Oh he can do that, albeit through the mouth. Because Dumb Donkey is a mouth breather, he drools as he types (loses control over other bodily functions, as well). The result is what you see here.
Yes, I would like to see them. Probably better than the Sunday funny paper.
-- Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
That's why he thinks its easy to fill potholes. Unfortunately, his fill is foul.
-- http://improve-usenet.org/index.html aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages. If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you\'re crazy.
Really? Minorities were allowed to use them back then?
I think he is referring to a part of the world that is about to adopt sharia law..
They don't even have phones. Only limb chopping sabers, commissioned by their saber wielding fucktard they think became a god.
: : :Ross Herbert wrote: : :> Since your PC is mains powered and it may not have the required isolation :> between the mains side and the sound card input you can do your own thing using :> an approved 600:600 transformer with 3kV isolation rating to interface the :> telephone line to the sound card input. : :He DOES NOT need a 600 ohm transformer since the input impedance of the sound card :is not 600 ohms !
Since the application is merely detecting signal "voltage" it hardly matters that the secondary impedance of the transformer is 600 ohms and the input impedance of the sound card is more like 10Kohms. The only reason one tries to match impedances is where one needs to maximise "power transfer" and that doesn't apply in this case.
: :It's more likely to be in the tens of kilohms. : :What he really wants is something like a 10k:10k 'line bridging' transformer. In :practice, using a '600 ohm' transformer will probably be ok, but being incorrectly :loaded will degrade the sound quality (freq resonse may be peaky etc). : :Graham :
Not true!
using
sound card
transformer. In
incorrectly
That would work, but a 600 ohm load would give the flattest frequency response, and a -3 dB change would be equal to someone picking up an extension. Some signal loss, but not outside the design limits. The best choice would be a telephone interface like those used for radio stations. They are bi-directional, and allow the host to talk to the listeners, and the caller at the same time. They will work reliably, even if there is a -20 dB change in line level. I have seen it happen when a SLIC feeding a station goes bad. The problem is that they are thousands of dollars for a small system. Sometimes you can find the Dictaphone interface for 911 loggers surplus. They are cheap, and usually work fairly well.
-- http://improve-usenet.org/index.html aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages. If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you\'re crazy.
thing using
the
sound card
transformer. In
incorrectly
Not true. It won't necessarily change the frequency response at all, much less significantly.
Not necessarily! You have no way to know how close it already is to design limits, and therefore you cannot make the assumption that using up the entire "slack" allowed for will not instead put it exactly that far out of specs.
Assuming money is no object, nor is space.
And did you note the price tag on a good one? That is necessarily a non-trivial design. (Try it sometime! They are fun, especially if you want to be able to bridge multiple lines.)
So if you already knew these are not suitable...
-- Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
isolation
thing using
the
sound card
transformer. In
incorrectly
That depends on what you consider significant. Even though the telco bandwidth is limited, there is little reason to make it worse.
So you are saying that there are lines in use that can't have a working extension in use with the main phone? The sound card he intends to use has far more than 3 dB gain for the line level inputs.
I have seen network feeds via Telco plant that were so bad that they hit the building at more than -20 dB. At one they insisted it was leaving their C.O. at 0 dB, but we had to turn everything wide open to get even close to 100% modulation. I used a spare magnetic phono preamp to bring it up closer to 0 dB, and had to put up with the RIAA equalization for the network feed. When people complained, we told them why the network sounded so bad. BTW, that feed was through White Alice.
I'm a former Radio & TV broadcast engineer. Both were considerations, but performance and reliability were more important. Dead air is very, very expensive. It can cost you advertisers as well as listeners. Enough of it can cost you your license.
I have. The design isn't that difficult, but the market is tiny so the engineering costs don't have millions of units to defray the costs. Electron hybrids are a handful of op-amps and the concept has been around for a long time. Try designing a high performance AGC system for tracking satellites. The last one I worked with had 14 op-amps and less than 1.5 mV error over a 0 to 5 volt range. This was used to combine (similar to bridging) two unmatched video sources to a proper 0 dBm output with less than a .01 dB tracking error. That is something you would never try to do with a couple phone lines.
