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W1VT

Joined: Sat, Apr 4th 1998, 00:00 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
QST Downloads Feb 19th 2016, 16:34 1 703 on 19/2/16
March 2016 QST Compact Multiband Dipole Feb 19th 2016, 15:23 1 607 on 19/2/16
Antenna analyzer vs feedline type Sep 21st 2012, 14:37 1 2,531 on 21/9/12
USB to Serial Port problems--Prolific Drivers Aug 3rd 2012, 18:27 2 3,058 on 26/12/15
Italian Phishing emails! Dec 13th 2011, 14:20 1 2,202 on 13/12/11
John K0GMO needs help designing SS Amp Nov 17th 2011, 15:53 1 2,031 on 17/11/11
1 Farad Capacitor to Eliminate Headlight Flicker? Oct 19th 2011, 13:14 4 3,563 on 9/11/11
History of Relay Rack Dimensions? Oct 17th 2011, 12:58 2 2,311 on 25/10/11
Miswired Selsyn Oct 13th 2011, 17:51 1 2,199 on 13/10/11
Stealth Antenna wire Sep 12th 2011, 12:51 2 2,842 on 13/9/11

Latest Posts

Topic Author Posted On
G5RV Antenna Question N5ERV 1 hour, 14 minutes ago
The G5RV has a moderate SWR of around 4:1 on 40M. With a properly tuned antenna tuner, reasonable efficiency can be obtained when fed with the normal ladder line/coax configuration.

http://www.w5dxp.com/G5RV/G5RV.HTM
Cecil shows how the window line modifies the feedpoint impedance on a Smith Chart.

http://www.karinya.net/g3txq/g5rv/
This page by G3TXQ suggests 2 dB of coaxial line loss on 40M. He also suggests the shorter ZS6BKW as a similar antenna that will cover all of 40M without a tuner.

Zack W1VT
ARRL Senior Lab Engineer

End Fed QRP Antenna kd9equ 3 days, 20 hours ago
It sounds like you have some sort of basic wiring problem. I'd suggest testing the coax, perhaps with a dummy load and separate antenna.

It can be very frustrating to figure out what is wrong. Sometimes the best thing to do is to set it aside and build something else, then get back to it later. Having someone check your work isn't always practical.

Zack W1VT
ARRL Senior Lab Engineer
TLW W0QQG 4 days ago
The downloaded TLW3 needs to be installed on computer that already has an older version of TLW installed.
450Ω vs 600Ω ladder linr to feed loop antenna using 4:1 Balun WA2FTV 4 days, 4 hours ago
No, the only advantage of using 450 ohm ladder line is lower losses. Typically there aren't any matching issues using 50 coax. Nor is there a particular common mode advantage, as loop itself often provides a degree of common mode rejection.

In order to provide a lot of common mode rejection, two cores are typically required. Many designs use only one to cut costs, sacrificing common mode performance.

Zack Lau W1VT
ARRL Senior Lab Engineer
QSL Cards still used? KD2LZS 3 weeks ago
The site QRZ.com has station profiles that allow stations to indicate whether or not they QSL via mail. To avoid wasting time and effort, my profile includes a Clublog lookup so you can see if you are in the log.

Zack W1VT
ARRL Senior Lab Engineer

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