[Boatanchors] Drake cable question (measured)?

[rbethman]

All,

How about Coleman Cable 92042 RG-6/U Quad Shield Swept to 30GHZ with a 
solid copper wire core?

I leave it up to Others to search for the "data" from them.

It is *indeed* what is used to run through all new homes here in 
Northern VA.

It also handles Security Systems.

One of the top installer/manager provided me with a 1000 ft roll.

Bob - N0DGN

On 6/11/2014 1:54 PM, Garey Barrell wrote:
> Ron -
>
> Au contraire!
>
> First of all, 'RG-6' doesn't mean anything.....  It's a holdover from 
> a military standard that DID specify characteristics, but is no longer 
> effective.
>
> There a several 'kinds' of RG-6, depending upon who sells it and what 
> it is intended for.
>
> The cheapest type, probably what you get from Radio Shack and 
> Cables-R-Us outfit, is a steel center conductor with a thin copper 
> plate, 60% shield coverage braid, and an aluminum foil outer shield.
>
> The stuff sold for burial has a gel injected dielectric to discourage 
> water ingress.
>
> The best stuff has a stranded copper center conductor, a gas injected 
> foam dielectric, and a full braid and aluminum foil outer shell.  This 
> is probably closest to the original 'real' RG-6, although I haven't 
> checked that.
>
> Yes, the copper clad steel center conductor version is reasonably low 
> loss 'up to 2200 MHz' as you say.   However, below ~7 MHz the loss 
> (specifically center conductor) increases due to skin effect.  The 7 
> MHz figure is for a specific copper plate thickness, but you can bet 
> the 'bargain' boys are making that copper plate a little over a micron 
> thick!  It only has to look like copper down to 50 MHz or whatever the 
> bottom end of the cable TV band is.
>
> Taking it on down to about 1 MHz (or 1 kHz?) used in your bridge, is 
> ALL in the steel, which 'may' account for your 'Lo-Q' (broad) dip!
>
> So...  The PreMixer signal for the stock 4-Line radios runs from 7.145 
> MHz up to 35.605 MHz.  So it's probably ok, but NOT optimum, depending 
> upon which version you happen to get.
>
> 73, Garey - K4OAH
> Glen Allen, VA
>
> Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
> and TR-4/C Service Supplement CDs
> <www.k4oah.com>
>
> Ron Bussiere via Boatanchors wrote:
>> Richard, thank you for the tip about the periods. I knew there had to 
>> be a way...
>>
>> One last thing on the cable, since this poor equine has been flogged 
>> enough.
>> I do have 2 Q Meters. A nice GR and a Heathkit. I didn't even think 
>> to measure the Q of the cable.....
>>
>> Lastly, what is strange about the RG-6 cable, is this stuff is 
>> supposed to be good to 2200 MHz, so it can't be too lossy... ha ha
>>
>> ron
>> N4UE