On 19/08/2017 09:52, Ian Jackson wrote:
Spike writes
On 19/08/2017 09:32, Ian Jackson wrote:

Sheffield & District Wireless Society

///////////////////////////////////////////
Foundation Course Material in PDF Format

Posted: 18 Aug 2017 04:04 AM PDT

http://sheffieldwireless.org/2017/08...aterial-in-pdf
-format/

PDF File versions for the Foundation Course

Please may I offer one correction:

In 'Antennas & Feeders', the information about BNC connectors, you
are* warned "Take care not to mix incompatible 50 and 75 Ohm versions
which have* different inner pin sizes".

This is NOT totally correct. While the profile of the pins are
slightly* different (the 50 ohm usually has a somewhat stubbier
point), the* diameters are the same. The difference in characteristic
impedance is* achieved by the amount of PTFE dielectric.

As a result, you CAN physically mate 50 and 75 ohm BNC connectors
(both* sexes).

This is far too technical for a 'training scheme' that produces Fulls
who have to ask the question "USB/LSB? I'm confused!".

Don't worry - I can also confirm that both impedances of BNC connectors
are totally compatible with both USB and LSB.

I doubt knowing that would help the woodentop Full.


--
Spike