ARRL

W1VT

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

Latest Topics

Topic Created Posts Views Last Activity
Antenna analyzer vs feedline type Sep 21st 2012, 14:37 1 1,182 on 21/9/12
USB to Serial Port problems--Prolific Drivers Aug 3rd 2012, 18:27 1 1,443 on 3/8/12
Italian Phishing emails! Dec 13th 2011, 14:20 1 1,263 on 13/12/11
John K0GMO needs help designing SS Amp Nov 17th 2011, 15:53 1 1,141 on 17/11/11
1 Farad Capacitor to Eliminate Headlight Flicker? Oct 19th 2011, 13:14 4 1,984 on 9/11/11
History of Relay Rack Dimensions? Oct 17th 2011, 12:58 2 1,359 on 25/10/11
Miswired Selsyn Oct 13th 2011, 17:51 1 1,206 on 13/10/11
Stealth Antenna wire Sep 12th 2011, 12:51 2 1,749 on 13/9/11
Designing a ham bench Aug 29th 2011, 12:38 2 1,820 on 29/8/11
Can't find recent Hint and Kink Aug 26th 2011, 13:01 1 1,747 on 26/8/11

Latest Posts

Topic Author Posted On
My first antenna questions ... tuulen 1 day, 3 hours ago
An OCFD isn't balanced. As a result, no matter how you orient the feedline, the feedline will affect the tuning. This is distinctly different from a center fed dipole--in which bringing down the feedline properly will minimize the tuning interaction.

Typically, one uses an OCFD to eliminate the need for open wire.
Open wire, while an effective way to minimize losses, can create the issue of wide impedance swings that are difficult for a tuner to match without excessive loss or voltage breakdown. So, while open wire can be made to work, you may need to experiment with different line lengths.

At present, nobody has found a good simple all band HF antenna--one that will operate from 80 through 10M with reasonable efficiency on all bands and no need for cut and try. Perhaps the closest is an inverted-L with an autotuner at the feedpoint. But, this antenna needs a radial system with good efficiency, and many hams would prefer to keep all the electronics in the shack.

Zack Lau W1VT
ARRL Senior Lab Engineer

Morse code pocket transceiver? KC9UNY 1 day, 3 hours ago
Dave Benson of Small Wonder Labs produced a kit for exactly that--it will even run off a 9V battery that also fits into the Altoids tin.

http://www.w0ch.net/rock-mite/rock-mite.htm

Dave has retired, but kits are still available from another source.

http://www.qrpme.com/

Zack Lau W1VT
ARRL Senior Lab Engineer
random wire antenna WD9DMM 2 days, 18 hours ago
http://www.w8ji.com/house_ground_layouts.htm

I'd suggest studying this page to choose the best way to bond your station ground to the service entrance. For lightning protection, you want a quick land easy path for lightning from your service entrance to the shack ground.

Zack W1VT
ARRL Senior Lab Engineer
psk31 with HRD(DM780) and IC7410 KR4YD 3 days, 3 hours ago

You are almost there.
You are missing the audio from the computer to the radio.

You may need to adjust a volume control on the computer.

Alternately, there may be a problem with the cable and/or interface between the computer and the radio.

It could also be that the default audio output device selected by the computer is wrong--you may need to choose the audio output device connected to the radio.

Zack Lau W1VT
ARRL Senior Lab Engineer

HF Beam Antenna Polarization WA9WVX 3 days, 5 hours ago

The advantage of horizontal polarization is that you get the benefit of ground gain--it is really hard to build a vertical beam with as much gain as a horizontal polarized beam. There certainly can be elevation angle advantages to vertical beams, but to some degree this is offset by the precise aiming capability afforded by the conventional Yagi/Tower. Being able to drop a noise source into a pattern null is a distinct advantage of a conventional beam.

Now that SDR receivers are becoming more common, it may make sense to connect an array of linear antennas to separate receivers and combine them with digital signal processing to optimize the polarization.

Zack Lau W1VT
ARRL Senior Lab Engineer

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