The following diagrams and tables show some simple 1:1 and 4:1 baluns for use between 1.8 and 30 MHz using twin transmission lines made from enamelled copper wire (ecw). The bifilar windings have been adjusted (spacing) to produce transmission lines with Zo of 50 or 75 ohms as required for best matching. These designs should…
Category: Articles
Here you can find articles I’ve cached, that are no more available in the net or are very rare to be found. Where possible credit will be given to authors.
Step-By-Step Construction of a 4:1 Current-Type Balun
Article by Charles Greene, W1CG My 4:1 current-type balun is wound on a FT-114-43 core. The FT-140-43 is a little easier to work with, and maybe the FT-140-77 would cover 160-10. This one is reasonably flat from 4.5 to 35 MHz but drops off a little at 3.5, 40-ohms with a 200 ohm resistor on…
HF Log Periodic Antenna
A plan for HF Log Periodic Antenna working 10-20 meters band by VA2PHI Pictures originally available at http://hb9tmw.free.fr/EuroNet/HTML/loghf.html
YOTA 2015 – trip to Florence
A visit to Florence by the Ham YOTA 2015 group
YOTA 2015 – II5YOTA
My recent visit to YOTA 2015
Modifying HP Server Power Supplies for Ham Radio Use
This article documents the modification of 2 typesof Hewlett Packard switching power supplies to enable their use as power sources for ham radio equipment. Obsolete server power modules can be bought from online dealers at very good prices due to the massive replacement of older network servers; typical prices for a unit are as low…
A Sleep Strategy for DX Contesting
A Sleep Strategy for DX Contesting This article originally appeared in the National Contest Journal. