Re: [time-nuts] altinex switches
Hi Robert, The only way it would make sense to make the center pin diameter smaller on a 75 ohm BNC is if the center section of the connector has dielectric in it. So, I would venture then that if you find a 75 ohm BNC that has dielectric in the mating area, around the pin, it will be a problem. The original coax illustrates this action. Some of the earliest commercial coax was air insulated, and had optimally sized center and shield diameters for low loss power transmission. Which results in 75 ohm impedance. It was a dodgy affair, as it had very thin lucite disks every foot, or so, that kept the center conductor centered in the shield. This worked ok for rigid coax, and even semi-rigid coax where large radius arcs, over long runs, are possible... like on an antenna tower, or a intercontinental under sea telephone trunk cable... At some point, it became desirable to make short flexible runs of coax, WWII as I recall, and the disk scheme wasn't optimal, so the coax was entirely filled with polyethylene plastic, and because of the dielectric constant of the polyethylene, the 75 ohm air dielectric impedance dropped to 50 ohm. The loss went way up, but flexibility trumped loss in short pigtails for interconnecting cables, and 50 ohm became popular RG-8 coax was born. -Chuck Harris Robert Atkinson wrote: Hi Chuck, some early 75R BNC designs did use a smaller diameter center contact. The 75R male can make intermittent contact when used with a worn or top of limit 50R female. The 75R female can be damaged for use with the small contact male if used with a 50R or large contact 75R male. The do exist, but are pretty rare. A lot got changed out as faulty. I've not seen one on any modern (last 20 years) equipment. Robert G8RPI. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Hi Using common WWII coax materials, 75 ohms is roughly the minimum loss per foot design. 50 ohms is the maximum power handling design. The low loss / high power duality is what still has us matching transmitters into 50 ohms and running cable TV at 75 ohms. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Friday, February 22, 2013 9:40 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] altinex switches Hi Robert, The only way it would make sense to make the center pin diameter smaller on a 75 ohm BNC is if the center section of the connector has dielectric in it. So, I would venture then that if you find a 75 ohm BNC that has dielectric in the mating area, around the pin, it will be a problem. The original coax illustrates this action. Some of the earliest commercial coax was air insulated, and had optimally sized center and shield diameters for low loss power transmission. Which results in 75 ohm impedance. It was a dodgy affair, as it had very thin lucite disks every foot, or so, that kept the center conductor centered in the shield. This worked ok for rigid coax, and even semi-rigid coax where large radius arcs, over long runs, are possible... like on an antenna tower, or a intercontinental under sea telephone trunk cable... At some point, it became desirable to make short flexible runs of coax, WWII as I recall, and the disk scheme wasn't optimal, so the coax was entirely filled with polyethylene plastic, and because of the dielectric constant of the polyethylene, the 75 ohm air dielectric impedance dropped to 50 ohm. The loss went way up, but flexibility trumped loss in short pigtails for interconnecting cables, and 50 ohm became popular RG-8 coax was born. -Chuck Harris Robert Atkinson wrote: Hi Chuck, some early 75R BNC designs did use a smaller diameter center contact. The 75R male can make intermittent contact when used with a worn or top of limit 50R female. The 75R female can be damaged for use with the small contact male if used with a 50R or large contact 75R male. The do exist, but are pretty rare. A lot got changed out as faulty. I've not seen one on any modern (last 20 years) equipment. Robert G8RPI. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Actually max power is around 30 ohms. Fifty ohms was a compromise. Here is a good paper on coax design. http://www.google.com/url?sa=trct=jq=coax%20max%20power%20impedancesource=webcd=1sqi=2ved=0CC8QFjAAurl=http%3A%2F%2Fmy.ece.ucsb.edu%2FYork%2FBobsclass%2F144A%2FHandouts%2FWhy50ohm.pdfei=3JwnUcb0MdDy0wHJxoDQDwusg=AFQjCNH-RX8ULC4nXT7lAs2qgQlYIy-HBQ Regards, Tom - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Friday, February 22, 2013 11:11 AM Subject: Re: [time-nuts] altinex switches Hi Using common WWII coax materials, 75 ohms is roughly the minimum loss per foot design. 50 ohms is the maximum power handling design. The low loss / high power duality is what still has us matching transmitters into 50 ohms and running cable TV at 75 ohms. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Friday, February 22, 2013 9:40 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] altinex switches Hi Robert, The only way it would make sense to make the center pin diameter smaller on a 75 ohm BNC is if the center section of the connector has dielectric in it. So, I would venture then that if you find a 75 ohm BNC that has dielectric in the mating area, around the pin, it will be a problem. The original coax illustrates this action. Some of the earliest commercial coax was air insulated, and had optimally sized center and shield diameters for low loss power transmission. Which results in 75 ohm impedance. It was a dodgy affair, as it had very thin lucite disks every foot, or so, that kept the center conductor centered in the shield. This worked ok for rigid coax, and even semi-rigid coax where large radius arcs, over long runs, are possible... like on an antenna tower, or a intercontinental under sea telephone trunk cable... At some point, it became desirable to make short flexible runs of coax, WWII as I recall, and the disk scheme wasn't optimal, so the coax was entirely filled with polyethylene plastic, and because of the dielectric constant of the polyethylene, the 75 ohm air dielectric impedance dropped to 50 ohm. The loss went way up, but flexibility trumped loss in short pigtails for interconnecting cables, and 50 ohm became popular RG-8 coax was born. -Chuck Harris Robert Atkinson wrote: Hi Chuck, some early 75R BNC designs did use a smaller diameter center contact. The 75R male can make intermittent contact when used with a worn or top of limit 50R female. The 75R female can be damaged for use with the small contact male if used with a 50R or large contact 75R male. The do exist, but are pretty rare. A lot got changed out as faulty. I've not seen one on any modern (last 20 years) equipment. Robert G8RPI. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Don; Yes, that seemed to be where I was headed, too. Thanks for responding. JimT Sent from *my* galaxy (Nexus). On Feb 21, 2013 9:26 PM, Don Latham d...@montana.com wrote: Hi Jim: I had to make up a little 3-pin to 9-pin adapter using loose pins. It just kinda hangs there... Don James Tucker Don; I got one of those switchs;*very* nice product, great price. Wish I'd bought two! Do you have a reference for the mating connector for the RS232 by any chance? JimT Sent from *my* galaxy (Nexus). On Feb 21, 2013 4:13 PM, Don Latham d...@montana.com wrote: I don't have the manual source offhand, but it will be in my msg archived. The RS232 does respond, and can also be used to control the unit I have. I got a nice note from the seller; apparently the time-nuts snatched these units up in less than a day...and it was the seller who put me on to the manual, a typical Google got me nothing. I'll be home next week, and can supply the manual URL then if you can't find it. Don Robert LaJeunesse I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
I picked up two of these units and they were a very good deal. Don, thanks for finding and reporting them. I wish I had picked up a few more of them. Inside, there is a four output switching supply with +/-12 and +/-5 volts. If it were possible to cut away some of the main board that includes the input modules, there would be enough room to install a GPSDO. This would make for a house standard with up to 16 buffered outputs. Did any of you find any documentation for these units? The control of the device can be done using the two buttons on the rear of the unit. A single input can be selected and a GPSDO 10 MHz fed in to that input. Multiple outputs are selected by first stepping to a channel then pushing in and holding the output button for a few seconds. It is possible to have a single input drive all the outputs with no loss. Regards, Tom - Original Message - From: Don Latham d...@montana.com To: time nuts time-nuts@febo.com Sent: Monday, February 11, 2013 8:59 PM Subject: [time-nuts] altinex switches I bought a couple of 180986059633 switches. The manual is at: http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%20Run%20(HR)%20Series.pdf You get 8 inputs switchable to 12 outputs IN ANY COMBO. meaning it can be a 12 output distribution amp. isolation amps all round, and either 200 or 300 MHz bandwidth. dc coupled, have a look. There are some left. Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] altinex switches
I haven't looked any further but the daughter boards in the unit have 75 ohm resistors which I'm guessing determines the input/output impedance of the unit. If that's the case it should be easy to switch it to 50 ohms although it may not make any real difference. -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Arthur the video equipment is 75 ohms. This is time-nuttery after all so they do make a difference. Small. But I will never change my 75 ohm resistors out not worth the time and effort by the way I also use 75 ohm cable for Freq distro. But if someone really has nothing better to do then sure change those pesky 1% resistors out. :-) Regards Paul WB8TSL On Thu, Feb 21, 2013 at 3:57 PM, Arthur Dent golgarfrinc...@yahoo.comwrote: I haven't looked any further but the daughter boards in the unit have 75 ohm resistors which I'm guessing determines the input/output impedance of the unit. If that's the case it should be easy to switch it to 50 ohms although it may not make any real difference. -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Hi Be careful with the BNC connectors on those switches. 