception is usually crummy. >>> >> I figured the longer line should improve performance, >>> >> right? No! The reception was barely decipherable. >>> >> >>> >> Can anyone explain the physics here? >>> >> >>> >> -- >>> >> Rich >>> > >>> > FM goes through walls better than AM you can get music from Hawaii to Calif.Ham radio goes with AM. TreBert >>> >>> Nonsense. >>> >>> Broadcast AM goes through walls much better than broadcast FM. >>> >>> The HAM radio use of AM is about the same as hunting with a bow and arrow, >>> only used these days by a few nostalgics. >>> >>> >>> -- >>> Jim Pennino >> >> Bow an Arrow have lots going for them.AM has lots going for it to cover 1,000s of miles.TreBert > > The distance coverage of AM broadcast has nothing to do with the modulation > method. > > The bow and arrow, muzzle loading black powder firearms, and AM on the > HAM bands all have nostalgia value, but none are mainstream. <rant on> There are now two kinds of interferences in my house such that I cannot receive AM radio stations. there are devices out in the world which do interfere with AM and other bands. When I worked for a computer manufacturer, we had to comply with FCC rules w.r.t. interference and all of our gear was tested to ensure there was no interference. That no longer seems to be happening. During this past summer, there was interference so that the video card on the computer I'm using was scrambled. I don't buy cable TV. Now that everything is digital broadcasting, I'm having enormous trouble getting the TV to work well. I do not understand digial. With analog, the aerial was moved around until the TV screen cleared up. That doesn't seem to work with digital signals. The same aerial position which worked last night may not work tonight. The same aeiral position which worked an hour ago, may not work right now. So I've ruled out weather conditions. What else could change reception so drastically? <rant off> /BAH
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-21 19:32 +0000 |
| Message-ID | <het6ic-d88.ln1@mail.specsol.com> |
| In reply to | #534367 |
jmfbahciv <See.above@aol.com> wrote: > > <rant on> > > There are now two kinds of interferences in my house such that I cannot > receive AM radio stations. there are devices out in the world which > do interfere with AM and other bands. When I worked for a computer > manufacturer, we had to comply with FCC rules w.r.t. interference > and all of our gear was tested to ensure there was no interference. > That no longer seems to be happening. They still are but there two levels of compliance, essentially industrial and consumer and there are some catches. One example of such a catch is front end over load of receivers which can be fixed by a simple filter but is not included as it costs more money. FYI front end over load is basically when there are strong signals at other frequencies causing limiting in the amplifiers in the front end and nothing gets through or only the very strong signal gets through. TV sets are notorious for that. Radio Shack used to carry a TVI filter for less than $10 which when placed at the antenna end of your TV antenna cable fixed that. They don't seem to be in the Radio Shack catalog anymore, but there are other sources. > During this past summer, there was interference so that the video > card on the computer I'm using was scrambled. That I have never seen in spite of the fact that my HAM antenna is less than 20 feet from the computer that controls the radios. You might try some clamp on ferrite cores on the video cable if it does not have molded in ones already; a big lump somewhere in the cable. > I don't buy cable TV. Now that everything is digital broadcasting, > I'm having enormous trouble getting the TV to work well. I do > not understand digial. With analog, the aerial was moved around > until the TV screen cleared up. That doesn't seem to work with > digital signals. The same aerial position which worked last night > may not work tonight. The same aeiral position which worked an > hour ago, may not work right now. So I've ruled out weather > conditions. What else could change reception so drastically? With analog TV, as signal strength decreased, the reception just got fuzzy until it went away. With digital TV, it is either enough signal to decode or no decoding at all. Also the actual frequencies used shifted up and old TV antennas tended to favor the lower frequencies. TV antennas also tend to corrode and not work as well as when they were new. Also, weather does have a bigger effect at the higher frequencies, mostly if the antenna has to "see" through wet foliage. I would reccomend a new antenna designed for the digital frequency range. In my case, I had to get a new antenna, a TVI filter at the antenna, and a distribution amplifier in the house; multiple TV's. I assume you are using coax cable and not the old twin lead; if not, switch to coax. -- Jim Pennino
