[Repeater-Builder] Cable velocity
I have been searching for the velocity factor for E86650 cable. This was the stamp on the cable. I think it is simular to RG-59 but want to make sure. I need to build a phasing harness and wanted to use this cable and of course the velocity factor is an important in determining the length. Thanks for any help Mike
RE: [Repeater-Builder] Cable velocity
Mike, The number E86650 is a listing reference for Underwriter's Laboratories. It is used to identify a class of wire and/or cable, not a specific part number. There may be dozens of cable products that share the same UL Listing number. Please advise the complete string of numbers that is stamped along the cable, and we may be able to identify what product you have. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of mike Sent: Monday, February 16, 2009 6:17 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Cable velocity I have been searching for the velocity factor for E86650 cable. This was the stamp on the cable. I think it is simular to RG-59 but want to make sure. I need to build a phasing harness and wanted to use this cable and of course the velocity factor is an important in determining the length. Thanks for any help Mike
RE: [Repeater-Builder] Cable velocity
If you have access to an MFJ antenna anal like the 259 series, in the manual it shows you how to determine the VF with it given a known length of cable to test. Don't know how accurate the measurement will be, but should get you close. Ralph W4XE -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of mike Sent: Monday, February 16, 2009 8:17 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Cable velocity I have been searching for the velocity factor for E86650 cable. This was the stamp on the cable. I think it is simular to RG-59 but want to make sure. I need to build a phasing harness and wanted to use this cable and of course the velocity factor is an important in determining the length. Thanks for any help Mike Yahoo! Groups Links
Re: [Repeater-Builder] Cable velocity
hi there -- Your making this all to hard -- if the coax is teflon then it is most likely .78 or .89 and if it isn't then it is .66. All of the velocity factors are in the ARRL antenna handbook. All you really need is information about the material in the coax and it will be easy to do. whether the center is foam, teflon, or plastic. take the velocity factor for it and built a 2 port harness. put 50 ohm resistors on the ports and measure the input SWR. If it is low, then measure the power into the harness and measure the power at one port. It shouldbe ~3db down. then your good to go. If it looks funny then meaure up and down a Meg and see if it gets any better. Assuming it does then your harness is long or short for the frequency you want to make it for. But most of the time you will be will within the necessary length if you get the correct factor. No matter who made it. GL -- Rick On Mon, Feb 16, 2009 at 7:27 PM, Ralph Hogan rhog...@comcast.net wrote: If you have access to an MFJ antenna anal like the 259 series, in the manual it shows you how to determine the VF with it given a known length of cable to test. Don't know how accurate the measurement will be, but should get you close. Ralph W4XE -Original Message- From: Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com] On Behalf Of mike Sent: Monday, February 16, 2009 8:17 AM To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Cable velocity I have been searching for the velocity factor for E86650 cable. This was the stamp on the cable. I think it is simular to RG-59 but want to make sure. I need to build a phasing harness and wanted to use this cable and of course the velocity factor is an important in determining the length. Thanks for any help Mike Yahoo! Groups Links