75 ohm BNC's aren't the same as 50 ohm connectors. The inner contact is different enough that they don't always play well together. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: Thursday, February 21, 2013 3:57 PM To: time-nuts@febo.com Subject: [time-nuts] altinex switches I haven't looked any further but the daughter boards in the unit have 75 ohm resistors which I'm guessing determines the input/output impedance of the unit. If that's the case it should be easy to switch it to 50 ohms although it may not make any real difference. -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Good point Bob the 75 ohms are smaller in diameter. I use 75 ohm connectors. The 50 into a 75 hole spreads the jack. Regards Paul WB8TSL On Thu, Feb 21, 2013 at 4:16 PM, Bob Camp li...@rtty.us wrote: Hi Be careful with the BNC connectors on those switches. 75 ohm BNC's aren't the same as 50 ohm connectors. The inner contact is different enough that they don't always play well together. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: Thursday, February 21, 2013 3:57 PM To: time-nuts@febo.com Subject: [time-nuts] altinex switches I haven't looked any further but the daughter boards in the unit have 75 ohm resistors which I'm guessing determines the input/output impedance of the unit. If that's the case it should be easy to switch it to 50 ohms although it may not make any real difference. -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
I don't have the manual source offhand, but it will be in my msg archived. The RS232 does respond, and can also be used to control the unit I have. I got a nice note from the seller; apparently the time-nuts snatched these units up in less than a day...and it was the seller who put me on to the manual, a typical Google got me nothing. I'll be home next week, and can supply the manual URL then if you can't find it. Don Robert LaJeunesse I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Update: The manual is at: http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%20Run%20(HR)%20Series.pdf Just verified, and it's still there. Don Don Latham I don't have the manual source offhand, but it will be in my msg archived. The RS232 does respond, and can also be used to control the unit I have. I got a nice note from the seller; apparently the time-nuts snatched these units up in less than a day...and it was the seller who put me on to the manual, a typical Google got me nothing. I'll be home next week, and can supply the manual URL then if you can't find it. Don Robert LaJeunesse I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Don; I got one of those switchs;*very* nice product, great price. Wish I'd bought two! Do you have a reference for the mating connector for the RS232 by any chance? JimT Sent from *my* galaxy (Nexus). On Feb 21, 2013 4:13 PM, Don Latham d...@montana.com wrote: I don't have the manual source offhand, but it will be in my msg archived. The RS232 does respond, and can also be used to control the unit I have. I got a nice note from the seller; apparently the time-nuts snatched these units up in less than a day...and it was the seller who put me on to the manual, a typical Google got me nothing. I'll be home next week, and can supply the manual URL then if you can't find it. Don Robert LaJeunesse I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Hi Jim: I had to make up a little 3-pin to 9-pin adapter using loose pins. It just kinda hangs there... Don James Tucker Don; I got one of those switchs;*very* nice product, great price. Wish I'd bought two! Do you have a reference for the mating connector for the RS232 by any chance? JimT Sent from *my* galaxy (Nexus). On Feb 21, 2013 4:13 PM, Don Latham d...@montana.com wrote: I don't have the manual source offhand, but it will be in my msg archived. The RS232 does respond, and can also be used to control the unit I have. I got a nice note from the seller; apparently the time-nuts snatched these units up in less than a day...and it was the seller who put me on to the manual, a typical Google got me nothing. I'll be home next week, and can supply the manual URL then if you can't find it. Don Robert LaJeunesse I've been known to just stack a 150 Ohm 1% chip resistor on top of a 75 Ohm chip resistor to bring the result down to 50 Ohms. Beats having to 1) remove the old part, 2) clean up the pads, then 3) get the new one soldered down. Bob L. From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Thu, February 21, 2013 4:13:48 PM Subject: [time-nuts] altinex switches ... it should be easy to switch it to 50 ohms although it may not make any real difference. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
