Topband: Measured Loss in Copper Clad Steel RG-6 on 160 meters

[Richard (Rick) Karlquist]

AFAIK, the only reason they even make solid copper RG-6
at all is for applications that send DC over the coax to
operate such things as preamps.  DirecTV does that
a lot.

Rick N6RK

On 1/10/2018 11:58 AM, donovanf at starpower.net wrote:
> 
> 
> I measured the difference in loss (dB per 100 ft) between solid copper
> (SC) center conductor RG-6 vs. copper clad steel (CCS) Quad-Core RG-6 coaxial cable. The difference is insignificant on 160 meters until
> cable length exceeds 350 feet. You can see the affect of the steel
> core and its thin copper plating at 7 MHz and below in this table The cables were manufactured by two different companies, but the
> relative loss measurements should be valid.
> 
> A 1000 foot run of RG-6 with the more common CCS center conductor
> has 6 dB loss on 160 meters vs. 3 dB loss for the less common RG-6
> with an SC center conductor.  For most of us, the additional 3 dB
> loss in 1000 feet of CCS RG-6 will be insignificant. Solid   Copper  Cable length in
> Freq   Copper  Clad    feet for a 1 dB
> MHz    Loss    Loss    loss difference
> 
> 1.8    0.3     0.6          350
> 3.5    0.4     0.6          500
> 7.0    0.6     0.8          500
> 10     0.7     0.85         650
> 14     0.75    0.9          650
> 21     0.9     1.0         1000
> 28     1.0     1.1         1000
> 
> 73
> Frank
> W3LPL
> 
> 
> ----- Original Message -----
> 
> From: "Grant Saviers" <grants2 at pacbell.net>
> To: "Ryszard Tymkiewicz" <rtym at ippt.pan.pl>, topband at contesting.com
> Sent: Wednesday, January 10, 2018 4:23:34 PM
> Subject: Re: Topband: Supporting Ladder line
> 
> The shield is always the antenna element. The coax provides the signal
> return path when the direction is set with the far end as the feed point
> of the antenna. Since you likely will have a preamp for the large
> negative gain of a RBOG, a few db more from the coax won't matter except
> for a few db gain change when switching directions.
> 
> Here is some RG174 measured loss data (1db/100')
> http://www.dxing.info/equipment/rg_174_coax_bryant.dx
> 
> Much RG6 is Copper clad steel (CCS) so how much loss it has with copper
> that might be less than 1.8MHz skin depth is an interesting question.
> Any data out there? Solid Cu RG6 would be a safer bet. There are many
> RG6 variations and ones that are flooded might the best RBOG choice.
> 
> Grant KZ1W
> 
> 
> 
> On 1/10/2018 3:50 AM, Ryszard Tymkiewicz wrote:
>>
>> Hi Frank..I understand in the case of BOG we should use both
>> transformers T1 and T3 with
>> 4:1 impedance ratio... ?
>> I wonder if it is possible to use RG174 which unfortunately has quite
>> big attenuation even on 160m?
>>
>> 73 Rys
>> SP5EWY
>>
>>
>>> A reversible Beverage or BOG can be constructed out of a single run
>>> of RG-6, there's no need to form an open wire line out of two runs
>>> of RG-6,
>>>
>>>
>>> See ON4UN's Low Band DXing, Volume 5, page 7-88 and fig. 7-118
>>>
>>>
>>> 73
>>> Frank
>>> W3LPL
>>>
>>>
>>
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