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| From | jmfbahciv <See.above@aol.com> |
|---|---|
| Date | 2015-11-22 14:50 +0000 |
| Message-ID | <PM0005252272306D9B@aca41c74.ipt.aol.com> |
| In reply to | #534397 |
jimp@specsol.spam.sux.com wrote: > jmfbahciv <See.above@aol.com> wrote: > >> >> <rant on> >> >> There are now two kinds of interferences in my house such that I cannot >> receive AM radio stations. there are devices out in the world which >> do interfere with AM and other bands. When I worked for a computer >> manufacturer, we had to comply with FCC rules w.r.t. interference >> and all of our gear was tested to ensure there was no interference. >> That no longer seems to be happening. > > They still are but there two levels of compliance, essentially industrial > and consumer and there are some catches. > > One example of such a catch is front end over load of receivers which > can be fixed by a simple filter but is not included as it costs more > money. > > FYI front end over load is basically when there are strong signals at > other frequencies causing limiting in the amplifiers in the front end > and nothing gets through or only the very strong signal gets through. Thanks for the explanation :-). The second AM radio interference appeared last June; my current hypothesis is that some flavor of home security system is interfering but I haven't figured out how to test it. > > TV sets are notorious for that. > > Radio Shack used to carry a TVI filter for less than $10 which when > placed at the antenna end of your TV antenna cable fixed that. > > They don't seem to be in the Radio Shack catalog anymore, but there > are other sources. OK. I'll look into filters. When I lived in Mass., I bought an electric kitchen stove. In order to listen to any AM radio, I had to unplug the stove; filters didn't stop the interference. > >> During this past summer, there was interference so that the video >> card on the computer I'm using was scrambled. > > That I have never seen in spite of the fact that my HAM antenna is > less than 20 feet from the computer that controls the radios. I don't know what was causing it. My hypothesis is that something having to do with road construction was the cause since it stopped right after Labor Day. > > You might try some clamp on ferrite cores on the video cable if > it does not have molded in ones already; a big lump somewhere in > the cable. > >> I don't buy cable TV. Now that everything is digital broadcasting, >> I'm having enormous trouble getting the TV to work well. I do >> not understand digial. With analog, the aerial was moved around >> until the TV screen cleared up. That doesn't seem to work with >> digital signals. The same aerial position which worked last night >> may not work tonight. The same aeiral position which worked an >> hour ago, may not work right now. So I've ruled out weather >> conditions. What else could change reception so drastically? > > With analog TV, as signal strength decreased, the reception just > got fuzzy until it went away. > > With digital TV, it is either enough signal to decode or no decoding > at all. > > Also the actual frequencies used shifted up and old TV antennas > tended to favor the lower frequencies. TV antennas also tend to > corrode and not work as well as when they were new. > > Also, weather does have a bigger effect at the higher frequencies, > mostly if the antenna has to "see" through wet foliage. I understand that. When there is snow on the ground (even though there are leaves on the trees) I have a lot less problems with reception. However, foliage shouldn't affect receiving a signal for an hour or so and then no signal after that. > > I would reccomend a new antenna designed for the digital frequency > range. > > In my case, I had to get a new antenna, a TVI filter at the antenna, > and a distribution amplifier in the house; multiple TV's. > > I assume you are using coax cable and not the old twin lead; if not, > switch to coax. Everything is coax and the antenna is for digital. It is not an outdoor antienna; I had a new roof put on the house and decided I didn't want any holes in it, so the outdoor antenna went away (it was not coax). I simply don't understand digial; no experiments with antenna postiioning works. Some nights (I only have the TV on for a couple hours each night) going into the bathroom can interfere the reception; other nights moving my head while I sit in the chair will interfere; (my chair is on the other side of the antenna w.r.t. the tower). /BAH >
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| From | "reber g=emc^2" <herbertglazier0@gmail.com> |
|---|---|
| Date | 2015-11-22 11:27 -0800 |
| Message-ID | <0b6dcf8e-3e67-4cab-9719-1522c5a6f3a1@googlegroups.com> |
| In reply to | #534552 |