In general, no, they are not. The connector pins for modern 75ohm BNC's are exactly the same part as for modern 50 ohm BNC's. The BNC gets the higher impedance inside of the connection area by removing most of the inner dielectric. The real problem child, in general, is the female 75 ohm N connector, vs the male 50 ohm N connector. In this case, the connector has no dielectric in the mating area, so in order to keep the impedance constant, it has to have a smaller diameter center conductor on the 75 ohm variant. If you attempt to mate a 50 ohm male N connector with a 75 ohm female N connector, you will split out the female center socket pin. Legend has it that there were some variations of the 75 ohm BNC that don't work with 50 ohm variety I can't speak to whether or not that is true, only that in my 40 years in the business, I have never seen one where there was a problem. -Chuck Harris paul swed wrote: Good point Bob the 75 ohms are smaller in diameter. I use 75 ohm connectors. The 50 into a 75 hole spreads the jack. Regards Paul WB8TSL On Thu, Feb 21, 2013 at 4:16 PM, Bob Camp li...@rtty.us wrote: Hi Be careful with the BNC connectors on those switches. 75 ohm BNC's aren't the same as 50 ohm connectors. The inner contact is different enough that they don't always play well together. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Hi Chuck, some early 75R BNC designs did use a smaller diameter center contact. The 75R male can make intermittent contact when used with a worn or top of limit 50R female. The 75R female can be damaged for use with the small contact male if used with a 50R or large contact 75R male. The do exist, but are pretty rare. A lot got changed out as faulty. I've not seen one on any modern (last 20 years) equipment. Robert G8RPI. From: Chuck Harris cfhar...@erols.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, 22 February 2013, 6:15 Subject: Re: [time-nuts] altinex switches In general, no, they are not. The connector pins for modern 75ohm BNC's are exactly the same part as for modern 50 ohm BNC's. The BNC gets the higher impedance inside of the connection area by removing most of the inner dielectric. The real problem child, in general, is the female 75 ohm N connector, vs the male 50 ohm N connector. In this case, the connector has no dielectric in the mating area, so in order to keep the impedance constant, it has to have a smaller diameter center conductor on the 75 ohm variant. If you attempt to mate a 50 ohm male N connector with a 75 ohm female N connector, you will split out the female center socket pin. Legend has it that there were some variations of the 75 ohm BNC that don't work with 50 ohm variety I can't speak to whether or not that is true, only that in my 40 years in the business, I have never seen one where there was a problem. -Chuck Harris paul swed wrote: Good point Bob the 75 ohms are smaller in diameter. I use 75 ohm connectors. The 50 into a 75 hole spreads the jack. Regards Paul WB8TSL On Thu, Feb 21, 2013 at 4:16 PM, Bob Camp li...@rtty.us wrote: Hi Be careful with the BNC connectors on those switches. 75 ohm BNC's aren't the same as 50 ohm connectors. The inner contact is different enough that they don't always play well together. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Yes, this switch matrix seems intended for video signals, so 75 ohms is the expected standard. I doubt that would be much of a problem for 50 ohm timing signals. Some of us shall see soon. BNCs may be 75 ohm versions too, but probably not a big issue. On 2/11/2013 6:20 PM, J. L. Trantham wrote: Looks like 75 ohms if I understand the manual correctly. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Monday, February 11, 2013 8:00 PM To: time nuts Subject: [time-nuts] altinex switches I bought a couple of 180986059633 switches. The manual is at: http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%2 0Run%20(HR)%20Series.pdf You get 8 inputs switchable to 12 outputs IN ANY COMBO. meaning it can be a 12 output distribution amp. isolation amps all round, and either 200 or 300 MHz bandwidth. dc coupled, have a look. There are some left. Don ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] altinex switches
I bought a couple of 180986059633 switches. The manual is at: http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%20Run%20(HR)%20Series.pdf You get 8 inputs switchable to 12 outputs IN ANY COMBO. meaning it can be a 12 output distribution amp. isolation amps all round, and either 200 or 300 MHz bandwidth. dc coupled, have a look. There are some left. Don -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] altinex switches
Looks like 75 ohms if I understand the manual correctly. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Monday, February 11, 2013 8:00 PM To: time nuts Subject: [time-nuts] altinex switches I bought a couple of 180986059633 switches. The manual is at: http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%2 0Run%20(HR)%20Series.pdf You get 8 inputs switchable to 12 outputs IN ANY COMBO. meaning it can be a 12 output distribution amp. isolation amps all round, and either 200 or 300 MHz bandwidth. dc coupled, have a look. There are some left. Don -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] altinex switches
I just bought the last one at 11:30PM. -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
