Home |
Search |
Today's Posts |
#12
|
|||
|
|||
Hank, W5JFR wrote:
"Can someone please explain including the math, on how a ~500pf capacitor transforms 10 ohms to 50 ohms for 40 meters?" Go back to the books and look at L-networks. It`s in the book. In my 1970, 12th edition of the ARRL Antenna Book, an L-network example is given for matching a mobile whip to a 50-ohm line. It says on page 296: "For example, if it is desired to match a 50-ohm liner to a 20-ohm resistance, Xc will be about 46 ohms, and Xl about 25 ohms." Xl & Xc come from Fig. 15-12 which is used to match 50-ohm coax to whip antennas between 10 and 36 ohms. The Xc of 500pf at 7 MHz is 46 ohms. Xc = 1 / (6.28)(f)(C) Best regards, Richard Harrison, KB5WZI |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
"Homebrew FM tap" for the mobile ? | Antenna | |||
Opinions on Yaesu "ATAS" Mobile Antenna? (from experienced users, please) | Antenna | |||
Gamma match: Inherently inferior to balanced match systems? | Antenna | |||
Mobile Antennas | Antenna | |||
Need HF / Mobile Antenna Recommendation | Antenna |