[TowerTalk] Marine Grade Coax -- NOT!

[Grant Saviers]

Jim,

I think you got a rip off version of the Ancor brand, your Ankor is 
Chinese is my guess.  I've used up a 250' spool of what is marked RG8 
and last measured the 165' length remaining was right on spec for loss 
at 30MHz and even then it was 15 years old.

I've used a lot of Ancor products over the years and found them right on 
spec, tinned conductors from 10 to 18ga, and the coax is exactly as 
specified tinned center Cu and tinned shield and sturdy jacket.

And yes, RF stuff at Marine suppliers will empty your wallet vs 
communications industry suppliers.

Grant KZ1W



On 9/24/2017 13:58 PM, Jim Brown wrote:
> Several years ago, I did a friend a favor by providing guidance about 
> suppressing RFI to the HF installation on her sailboat. As you might 
> guess, I gave her a bunch of ferrite cores. In appreciation, she gave 
> me a short length (turned out to be 28 ft) of a so-called "Marine 
> Grade" coax with an Ankor brand. It had laid on a shelf outside the 
> shack until I picked it up a few days ago, put a connector on one end, 
> hooked it up to my VNWA, did a TDR sweep, made 5 MHz to 100 MHz 
> shorted and open impedance sweeps, and fed them to ZPlots to compute 
> Zo, VF, and attenuation.
>
> Results were unimpressive, but unsurprising given a physical 
> examination of the cable. It's labeled RG213, has a flimsy outer 
> jacket that is easily nicked, a tinned copper braid that's also easily 
> nicked, and what appears to be a stranded copper-clad steel center! 
> Loss was 0.77dB/100 ft at 10 MHz, VF was 0.669. The outer jacket came 
> to me nicked in one place (a slice about 0.5 in long), and there was 
> obvious staining from corrosion of shield that lay beneath it.
>
> The Ankor website describes their RG213 as having a "premium tinned 
> copper center conductor as well as a tinned copper outer braid for 
> corrosion resistance and easy soldering. It features signal loss 
> ratios of up to 50 percent less than other coaxial cables. 96 percent 
> braid provides best signal strength and least interference with UV 
> inhibited white jacket for longest life." The website contains no specs.
>
> In fact, loss is significantly greater than ordinary good quality RG8 
> and RG213 from companies like Belden, Times, and Davis RF, and 
> physical properties are significantly worse. Amazon sells a 100 ft 
> length for $95. And they'll sell you Shakespeare-branded gold 
> PL259-knockoffs for $12.87 EACH!  A gold plated barrel (also a 
> knock-off) will set you back $11.74. Compare with great coax like 
> Buryflex with AWG 9.5 stranded copper shield, foil plus tinned copper 
> braid shield, and really nice UV-resistant PE jacket. 100 ft costs you 
> $0.89/ft.
>
> This marine stuff is on the level of the ultra-expensive but useless 
> stuff sold to high-futility folks!
>
> 73, Jim K9YC
>
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