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I did ask Mts Goggle and got no (real) answer
Here is the label on the cable
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
Thanks
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Is there any way to tell if the dielectric is PE or foam?
73,
Joseph W6JHP
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On Sat, Jun 10, 2023 at 3:07?PM Anne Ranch <anneranch2442@...> wrote:
I did ask Mts Goggle and got no (real) answer
Here is the label on the cable
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High
Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
Thanks
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I am not sure I have another scrap cable I can take apart, This one has been given to me and I do not have same crimp connector to cut / restore it.
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On Sat, Jun 10, 2023 at 01:07 PM, Anne Ranch wrote:
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High
Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
It is foam dielectric with VF of 82% Roger
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How long is it?
Can you measure how long it is, then use the nano to see how long "Electrically" it is,
and there ya go you got it's VF.
Joe WB9SBD
.
A Contest 40 Years in The Making!
<>
MAIDENHEAD MAYHEM
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On 6/10/2023 3:41 PM, w6jhp wrote: Is there any way to tell if the dielectric is PE or foam?
73,
Joseph W6JHP
On Sat, Jun 10, 2023 at 3:07?PM Anne Ranch<anneranch2442@...> wrote:
I did ask Mts Goggle and got no (real) answer
Here is the label on the cable
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High
Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
Thanks
|
On 6/10/23 1:07 PM, Anne Ranch wrote: I did ask Mts Goggle and got no (real) answer
Here is the label on the cable
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
You might be able to figure it out from the 18 AWG (which is the diameter of the center conductor). The Z depends on the ratio of inner to outer diameter AND the epsilon of the dielectric. OTOH, who's to say that the center conductor really is 18 AWG. You might also be able to figure it out from the loss vs frequency. Or, perhaps, the mfr's website (which doesn't seem to go anywhere.. they may be out of business?) Since I saw some google references to it being used for satellite TV, I'm going to guess it's foam dielectric. Lower dielectric losses for higher frequencies. But testing a sample is the only way you'll know, if you can't get the mfr data sheet. If you have a sample and you cut it open, you'll know. foam looks different than solid.
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The wayback machine has it. The 39B2 link below the text leads to a PDF. 73 -Jim NU0C On Sat, 10 Jun 2023 13:07:27 -0700 "Anne Ranch" <anneranch2442@...> wrote: I did ask Mts Goggle and got no (real) answer
Here is the label on the cable
Eagle Aspen 39B2 RG-6 2.25 GHz Digital Coaxial Cable, 6FT, Black, High Performance 2.25 GHz CMX 18AWG 75¡ãC UL E227171
Please share if you know the velocity factor - VF .
Thanks
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On 6/10/23 7:34 PM, Jim Shorney wrote: The wayback machine has it.
The 39B2 link below the text leads to a PDF.
73
-Jim
NU0C foam, 82% VF
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Thanks, all reposes are greatly appreciated.
73 Vaclav AA7EJ
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Yes, well, the point was to have the OP go the last mile to get the information by following the archive link and maybe learn a thing or two in the process. This probably comes from having a mother who was a teacher. She had some clever ways of tricking me into learning things... 73 -Jim NU0C On Sat, 10 Jun 2023 20:31:21 -0700 "Jim Lux" <jimlux@...> wrote: foam, 82% VF
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Now something to remember,
The VF can be FAR from that spec.
I have seen Brand New cables that were different THAN THE SPECIFIED VALUE.
And as cables age, and it seems this stuff is OLD, that it changes sometimes a LOT as it gets older!
Joe WB9SBD
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On 6/11/2023 1:07 PM, Jim Shorney wrote: Yes, well, the point was to have the OP go the last mile to get the information by following the archive link and maybe learn a thing or two in the process. This probably comes from having a mother who was a teacher. She had some clever ways of tricking me into learning things...
73
-Jim
NU0C
On Sat, 10 Jun 2023 20:31:21 -0700
"Jim Lux"<jimlux@...> wrote:
foam, 82% VF
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On Sun, Jun 11, 2023 at 11:59 AM, Joe WB9SBD wrote:
Now something to remember,
The VF can be FAR from that spec.
I have seen Brand New cables that were different THAN THE SPECIFIED VALUE.
And as cables age, and it seems this stuff is OLD, that it changes
sometimes a LOT as it gets older!
Joe, Very good point about actual VF vs published VF. There are several ways to quickly get the actual VF of the cable using a NanoVNA but the OP ("Anne") doesn't like posts that go beyond specifically answering her question. Roger
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Ok, you said "there are several ways to determine the actual VF of a cable using a NanoVNA". WHY did you stop there? Dispense with the attitude and just TELL US what these methods are!!------ Original message------From: Roger Need via groups.ioDate: Sun, Jun 11, 2023 3:05 PMTo: [email protected];Cc: Subject:Re: [nanovna-users] Anybody happens to know VF of this cable ?On Sun, Jun 11, 2023 at 11:59 AM, Joe WB9SBD wrote:
Now something to remember,
The VF can be FAR from that spec.
I have seen Brand New cables that were different THAN THE SPECIFIED VALUE.
And as cables age, and it seems this stuff is OLD, that it changes
sometimes a LOT as it gets older!
Joe, Very good point about actual VF vs published VF. There are several ways to quickly get the actual VF of the cable using a NanoVNA but the OP ("Anne") doesn't like posts that go beyond specifically answering her question. Roger
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Very good point about actual VF vs published VF. There are several ways to quickly get the actual VF of the cable using a NanoVNA but the OP ("Anne") doesn't like posts that go beyond specifically answering her question.
OK, humor me and tel me TWO of several ways to ":get the actual VF of the cable using a NanoVNA"
PS
According to last test - my " digital ( other superlatives intentionally removed ) RG6" VF is .66 !
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On 6/11/23 4:23 PM, Richard Spohn wrote: Ok, you said "there are several ways to determine the actual VF of a cable using a NanoVNA". WHY did you stop there? Dispense with the attitude and just TELL US what these methods are!!- 1) use the NanoVNA to sweep and find out where 1/4 wavelength is (i.e. peak in S11 magnitude). Knowing the frequency where it's 1/4 wavelength, you can compare to free space wavelength. 2) Use the NanoVNA to measure the phase shift of the reflection at multiple frequencies, and then fit a straight line to the measurements, after unwrapping the phase. 3) Use the TDR function of the NanoVNA. All of these use a known length of cable, then you measure the electrical length of that length, and the ratio is the VF.
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Thank you, Jim. Much appreciated. -- Rich WB2GXM------ Original message------From: Jim LuxDate: Sun, Jun 11, 2023 8:33 PMTo: [email protected];Roger Need via groups.io;Cc: Subject:Re: [nanovna-users] Anybody happens to know VF of this cable ?On 6/11/23 4:23 PM, Richard Spohn wrote: Ok, you said "there are several ways to determine the actual VF of a cable using a NanoVNA". WHY did you stop there? Dispense with the attitude and just TELL US what these methods are!!- 1) use the NanoVNA to sweep and find out where 1/4 wavelength is (i.e. peak in S11 magnitude). Knowing the frequency where it's 1/4 wavelength, you can compare to free space wavelength. 2) Use the NanoVNA to measure the phase shift of the reflection at multiple frequencies, and then fit a straight line to the measurements, after unwrapping the phase. 3) Use the TDR function of the NanoVNA. All of these use a known length of cable, then you measure the electrical length of that length, and the ratio is the VF.
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Roger Need
Jim Shorney