radio interference

I built a serial port temp. sensor years ago based on this fella's work: http://quozl.netrek.org/ts /
And just bought kit 145 from carl's electronics:
http://www.kitsrus.com/pdf/k145.pdf
The unit uses DS1820 temp sensors and connects to the pc serial port. There is a fifty foot run from the computer to the sensor.
My better half made me quit using it because of AM radio interference. There is a constant beep beep beep.
I'm once again in need of 24 X 7 temp. logging. Is there an easy way to salvage this unit? Or am I better off to just start over with some sort of analog unit?
Karl
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wrote:

You could try looping the cable through a ferrite core. http://www.antennex.com/shack/Dec99/beads.htm
jsw
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On 4/16/2011 9:26 AM, Karl Townsend wrote:

Start with the basics. Is the cable shielded with the shields terminated? You should be running shielded twisted pair, and the cable signal lines should be terminated at both ends. Are the circuit boards in a grounded metal enclosure? If the system is shielded, the next step will be to wrap a few turns of the cables around a ferrite attenuator core, as Jim suggests. If it were in my heart and lung machine I would add .1uF monolythic ceramic capacitors to the output of the DTS line at the computer and the input of the voltage regulator on the board. Separation of the data cable and the AM antenna will help. Running the cable close to the ground or in metallic conduit will help. An external AM antenna for the radio (away from the data line) will help.
Kevin Gallimore
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wrote:

You didnt say if it worked....assume it did....
Short of a lot of stuffing around, the clamp on ferrite interference cores are worth a try - then try if the cables you have run have spare conductors, ground them all at each end. Maybe double up on the power one on pin 8 - the thing gets its power from the receiving computer, could be a bit iffy what with voltage drop on your feed cable...
Oh, and BTW Karl - you are aware you are committing a Federal Offense by running an unlicensed radio transmitter causing interference to your wifes radio. Possibly a lot of other radios as well.. Tsk tsk....<G>..
Andrew VK3BFA.
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Andrew VK3BFA wrote:

Same for all those CFL users. /mark in BC
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Mark F wrote:

Those are not "intentional radiators".
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You've missed the point, there is a moral dimension here - its relatively easy to STOP the interference, no need to run off and get a lawyer and claim you got no responsibility. Thought you lot were better than that.
Andrew VK3BFA.
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On Sat, 16 Apr 2011 08:26:42 -0500, Karl Townsend

Buy her a bloody FM radio! Better yet, a sat radio, with none of the farkin' commercials playing all the time.
-- Threee days before Tucson, Howard Dean explained that the tea party movement is "the last gasp of the generation that has trouble with diversity." Rising to the challenge of lowering his reputation and the tone of public discourse, Dean smeared tea partiers as racists: They oppose Obama's agenda, Obama is African-American, ergo...
Let us hope that Dean is the last gasp of the generation of liberals whose default position in any argument is to indict opponents as racists. This McCarthyism of the left -- devoid of intellectual content, unsupported by data -- is a mental tic, not an idea but a tactic for avoiding engagement with ideas. It expresses limitless contempt for the American people, who have reciprocated by reducing liberalism to its current characteristics of electoral weakness and bad sociology. --George Will 14 JAN 2011 Article titled "Tragedies often spark plenty of analysis"
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wrote:

Professor Will appears to have jumped the gun. Here's the latest example:
" [R]espondents were asked whether they agreed with various characterizations of different racial groups. Only 35 percent of those who strongly approve of the tea party agreed that blacks are hardworking, compared with 55 percent of those who strongly disapprove of the tea party. On whether blacks were intelligent, 45 percent of the tea-party supporters agreed, compared with 59 percent of the tea-party opponents. And on the issue of whether blacks were trustworthy, 41 percent of the tea-party supporters agreed, compared with 57 percent of the tea-party opponents.
"The survey, which included about 1,000 respondents in six battleground states (like Michigan and Nevada) and California, found similar margins on questions regarding Latinos."
http://depts.washington.edu/uwiser/mssrp_table.pdf
George tends to fall in love with his own rhetorical skills and to go off half-cocked when he thinks he has a great insight. His "insight" this time appears to be that the Tea Party is the second coming of his beloved Burkean conservatives, with a strong libertarian bent. The evidence is that not everyone in the Tea Party is a racist, but that racists seem to gravitate toward the Tea Party -- something like Muslims and terrorists.
--
Ed Huntress



