Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: Dressing RG6 Date: Sat, 18 May 2024 23:52:40 +1000 Organization: A noiseless patient Spider Lines: 35 Message-ID: References: <20240514b@crcomp.net> <66h74j1vfmbjvvl98jk1k017pimtinv2l5@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Sat, 18 May 2024 15:52:53 +0200 (CEST) Injection-Info: dont-email.me; posting-host="8c9b35e36545cc12300428201b91ce18"; logging-data="2957853"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19lQJ40ezMLoFJ2ucU0Z00XocMcZa+j2vU=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:gqTjdE5B7jEQB7eeHi/quF3qGZU= In-Reply-To: Content-Language: en-US Bytes: 2425 On 15/05/2024 8:08 am, Jeroen Belleman wrote: > On 5/14/24 23:46, Phil Hobbs wrote: >> John Larkin wrote: >>> On Tue, 14 May 2024 19:22:12 -0000 (UTC), "Don" wrote: >>> >>>> Phil Hobbs wrote: >>>>> Phil Hobbs wrote: >>>>>> Don Y wrote: > I've been putting coax inside copper tubes or braids to measure > and/or reduce the transfer impedance (leakage). I did that to > measure small signals in a particle accelerator, which typically > has kicker magnets and RF cavities with kA currents and kV > voltages nearby. > > A colleague developed a special low transfer impedance coax > cable for this sort of application. It had two screens with > intermediate magnetic shielding. It was unpleasant to work > with, because part of the magnetic shielding was a steel > spiral foil tape that was razor sharp. But it worked really > well. RG402 and RG405 semirigid coaxial cable has been around for ages. https://www.awcwire.com/rg-catalog/rg402-coax-cable With SMA soldered-on connectors it is good to 22GHz, and a solid copper tube as as a outer screen is pretty effective. Some people do have a passion for re-inventing the wheel. -- Bill Sloman, Sydney