The radio station equipment I mentioned can bridge all the lines, as desired. That is 20 lines or so. Since the interfaces are bi-directional, its simple to do the bridging at the station side by simply connecting them together in any combination. A simple on line/Off line button connects each line to the board. Punching up additional lines also bridges them. Even if the telco lines aren't perfect, it works. Each line can be trimmed for best performance, as long as the telco plant is fairly stable.
The packaging and documentation for niche market equipment can cost more than the actual electronics. The highest cost is still the engineering.
By who's definition? This thread has wandered all over the place.
If you want cheap, some stations with a 1A2 system would take a spare phone and remove the handset. They would connect the receiver terminals to a 200 to 600 ohm input on their console and use the phone to select the line to go live.
That was nothing more than a telephone network across the line, and using the isolated receiver circuit to feed the console. It was common until the '80s when stations wanted cleaner audio and better control of each phone line. Some of the electronic interfaces also allow computer control so the 'talent' can click on a button on the screen with the mouse to select a line. The same way they select commercials, station IDs and PSAs. The screen will list the callers name and information from the call screener, if desired. Click another button and it will display every piece of music in the station's library for listeners request type shows.
-- http://improve-usenet.org/index.html aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages. If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you\'re crazy.
I now have some more information on this.
To quote:
"Studio Engineering for Sound Broadcasting" Illife 1955. Chapter 7 "Programme circuits on Post Office Lines" G Stannard, Bsc A.M.I.E.E - Lines department.
p142. "The distribution of BBC Light Programme to Burghead at the time of writing contains 693 miles of 16mH/1.136m. and the estimated delay distortion relative to 1kc/s is: 50 c/s 50m.sec 100 c/s 9.5m.sec 7 kc/s 7.3 m.sec"
16mH/1.136m describes a loaded line and m, in this case, would be miles. Elsewhere a table gives the following information for this type of line:Weight of conductor 40lb/mile, Approx characteristic impedance 490 ohms, Cut-off frequency 9.3kc/s, maximum useable frequency 7.44kc/s.
The book further goes on to discuss carrier circuits
p131 (Same chapter)
"In 1938 the Post Office began a big expansion in their communication network by laying 12-channel carrier cables. These are low capacitance cables specifically designed for the transmission of frequencies up to 60 kc/s and subsequently up to 120kc/s"
Two schemes are discussed for using carrier circuit lines but they are described (p155) as inferior to circuits obtained by more conventional methods.
-- Stuart Winsor For Barn dances and folk evenings in the Coventry and Warwickshire area See: http://www.barndance.org.uk
Thanks Stuart - this fits exactly with my memories of the time. It was a while back though ...... The BBC now has its own digital audio distribution systems, and no longer requires the widespread use of BT programme circuits.
To reiterate for those who have generated all the heat and the fabulously inaccurate rantings - The programme circuits were BASEBAND AUDIO all the way - amplified en route. As Stuart quotes - carrier is possible, but provides worse noise and distortion standards.
Carrier was not generally used for main UK programme distribution (sorry Floyd - you may be right about American practice, but not UK).
John
Now that was the right, properly worded response to Floyd. Good job.
I wonder where this places the retarded donkey's assertions, if he ever actually made any, other than his rantings. He did claim to have a fairly deep knowledge... that he had a schematic.... somewhere.
It would be nice to see your document posted up in alt.binaries.schematics.electronic, if, that is, you have access to it.
It's a 200 page book and I'm afraid I don't really have the time. Copyright might also be an issue. One or two pages I suppose I could manage but which ones? :-)
My current project is going through hundreds of old electronics magazines and scanning to PDF, stuff that I find of interest.
-- Stuart Winsor For Barn dances and folk evenings in the Coventry and Warwickshire area See: http://www.barndance.org.uk
Gosh, Stuart, why??
I do the exact opposite - if I get an *interesting* PDF, then I print it and store the hard copy.
I just cannot cope with trying to read complex documents on a screen, and the pink highlighter on the screen does not scroll with the page, either :-))
-- Russell http://www.russell-hafter-holidays.co.uk Russell Hafter Holidays E-mail to enquiries at our domain Need a hotel?
Indicative of piss poor grasp of modern computer technology, not to mention quite lame document handling capacity. You don't know how to add a highlight to a doc on screen? Perhaps you need a mini NASCAR scrolling bug screen you can scroll with your document, dipshit?