On Sunday, November 22, 2015 at 6:49:49 AM UTC-8, jmfbahciv wrote: > jimp@specsol.spam.sux.com wrote: > > jmfbahciv <See.above@aol.com> wrote: > > > >> > >> <rant on> > >> > >> There are now two kinds of interferences in my house such that I cannot > >> receive AM radio stations. there are devices out in the world which > >> do interfere with AM and other bands. When I worked for a computer > >> manufacturer, we had to comply with FCC rules w.r.t. interference > >> and all of our gear was tested to ensure there was no interference. > >> That no longer seems to be happening. > > > > They still are but there two levels of compliance, essentially industrial > > and consumer and there are some catches. > > > > One example of such a catch is front end over load of receivers which > > can be fixed by a simple filter but is not included as it costs more > > money. > > > > FYI front end over load is basically when there are strong signals at > > other frequencies causing limiting in the amplifiers in the front end > > and nothing gets through or only the very strong signal gets through. > > Thanks for the explanation :-). The second AM radio interference > appeared last June; my current hypothesis is that some flavor of > home security system is interfering but I haven't figured out how to > test it. > > > > TV sets are notorious for that. > > > > Radio Shack used to carry a TVI filter for less than $10 which when > > placed at the antenna end of your TV antenna cable fixed that. > > > > They don't seem to be in the Radio Shack catalog anymore, but there > > are other sources. > > OK. I'll look into filters. When I lived in Mass., I bought an > electric kitchen stove. In order to listen to any AM radio, I had > to unplug the stove; filters didn't stop the interference. > > > > >> During this past summer, there was interference so that the video > >> card on the computer I'm using was scrambled. > > > > That I have never seen in spite of the fact that my HAM antenna is > > less than 20 feet from the computer that controls the radios. > > I don't know what was causing it. My hypothesis is that something > having to do with road construction was the cause since it stopped > right after Labor Day. > > > > You might try some clamp on ferrite cores on the video cable if > > it does not have molded in ones already; a big lump somewhere in > > the cable. > > > >> I don't buy cable TV. Now that everything is digital broadcasting, > >> I'm having enormous trouble getting the TV to work well. I do > >> not understand digial. With analog, the aerial was moved around > >> until the TV screen cleared up. That doesn't seem to work with > >> digital signals. The same aerial position which worked last night > >> may not work tonight. The same aeiral position which worked an > >> hour ago, may not work right now. So I've ruled out weather > >> conditions. What else could change reception so drastically? > > > > With analog TV, as signal strength decreased, the reception just > > got fuzzy until it went away. > > > > With digital TV, it is either enough signal to decode or no decoding > > at all. > > > > Also the actual frequencies used shifted up and old TV antennas > > tended to favor the lower frequencies. TV antennas also tend to > > corrode and not work as well as when they were new. > > > > Also, weather does have a bigger effect at the higher frequencies, > > mostly if the antenna has to "see" through wet foliage. > > I understand that. When there is snow on the ground (even though > there are leaves on the trees) I have a lot less problems with > reception. However, foliage shouldn't affect receiving a signal > for an hour or so and then no signal after that. > > > > I would reccomend a new antenna designed for the digital frequency > > range. > > > > In my case, I had to get a new antenna, a TVI filter at the antenna, > > and a distribution amplifier in the house; multiple TV's. > > > > I assume you are using coax cable and not the old twin lead; if not, > > switch to coax. > > Everything is coax and the antenna is for digital. It is not > an outdoor antienna; I had a new roof put on the house and > decided I didn't want any holes in it, so the outdoor antenna > went away (it was not coax). > > I simply don't understand digial; no experiments with antenna > postiioning works. Some nights (I only have the TV on for > a couple hours each night) going into the bathroom can > interfere the reception; other nights moving my head while > I sit in the chair will interfere; (my chair is on the other > side of the antenna w.r.t. the tower). > > /BAH > > > It begs this question "ARE TWO ANTENNES" better than one? I say one for AM and a loop for FM.To pick up space radio waves we use 6 big dishes.and in Chily we have that great dish using a meteorite crater. Feynman told us his swimming pool surface was a great receiver.When Feynman spoke it was best to listen.TreBert
