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

[N2TK, Tony]

Frank,
Good info.
I have been using RG6 (Commscope F660BEF) for years for all my receive lines
and the feedlines for 80M 4-sq. The critters don't seem to ever bother this
slippery PE covering whether on the ground or buried. I use Belden
compression  F-connectors. Never had a failure with the connectors. About
once a year I use my XG-3 set to 10M to check loss to see if anything
changed dramatically. I do this will all of my coax.

Twice I laid out non-PE jacketed, non-flooded RG6. It didn't last 24 hours
before it was bitten in several places.   

73,
N2TK, Tony

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of
donovanf at starpower.net
Sent: Wednesday, January 10, 2018 2:58 PM
To: topband at contesting.com
Subject: Topband: Measured Loss in Copper Clad Steel RG-6 on 160 meters



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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