[TowerTalk] Coax Losses on 160 and 75?

[Jim Brown]

Yes, these listings show the most significant specs.  Especially useful 
is the attenuation at 30 MHz. But what's lacking is data a 2 MHz for 
that RG6-like cable with the steel center and Al shield. That loss 
doesn't matter for RX antennas, but it CAN matter for TX antennas.

What can also matter is the shield resistance, which is the lower limit 
of the transfer impedance, which is a measure of shielding 
effectiveness.  Transfer impedance is the ratio of differential voltage 
inside the cable to common mode current on shield. The lower the 
transfer impedance, the better the shielding.

73, Jim K9YC

On Sun,8/7/2016 12:21 PM, Kevin wrote:
> So were all talking about the same stuff.
>
> Manufacturer's Part Number: /DXE-213U-1000/
> Coaxial Cable Type: RG-213/U
> Coaxial Cable Jacket Outside Diameter: 0.405 in.
> Coaxial Cable Jacket Material: PVC, Non-contaminating, Type II-A
> Center Conductor Gauge: 12.5 AWG
> Center Conductor Material: Bare copper
> Center Conductor Construction: 7 strand - 0.0296 in.
> Dielectric Material: Solid polyethylene
> Dielectric Outside Diameter: 0.285 in.
> Shield 1 Construction: Braided
> Shield 1 Material: Bare copper
> Shield 1 Percent Coverage: 96-97
> Loss Per 100 ft. at 30 MHz: 1.0 dB
> Velocity Factor Percentage: 66
> Coaxial Cable Length: 1,000 ft.
> Assembled: No
> UV-Resistant: Yes
> Direct Bury: Yes
>
>
> DXE Part Number: *DXE-11U*
> Coaxial Cable Type: RG-11/U
> Coaxial Cable Jacket Outside Diameter: 0.405 in.
> Coaxial Cable Jacket Material: PE, Type III
> Center Conductor Gauge: 14 AWG
> Center Conductor Material: Bare copper
> Center Conductor Construction: Solid
> Dielectric Material: Gas injected foam polyethylene
> Dielectric Outside Diameter: 0.280 in.
> Shield 1 Construction: Braided
> Shield 1 Material: Bare copper
> Shield 1 Percent Coverage: 97
> Loss Per 100 ft. at 30 MHz: 0.7 dB
> Velocity Factor Percentage: 84
> Assembled: No
> UV-Resistant: Yes
> Direct Bury: Yes
>
>
> //*C*oaxial Cable Type: RG-6/U
> Cable Connector End 1: Type F, male
> Cable Connector End 2: Type F, male
> Coaxial Cable Jacket Outside Diameter: 0.300 in.
> Coaxial Cable Jacket Material: PVC, Non-contaminating, Type II-A
> Center Conductor Gauge: 18 AWG
> Center Conductor Material: Copper-clad steel
> Center Conductor Construction: Solid
> Dielectric Material: Gas injected foam polyethylene
> Dielectric Outside Diameter: 0.178 in.
> Shield 1 Construction: Aluminum bonded polyester tape plus aluminum braid
> Shield 1 Material: Aluminum foil/aluminum braid
> Shield 1 Percent Coverage: 100
> Shield 2 Construction: Aluminum bonded mylar tape plus aluminum braid
> Shield 2 Material: Aluminum foil/aluminum braid
> Shield 2 Percent Coverage: 100
> Loss Per 100 ft. at 30 MHz: 1.1 dB
> Velocity Factor Percentage: 83
> UV-Resistant: Yes
> Direct Bury: Yes
>
> This what gets installed by Mediacom cable and the only one of the 
> four with a foil second shield. Comscope sells a gazillion miles of 
> this stiff. Because of the smaller diameter, .300 inches compared to 
> 4.05 I don't see how this could be mistaken for RG11U.
>
> DXE Part Number: *DXE-8U-1000*
> Coaxial Cable Type: RG-8/U
> Coaxial Cable Jacket Outside Diameter: 0.405 in.
> Coaxial Cable Jacket Material: PVC, Type I
> Center Conductor Gauge: 11 AWG
> Center Conductor Material: Bare copper
> Center Conductor Construction: 7 strands of 21 AWG
> Dielectric Material: Gas injected foam polyethylene
> Dielectric Outside Diameter: 0.285 in.
> Shield 1 Construction: Braided
> Shield 1 Material: Bare copper
> Shield 1 Percent Coverage: 95-97
> Loss Per 100 ft. at 30 MHz: 0.9 dB
> Velocity Factor Percentage: 81
> Coaxial Cable Length: 1,000 ft.
> Assembled: No
> UV-Resistant: Yes
> Direct Bury: No
>
> I have never used RG8U. I prefer RG213.