Bwuahahahahahah!
No, I'm saying it will not *necessarily* change the response. It depends on the transformer and other circuit components. It *might* be a problem, but you said it absolutely would.
Yes. But worse yet, if they do and you put something like that on the line, then they can't! If there were no alternative, it would be acceptable and one would just have to not use it if it caused a problem. But since it is easy to design it to *never* cause level problems, that is exactly the way it should be designed.
Which also amplifies noise too. Bad design...
Network feeds are an entirely different beast than connecting to the PSTN.
You were lucky you could hear it! :-)
Actually, if that was the AFRN feed, you should have been able to cause all sorts of commotion! That was the highest priority circuit in Alaska for the entire life of the White Alice Comm System!
Pass out towels with your sob stories? (It doesn't have anything to do with this tale of woe.)
Oh, goodness, those towels had better be beach size. This is a lot of tear jerking material. (But, alas, other than that wonderful rhythm you make thumping on your chest, it has nothing to do with this particular thread.)
-- Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
It depends on the situation, how long you need it, and if it will be used on a continuing basis. If the telco plant is that flaky, it needed repaired.
I had to do a live remote at the Army base and they refused to set up the copper pair for our feed in time so I took a spare audio board to the site, and some alligator clips. I dialed the cleanest phone line to the station and connected the transformer coupled line output to the phone line, then hung up the phone. The transformer had no trouble with the DC bias, and the feed worked. They threw a fit when they found out, but the General was happy that the feed worked.
Compared to the noise from a carbon microphone?
They are closer to what the OP wants to do.
They only worried about it while it was 'on Alice'. When it went to the old lead clad telco lines it was the military's problem, and they local group didn't care. The only clean phone line to the broadcast complex went to a boiler room at the far end. Maintenance used it when they were there for repairs so it was rarely used. The station's lines all had so much noise that it wasn't funny. Our complaints always got the same response. "That trunk line is to be replaced in five years, so you'll just have to live with it." Some had so much RF problems that the AM radio signal was louder than either party.
Only because you don't want to hear it. If the phone lines are down for long, it cost the telco money, too.
You brought up bridging so get your own towels. Interfaces are a hell of a lot simpler than they were 50 years ago. For instance, Clare has the whole interface on a single IC:
-- http://improve-usenet.org/index.html aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages. If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you\'re crazy.
There is nothing there suggesting the telco plant is flaky or needs repair. It just says they do have design parameter targets, and that good design will adhere to the specifications.
Your point being? (Other than chest pounding?)
It amplifies that too.
Your point being? (Other than chest pounding?)
The OP is talking about the PSTN, only.
So if the problem was the Army (you), why complain about WACS?
Your point being? (Other than chest pounding?)
You are not discussing bridging though (or even VF circuits), so I still don't see any point in all of that nonsense.
Your point being? (Other than chest pounding?)
-- Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
On Mon 29 Dec 15:36, Eeyore wrote
Graham, I must say a better sound card is attractive. I checked out Terratec which you mentioned. Their web site lists the Aureon 5.1 PCI card but it has those potentially noisy 3.5 mm jack sockets.
I assume the noise would be from the build quality of the 3.5 mm jack plug as it seems to usually have a rivetted centre core that could and turn. The contacts in the sockets are also probably very basic.
To see what I would need to do for the balanced cicruit you were recommending I Googled Epanorama and saw this:
In the section called "Interference in the telephone line signal" it refers to a heavy 1 kg choke or transformer! That seems a bit of a non-starter.
I also saw the "DMX 6Fire USB" at Terratec but it seems too spartan and is not cheap at over £150.
So I have also checked out a few alternatives to the Terratec and I mention them at the end of my post to Phil Allison. They are:
(a) a Behringer Xenyx 502 mixer (£32)
(b) an analogue to digital interface Behringer UCA202 for £20
(C) or something which combines the two.
My post about this is at:
news:Xns9B8A15B4A335B74C1H4@216.151.153.41 Google Groups:
-------=======------
Phew! That's a lot of researching!
Is there a simple circuit you know to attach the phone to the PC in a a balanced way?
Any constructive comments would be welcome.
Thank you.
PB
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