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-22 19:44 +0000 |
| Message-ID | <8ii9ic-kah.ln1@mail.specsol.com> |
| In reply to | #534587 |
reber g=emc^2 <herbertglazier0@gmail.com> wrote: > It begs this question "ARE TWO ANTENNES" better than one? I say one for AM and a loop for FM.To pick up space radio waves we use 6 big dishes.and in Chily we have that great dish using a meteorite crater. Feynman told us his swimming pool surface was a great receiver.When Feynman spoke it was best to listen.TreBert I see someone has been abusing the Bud Light again. -- Jim Pennino
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2015-11-22 19:40 +0000 |
| Message-ID | <t9i9ic-kah.ln1@mail.specsol.com> |
| In reply to | #534552 |
jmfbahciv <See.above@aol.com> wrote: > jimp@specsol.spam.sux.com wrote: > Thanks for the explanation :-). The second AM radio interference > appeared last June; my current hypothesis is that some flavor of > home security system is interfering but I haven't figured out how to > test it. There are all sorts of things that will interfere with AM broadcast. There is currently a brouhaha over home improvement stores selling industrial fluorescent light ballasts that are not marked as such and are being put into homes. These ballasts generate huge amounts of RFI, which is fine for the industrial environment. Some common sources of RFI: fluorescent lights, furnace ignitors, electric fences, computer and networking systems, Uninterruptible Power Supplies, motorized exercise equipment, bad wiring, grow lights. Use a battery powered AM radio as a sniffer and you may be able to find the source. Try turning anything you may suspece off and on. > OK. I'll look into filters. When I lived in Mass., I bought an > electric kitchen stove. In order to listen to any AM radio, I had > to unplug the stove; filters didn't stop the interference. Nope, not much you can do about that except complain BOTH to the manufacturer and the FCC. > I don't know what was causing it. My hypothesis is that something > having to do with road construction was the cause since it stopped > right after Labor Day. Really weird. > I understand that. When there is snow on the ground (even though > there are leaves on the trees) I have a lot less problems with > reception. However, foliage shouldn't affect receiving a signal > for an hour or so and then no signal after that. That is just probably marginal propagation, a better antenna should cure that. > Everything is coax and the antenna is for digital. It is not > an outdoor antienna; I had a new roof put on the house and > decided I didn't want any holes in it, so the outdoor antenna > went away (it was not coax). > > I simply don't understand digial; no experiments with antenna > postiioning works. Some nights (I only have the TV on for > a couple hours each night) going into the bathroom can > interfere the reception; other nights moving my head while > I sit in the chair will interfere; (my chair is on the other > side of the antenna w.r.t. the tower). It is marginal signal propagation and being disturbed by things around the house. I'm afraid the only solution for TV is a real, outside antenna with coax. If you are dead set against holes in the roof, then a pole and an eve bracket. -- Jim Pennino
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| From | jmfbahciv <See.above@aol.com> |
|---|---|
| Date | 2015-11-23 14:13 +0000 |
| Message-ID | <PM00052535E3A4AF8D@aca41148.ipt.aol.com> |
| In reply to | #534593 |
jimp@specsol.spam.sux.com wrote: > jmfbahciv <See.above@aol.com> wrote: >> jimp@specsol.spam.sux.com wrote: > >> Thanks for the explanation :-). The second AM radio interference >> appeared last June; my current hypothesis is that some flavor of >> home security system is interfering but I haven't figured out how to >> test it. > > There are all sorts of things that will interfere with AM broadcast. > > There is currently a brouhaha over home improvement stores selling > industrial fluorescent light ballasts that are not marked as such > and are being put into homes. These ballasts generate huge amounts > of RFI, which is fine for the industrial environment. > > Some common sources of RFI: fluorescent lights, furnace ignitors, > electric fences, computer and networking systems, Uninterruptible Power > Supplies, motorized exercise equipment, bad wiring, grow lights. > > Use a battery powered AM radio as a sniffer and you may be able to > find the source. Try turning anything you may suspece off and on. I know it's not in the house. Some day, I'll take my radio and try to triangulate the first interference. I don't know how to investigate the second interference since the sound is constant and is turned off/on early in the morning. > >> OK. I'll look into filters. When