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 1,241 on 21/9/12
USB to Serial Port problems--Prolific Drivers Aug 3rd 2012, 18:27 1 1,504 on 3/8/12
Italian Phishing emails! Dec 13th 2011, 14:20 1 1,304 on 13/12/11
John K0GMO needs help designing SS Amp Nov 17th 2011, 15:53 1 1,183 on 17/11/11
1 Farad Capacitor to Eliminate Headlight Flicker? Oct 19th 2011, 13:14 4 2,037 on 9/11/11
History of Relay Rack Dimensions? Oct 17th 2011, 12:58 2 1,399 on 25/10/11
Miswired Selsyn Oct 13th 2011, 17:51 1 1,244 on 13/10/11
Stealth Antenna wire Sep 12th 2011, 12:51 2 1,796 on 13/9/11
Designing a ham bench Aug 29th 2011, 12:38 2 1,872 on 29/8/11
Can't find recent Hint and Kink Aug 26th 2011, 13:01 1 1,803 on 26/8/11

Latest Posts

Topic Author Posted On
Yaseu FT 102 brakemanbobsmith 1 week ago

Malcolm NC4L has contact and bio information here
http://qrz.com/db/NC4L

Zack Lau W1VT
Upgrade MFJ 784? WA2SAY 1 week, 1 day ago
http://www.mfjenterprises.com/Product.php?productid=MFJ-784B
Firmware Upgrade
For MFJ-784 users, order MFJ-55, $29.95 Most software features of the new MFJ-784B.

A firmware upgrade is typically a programmable chip with the new software.

Zack Lau W1VT
ARRL Senior Lab Engineer
Long run 450 ohm ladder line KJ5GY 1 week, 4 days ago
Remote switching of ladder line is possible, but only if you run QRP, are very lucky, or carefully engineer your system to insure that the voltages are kept low at the switching points.

For many hams, the most practical approach may be to switch antennas using a 50 ohm coaxial switch located near the antennas.

1000' window line is likely to have 2 or 3 dB of loss on 20M, pehaps more in wet weather. You can cut than to less than a dB by using open wire instead of window line.

With this much line loss, you don't really want to run a high SWR, as the losses will become excessive, just like they do when you run moderate lengths of coax with a high SWR.

http://www.qth.com/ka9fox/open_wire.txt
Here is a summary on using long runs of open wire.

Zack Lau W1VT
ARRL Senior Lab Engineer
Restricted space multi band HF antenna recommendations Alfdude1 2 weeks, 1 day ago

http://www.arrl.org/limited-space-and-indoor-antennas
An All-Band Attic Antenna
Kai Siwiak, KE4PT, describes how to make an effective inverted L with an Icom AH-4 autotuner. QST October 2007 pp. 33-37.

Condo associates cannot entirely prohibit displays of the American Flag--now that the Freedom to Display the American Flag act of 2006 is the law of the land. A flagpole with an autotuner at the base can be a very effective antenna on many bands--a 20 ft flagpole works well on 40 through 10 meters,

Zack Lau W1VT
ARRL Senior Lab Engineer

Dipole or loop? KO0Y 3 weeks, 4 days ago
Another option may be to put up a wideband 80 meter antenna.

http://rudys.typepad.com/ant/files/antenna_broadband_dipole.pdf
Here is a clever open sleeve design by Rudy, N6LF--that actually covers frequencies above and below the 80M band!

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