[TowerTalk] weird coax

[Jim Lux]

On 12/10/11 7:46 AM, George Dubovsky wrote:
> Dunno, Dave, but I ran into something that sounds like that, about 30 years
> ago. The center conductor was something with measurably higher resistance
> than copper. I was told it was for making delay lines - useless for normal
> transmission line use.
>

The delay line stuff actually has a spiraled inner conductor (to 
increase the series L  (so that sqrt(L*C) is big), so a foot of coax has 
a lot more than a foot of (very small diameter) copper wire in it.

Since Z is sqrt (L/C) that also makes the impedance of the line high (I 
seem to recall around 1000 ohms)



> 73,
>
> geo - n4ua
>
> On Sat, Dec 10, 2011 at 10:13 AM, K1TTT<K1TTT at arrl.net>  wrote:
>
>> Grabbed some stuff they were going to throw away at work. no type marked on
>> it, only mfg info is "IT&T Federal Cable REC".  Looks almost new so thought
>> it might be good for something.  About the size of RG-6, but has thinner
>> center conductor, partial air dielectric, and very tight single layer braid
>> shield.  Odd part is that it has very high loss. maybe some kind of early
>> version of RG-126 or RG-301??  Any idea what this might be used for?

How did you measure the loss?  If it had a real high Z would that look 
like high loss?