I lived in Mass., I bought an >> electric kitchen stove. In order to listen to any AM radio, I had >> to unplug the stove; filters didn't stop the interference. > > Nope, not much you can do about that except complain BOTH to the > manufacturer and the FCC. I did complain to the stove manufacturer; the comment I got back from the tech is that "noone listens to AM radio anymore". > >> I don't know what was causing it. My hypothesis is that something >> having to do with road construction was the cause since it stopped >> right after Labor Day. > > Really weird. Yea. note it's just a hypothesis but it's the only thing I can think of which is seasonal to match the dates of the problem. > >> I understand that. When there is snow on the ground (even though >> there are leaves on the trees) I have a lot less problems with >> reception. However, foliage shouldn't affect receiving a signal >> for an hour or so and then no signal after that. > > That is just probably marginal propagation, a better antenna should > cure that. > >> Everything is coax and the antenna is for digital. It is not >> an outdoor antienna; I had a new roof put on the house and >> decided I didn't want any holes in it, so the outdoor antenna >> went away (it was not coax). >> >> I simply don't understand digial; no experiments with antenna >> postiioning works. Some nights (I only have the TV on for >> a couple hours each night) going into the bathroom can >> interfere the reception; other nights moving my head while >> I sit in the chair will interfere; (my chair is on the other >> side of the antenna w.r.t. the tower). > > It is marginal signal propagation and being disturbed by things > around the house. I assumed that but shouldn't the disturbances be constant and reproducible w.r.t. position? That's one of the things which puzzles me. > > I'm afraid the only solution for TV is a real, outside antenna > with coax. > > If you are dead set against holes in the roof, then a pole and > an eve bracket. Yea :-( Putting up an outside antenna doesn't guarantee reception if this palce in the midst of an interference whirlwind, especially if I'm in the eye. Anyway Congress is on my big shit list for selling off the analog. /BAH
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| From | benj <none@gmail.com> |
|---|---|
| Date | 2015-11-23 13:00 -0500 |
| Message-ID | <2vI4y.121236$dc2.13006@fx24.iad> |
| In reply to | #534782 |
On 11/23/2015 09:13 AM, jmfbahciv wrote:
> jimp@specsol.spam.sux.com wrote:
>> jmfbahciv <See.above@aol.com> wrote:
>>> jimp@specsol.spam.sux.com wrote:
>>
>>> Thanks for the explanation :-). The second AM radio interference
>>> appeared last June; my current hypothesis is that some flavor of
>>> home security system is interfering but I haven't figured out how to
>>> test it.
>>
>> There are all sorts of things that will interfere with AM broadcast.
>>
>> There is currently a brouhaha over home improvement stores selling
>> industrial fluorescent light ballasts that are not marked as such
>> and are being put into homes. These ballasts generate huge amounts
>> of RFI, which is fine for the industrial environment.
>>
>> Some common sources of RFI: fluorescent lights, furnace ignitors,
>> electric fences, computer and networking systems, Uninterruptible Power
>> Supplies, motorized exercise equipment, bad wiring, grow lights.
>>
>> Use a battery powered AM radio as a sniffer and you may be able to
>> find the source. Try turning anything you may suspece off and on.
>
> I know it's not in the house. Some day, I'll take my radio and
> try to triangulate the first interference. I don't know how to
> investigate the second interference since the sound is constant
> and is turned off/on early in the morning.
>
>>
>>> OK. I'll look into filters. When I lived in Mass., I bought an
>>> electric kitchen stove. In order to listen to any AM radio, I had
>>> to unplug the stove; filters didn't stop the interference.
>>
>> Nope, not much you can do about that except complain BOTH to the
>> manufacturer and the FCC.
>
> I did complain to the stove manufacturer; the comment I got back
> from the tech is that "noone listens to AM radio anymore".
>
>>
>>> I don't know what was causing it. My hypothesis is that something
>>> having to do with road construction was the cause since it stopped
>>> right after Labor Day.
>>
>> Really weird.
>
> Yea. note it's just a hypothesis but it's the only thing I can
> think of which is seasonal to match the dates of the problem.
>>
>>> I understand that. When there is snow on the ground (even though
>>> there are leaves on the trees) I have a lot less problems with
>>> reception. However, foliage shouldn't affect receiving a signal
>>> for an hour or so and then no signal after that.
>>
>> That is just probably marginal propagation, a better antenna should
>> cure that.