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wrote:

So those who support the tea party are significantly more likely to hold racist views as compared to those who don't ?
--Wow I never would have guessed !
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wrote:

more likely to show dark roots. You don't really need a fancy study to know the general shape of the answer. d8-)
--
Ed Huntress



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It would be interesting if the same questions were asked about white folks. It could be that members of the Tea Party have a lower opinion about everyone. In fact I would expect members of a group that thinks the government is not hard working, trustworthy, or intelligent, would also think everyone is the same way.
Dan
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wrote:

That's an interesting thought. I'd like to see such a study, too.
--
Ed Huntress



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wrote:

There was study on racism performed in Nov, 2008. About 95% of blacks voted for a black for president over a white. Mikek
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wrote:

So did I.
That's smart. What's dumb is blue-collar white men voting for a washed-up old Republican.
--
Ed Huntress



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wrote:

I'll give you that we didn't have the best candidate, but at least he did believe that America is great country and we have helped the world. The president we have now does not believe in the individual and what we can accomplish when government gets out of the way. I believe a lot of poverty in America is caused by government programs that promote the idea that you don't need to provide for yourself. I believe that the rich provide jobs for most people, and it will hurt the economy if you take more from them. The top 1% pay 38% of all taxes and the bottom 50% pay 2% of taxes. That is messed up. In my opinion if you don't pay taxes you should not have a voice in how those taxes are spent. And I don't want to hear they pay payroll taxes, those are social security taxes are a forced retirement program. Sometimes known as a ponze scheme. I believe that if you are motivated you can provide a comfortable lifestyle and save for you future, and if the government would get out of the way it would be much easier. Our president did say he would raise energy prices and he has done that and if we let him he will raise them more. Have you noticed the rise in your electric bill sense Obama was elected? We need to reduce the public dole rather than add more, as Obama wants to do. It's time for you to grow up and take care of yourself instead of looking to the taxpayers to care for you. Mikek
PS, Karl, how's the 1 wire system problem coming along?
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wrote:

My God. I've never heard anyone who has so completely bought into the whole enchilada. The billions of dollars that the plutocrats have paid to market their bill of goods to you has really paid off.
It isn't worth trying to argue those points because there are so many of them, and you probably wouldn't believe the facts, anyway. But here's one small example of what you'd see if you actually dug into those ideas of yours to see if they hold up in the face of the evidence: The price of electricity has gone *down*, not up, since Obama came into office. But Obama had nothing to do with it.
Average retail price in 2008 was 11.26 cents/kWhr in 2008. So far in 2011, it's 10.99 cents/kWhr.:
http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html (bottom table, "Electric Sales, Revenue and Average Price")
Maybe you're leaving your lights on at night.
Are you an evidence-based kind of guy, or are you one of those who thinks he already knows what all the answers are? If you're the former, we can pick through those things and see what the facts are. If you're the latter, grab a beer and pull up a stool. You have plenty of company here.
--
Ed Huntress



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True in a sense perhaps, but since "most people" happen to live either in India or China NOT the US....

The problem here is we have been taking less from the rich and from the corporations for what's going on nearly three decades now and what's happened instead is that family wage jobs continue to disappear and poverty rates have been increasing for the entire period, except during Clintons term....in addition, US wages overall continue to paint a rather dismal portrait when adjusted for inflation.
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I'm afraid that's more a part of working in a world economy than less taxes for the rich and corporations. When the rest of the world started to catch up with us in technology/production -and- had lower wages, it caused that sucking sound that Perot spoke about. As far as taxing corporations, as you know, we the purchasers pay all those taxes, so if you eliminate corporate taxes we could sell more products overseas (lower prices) and add jobs here. Mikek
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amdx wrote:

Do facts or history ever enter your thought process? Just wondering. The evidence is that they don't.
--
John R. Carroll




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