Those attending today were Richard W1WUH, Fred KJ6OOV, Eric KK6IZY,Warren
\nNR0V, Glen KG0T and Ron W6WO. This is truly a group with such a wide range
\nof knowledge that two hours of concentrated discussion could only scratch
\nthe surface of any one topic. Fred showed a professional VHF folded dipole
\nwhich he rescued from a dump. It was part of an array of dipoles that
\nincorporated impedance matching achieved with sections of coax within the
\ntubing. As many know Ron can become unBalUnced when coax is involved and
\nmust resist beating his chest. Forgive but how would you answer this.
\nGiven two sections of cable, one twin lead and the other coax. Which
\ncould be described as a balanced transmission line? Answer at the end of
\nthis note.<\/p>\n
The conversation today had much to say about connectivity. Ron bemoaned
\nthe need to have special cables and connectors, for example the 8pin DIN
\nconnector on a typical radio and the USB connector now standard on PCs.
\nOne day we woke up and parallel ports were gone followed by serial ports
\nwhat next, fiber Bluetooth ?. Glen made a kind offer to explain and
\nassist. Eric showed a diabolical mix of connectors associated with power
\nsupply and other subsystems in his PC. The tour of his Lenovo P51 thinkpad
\nlaptop was quite simply astounding.<\/p>\n
Both Eric and Warren described some of the precautions they take to
\nsafeguard their data. Warren mentioned his recent work developing
\nsoftware to take care of anomalies affecting High Performance SDR
\nbehavior due to the buffering and reading of data packets. Warren is a
\ntrue pioneer, builder and problem solver.<\/p>\n
Now to the question. The answer is both as they are inherently balanced.
\nThe twin lead is obvious but ideal coax will carry exactly differential E
\nand H fields internally ie balanced conditions. Consider a 50 Ohm coax
\nterminated in two 25 Ohm non radiating resistors in series with their
\njunction connected to some reference point. No common mode current will
\nflow back to the source via the reference point. It is radiation from an
\nunbalanced system or antenna (most are to one degree or another) and the
\nshielding property of the outer conductor that causes common-mode feedline
\ncurrent and radiation. An even more engaging question is, if it does why
\nshould we care ?<\/p>\n
Our next CAKE date is Dec 9<\/span><\/span> which is the date for our Club dinner at 6 PM<\/span><\/span> 73 Vibrate effectively CAKE Notes for Nov 25, 2017 Those attending today were Richard W1WUH, Fred KJ6OOV, Eric KK6IZY,Warren NR0V, Glen KG0T and Ron W6WO. This is truly a group with such a wide range of knowledge that two hours of concentrated discussion could …<\/p>\n
\nstay tuned for details<\/p>\n
\nRon W6WO<\/p>\n","protected":false},"excerpt":{"rendered":"