>>
>>> Everything is coax and the antenna is for digital. It is not
>>> an outdoor antienna; I had a new roof put on the house and
>>> decided I didn't want any holes in it, so the outdoor antenna
>>> went away (it was not coax).
>>>
>>> I simply don't understand digial; no experiments with antenna
>>> postiioning works. Some nights (I only have the TV on for
>>> a couple hours each night) going into the bathroom can
>>> interfere the reception; other nights moving my head while
>>> I sit in the chair will interfere; (my chair is on the other
>>> side of the antenna w.r.t. the tower).
>>
>> It is marginal signal propagation and being disturbed by things
>> around the house.
>
> I assumed that but shouldn't the disturbances be constant and
> reproducible w.r.t. position? That's one of the things which
> puzzles me.
>>
>> I'm afraid the only solution for TV is a real, outside antenna
>> with coax.
>>
>> If you are dead set against holes in the roof, then a pole and
>> an eve bracket.
>
> Yea :-( Putting up an outside antenna doesn't guarantee reception
> if this palce in the midst of an interference whirlwind, especially
> if I'm in the eye.
>
> Anyway Congress is on my big shit list for selling off the analog.
>
> /BAH
Well, yes and no. The new system really gives fine images when it's
working but it tends to cut out a lot. I live downtown and in the old
days the UHF channels (PBS) were always a mess. The signal was strong,
but bounced among the tall buildings creating havoc. Never got a decent
picture. Now video is just prime, but tends to cut in and out for no
apparent reason. The more things change.
I also had a bad AM noise here. It would come and go. I tried using the
portable radio to track it, but failed. It was clearly in the
neighborhood and got weaker as you went further away, but was
transmitted all through the power distribution system so you couldn't
pinpoint it. My best guess was it was an industrial welder of some sort
in the neighborhood, but I never found it. Eventually as industry moved
out, the noise went with it.
Note that if some item is creating interference, you can complain to the
FCC and they will require the owner (for industry) or the manufacturer
to fix the problem. Telling you "nobody listens to AM" is not good
enough. They won't have to fix all the ones they make, but they will
have to come and install whatever filters it takes to solve YOUR problem.
Same goes for jimp's Ham radio. If he's getting into his neighbor's TV
or radio, FCC will make him go and provide filters, advice, etc. to fix
the problem. Mostly hams are happy to do this and keep good relations
with the community.
--
___ ___ ___ ___
/\ \ /\ \ /\__\ /\ \
/::\ \ /::\ \ /::| | \:\ \
/:/\:\ \ /:/\:\ \ /:|:| | ___ /::\__\
/::\~\:\__\ /::\~\:\ \ /:/|:| |__ /\ /:/\/__/
/:/\:\ \:|__| /:/\:\ \:\__\ /:/ |:| /\__\ \:\/:/ /
\:\~\:\/:/ / \:\~\:\ \/__/ \/__|:|/:/ / \::/ /
\:\ \::/ / \:\ \:\__\ |:/:/ / \/__/
\:\/:/ / \:\ \/__/ |::/ /
\::/__/ \:\__\ /:/ /
~~ \/__/ \/__/
[toc] | [prev] | [next] | [standalone]
| From | jmfbahciv <See.above@aol.com> |
|---|---|
| Date | 2015-11-24 13:20 +0000 |
| Message-ID | <PM0005254977CE6C61@aca4008d.ipt.aol.com> |
| In reply to | #534835 |
benj wrote: > On 11/23/2015 09:13 AM, jmfbahciv wrote: >> jimp@specsol.spam.sux.com wrote: >>> jmfbahciv <See.above@aol.com> wrote: >>>> jimp@specsol.spam.sux.com wrote: >>> >>>> Thanks for the explanation :-). The second AM radio interference >>>> appeared last June; my current hypothesis is that some flavor of >>>> home security system is interfering but I haven't figured out how to >>>> test it. >>> >>> There are all sorts of things that will interfere with AM broadcast. >>> >>> There is currently a brouhaha over home improvement stores selling >>> industrial fluorescent light ballasts that are not marked as such >>> and are being put into homes. These ballasts generate huge amounts >>> of RFI, which is fine for the industrial environment. >>> >>> Some common sources of RFI: fluorescent lights, furnace ignitors, >>> electric fences, computer and networking systems, Uninterruptible Power >>> Supplies, motorized exercise equipment, bad wiring, grow lights. >>> >>> Use a battery powered AM radio as a sniffer and you may be able to >>> find the source. Try turning anything you may suspece off and on. >> >> I know it's not in the house. Some day, I'll take my radio and >> try to triangulate the first