Tektronix used nichrome coax for many of its passive probes, the almost
perfect lossy cable! Pretty small coax though!! I would believe other probe
mfrs used it too.
Don W7WLL
-----Original Message-----
From: Mike Fahmie via TowerTalk
Sent: Saturday, November 29, 2014 5:07 PM
To: Towertalk Reflector
Subject: Re: [TowerTalk] Coax loss. Has anybody measured it ?
How about maybe in a underground nuclear test bore hole, it would deliver
the signal before the coax melted entirely (?).-Mike-
From: Jim Lux <jimlux@earthlink.net>
To: towertalk@contesting.com
Sent: Saturday, November 29, 2014 4:37 PM
Subject: Re: [TowerTalk] Coax loss. Has anybody measured it ?
On 11/29/14, 10:36 AM, David Robbins wrote:
You want some lossy coax? I have a couple old rolls where both the center
conductor and shield are nichrome. VERY lossy stuff!
What would they use nichrome coax for? Some sort of test jig for heating?
For use in a refractory or corrosive environment? I think I've seen
hastelloy or something other superalloy.
I've seen stainless steel coax for cryogenic applications (very low
thermal conductivity going in and out of a dewar), but it had a thin
silver plating. For microwave frequencies, the plating was thicker than
skin depth.
I've also seen delay line coax, where the center conductor is a tight
helix: the inductance/unit length is high so the propagation speed is
slow (and the Z is high, too). That stuff was quite lossy, although not
in a "dB/wavelength" sense.
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