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#1
March 25th 06, 08:43 PM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
John,
How about a miniature stereo phono plug? These have 2 signal circuits plus a ground. They're common, they're available in many PCB configurations, and they're cheap. Joe W3JDR "John Wilkinson" wrote in message news  Hi, I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. |
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#2
March 26th 06, 08:08 PM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
Problem with a phono-plug and a clock signal is that you will get reflection
back -- probably much better off with a BNC or SMA connector. "W3JDR" wrote in message news:NXhVf.9224$6%2.4606@trnddc08... John, How about a miniature stereo phono plug? These have 2 signal circuits plus a ground. They're common, they're available in many PCB configurations, and they're cheap. Joe W3JDR "John Wilkinson" wrote in message news Hi, I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. |
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#3
March 26th 06, 09:20 PM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
Hi,
I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. |
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#4
March 26th 06, 10:19 PM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
The author said it was RS-485. This is a 2-wire differential signalling
system. He also wants to use a shield. Hence the need for 3 circuits. I doubt that reflections will play any part in the performance, especially considering that he's using twisted-pair for the signals. This is how CAT5 RS-485 distribution works. Besides, he's talking about a1 MHz presumably steady-state square-wave clock and presumably short board-to-board connection lengths. Joe W3JDR "jack" wrote in message ... Problem with a phono-plug and a clock signal is that you will get reflection back -- probably much better off with a BNC or SMA connector. "W3JDR" wrote in message news:NXhVf.9224$6%2.4606@trnddc08... John, How about a miniature stereo phono plug? These have 2 signal circuits plus a ground. They're common, they're available in many PCB configurations, and they're cheap. Joe W3JDR "John Wilkinson" wrote in message news Hi, I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. |
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#5
March 27th 06, 09:01 AM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
On Sun, 26 Mar 2006 21:19:01 GMT, W3JDR wrote:
The author said it was RS-485. This is a 2-wire differential signalling system. He also wants to use a shield. Hence the need for 3 circuits. I doubt that reflections will play any part in the performance, especially considering that he's using twisted-pair for the signals. This is how CAT5 RS-485 distribution works. Besides, he's talking about a1 MHz presumably steady-state square-wave clock and presumably short board-to-board connection lengths. Joe W3JDR "jack" wrote in message ... Problem with a phono-plug and a clock signal is that you will get reflection back -- probably much better off with a BNC or SMA connector. "W3JDR" wrote in message news:NXhVf.9224$6%2.4606@trnddc08... John, How about a miniature stereo phono plug? These have 2 signal circuits plus a ground. They're common, they're available in many PCB configurations, and they're cheap. Joe W3JDR "John Wilkinson" wrote in message news
Hi,I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. HI, Yes this is a differential signale, so needs 2 connections plus ground for the shield. I have looked for these stereo phono plugs, but to no avail, any idea who stocks them, RS/Farnell numbers. Thanks, John. |
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#6
March 27th 06, 11:28 AM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
John,
Over here we'd just run down to the nearest Radio Shack store, or if we had to mail-order them we'd go to Digikey (www.digikey.com) or Mouser www.mouser.com). Here is a link to a digikey catalog page that shows the different types they carry: http://dkc3.digikey.com/PDF/T061/0304.pdf Also, here is a link to a Digikey search page from which you can narrow your search down to a specific type and stock number: http://www.digikey.com/scripts/DkSea...S&Cat=32440884 If you follow the above link to a specific connector, you'll eventually get to a page that has the manufacturer's web sites and datasheet information. This might help you at least pick a connector type, then go to the manufacturer's web page and find out who stocks the part in your area. Joe W3JDR "John Wilkinson" wrote in message ... On Sun, 26 Mar 2006 21:19:01 GMT, W3JDR wrote: The author said it was RS-485. This is a 2-wire differential signalling system. He also wants to use a shield. Hence the need for 3 circuits. I doubt that reflections will play any part in the performance, especially considering that he's using twisted-pair for the signals. This is how CAT5 RS-485 distribution works. Besides, he's talking about a1 MHz presumably steady-state square-wave clock and presumably short board-to-board connection lengths. Joe W3JDR "jack" wrote in message ... Problem with a phono-plug and a clock signal is that you will get reflection back -- probably much better off with a BNC or SMA connector. "W3JDR" wrote in message news:NXhVf.9224$6%2.4606@trnddc08... John, How about a miniature stereo phono plug? These have 2 signal circuits plus a ground. They're common, they're available in many PCB configurations, and they're cheap. Joe W3JDR "John Wilkinson" wrote in message news
Hi,I have a 1MHz clock that I need to disribute to several boards. I am using RS485 drivers and receivers to do this, along with twisted screened cable. The question is that I need a 2 pole pcb connector that is screened. Does anyone know of such a beast? Thanks, John. HI, Yes this is a differential signale, so needs 2 connections plus ground for the shield. I have looked for these stereo phono plugs, but to no avail, any idea who stocks them, RS/Farnell numbers. Thanks, John. |
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#7
March 27th 06, 11:57 AM
posted to rec.radio.amateur.homebrew
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Connection for clock distribution
Hi
I would use a USB connector and cable. These contain two (possibly three) twisted pair with a shield around them. They are controlled to 93 ohms differential impedance, and do not have significant reflections below 1 Ghz when terminated properly. They are cheap and plentiful, and available in a variety of sizes for PCB mount. Mouser sells a good assortment--I usually go for the 'B' size for PCBs. I use these for an RF differential probe I designed, with good results. There are also lines of shielded telephone connectors and cable available. For a 1 Mhz clock these would do well, and do not have as low an impedance, which might be easier for your 485 drivers to work into. Regards, Glenn |
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