interference. I don't know how to >> investigate the second interference since the sound is constant >> and is turned off/on early in the morning. >> >>> >>>> OK. I'll look into filters. When I lived in Mass., I bought an >>>> electric kitchen stove. In order to listen to any AM radio, I had >>>> to unplug the stove; filters didn't stop the interference. >>> >>> Nope, not much you can do about that except complain BOTH to the >>> manufacturer and the FCC. >> >> I did complain to the stove manufacturer; the comment I got back >> from the tech is that "noone listens to AM radio anymore". >> >>> >>>> I don't know what was causing it. My hypothesis is that something >>>> having to do with road construction was the cause since it stopped >>>> right after Labor Day. >>> >>> Really weird. >> >> Yea. note it's just a hypothesis but it's the only thing I can >> think of which is seasonal to match the dates of the problem. >>> >>>> I understand that. When there is snow on the ground (even though >>>> there are leaves on the trees) I have a lot less problems with >>>> reception. However, foliage shouldn't affect receiving a signal >>>> for an hour or so and then no signal after that. >>> >>> That is just probably marginal propagation, a better antenna should >>> cure that. >>> >>>> Everything is coax and the antenna is for digital. It is not >>>> an outdoor antienna; I had a new roof put on the house and >>>> decided I didn't want any holes in it, so the outdoor antenna >>>> went away (it was not coax). >>>> >>>> I simply don't understand digial; no experiments with antenna >>>> postiioning works. Some nights (I only have the TV on for >>>> a couple hours each night) going into the bathroom can >>>> interfere the reception; other nights moving my head while >>>> I sit in the chair will interfere; (my chair is on the other >>>> side of the antenna w.r.t. the tower). >>> >>> It is marginal signal propagation and being disturbed by things >>> around the house. >> >> I assumed that but shouldn't the disturbances be constant and >> reproducible w.r.t. position? That's one of the things which >> puzzles me. >>> >>> I'm afraid the only solution for TV is a real, outside antenna >>> with coax. >>> >>> If you are dead set against holes in the roof, then a pole and >>> an eve bracket. >> >> Yea :-( Putting up an outside antenna doesn't guarantee reception >> if this palce in the midst of an interference whirlwind, especially >> if I'm in the eye. >> >> Anyway Congress is on my big shit list for selling off the analog. >> >> /BAH > > Well, yes and no. The new system really gives fine images when it's > working but it tends to cut out a lot. I live downtown and in the old > days the UHF channels (PBS) were always a mess. The signal was strong, > but bounced among the tall buildings creating havoc. Never got a decent > picture. Now video is just prime, but tends to cut in and out for no > apparent reason. The more things change. > > I also had a bad AM noise here. It would come and go. I tried using the > portable radio to track it, but failed. It was clearly in the > neighborhood and got weaker as you went further away, but was > transmitted all through the power distribution system so you couldn't > pinpoint it. My best guess was it was an industrial welder of some sort > in the neighborhood, but I never found it. Eventually as industry moved > out, the noise went with it. I never thought of a welder. That could be in anybody's garage. But if it were a welder, wouldn't the interference be gone during the night? > > Note that if some item is creating interference, you can complain to the > FCC and they will require the owner (for industry) or the manufacturer > to fix the problem. Telling you "nobody listens to AM" is not good > enough. They won't have to fix all the ones they make, but they will > have to come and install whatever filters it takes to solve YOUR problem. they did try a filter. It didn't work and they gave up. > > Same goes for jimp's Ham radio. If he's getting into his neighbor's TV > or radio, FCC will make him go and provide filters, advice, etc. to fix > the problem. Mostly hams are happy to do this and keep good relations > with the community. Legal hams are willing; the problems are the illegal hams. Stores sell lots of "toys" which create havoc. Lasers and drones have been making the news lately. /BAH
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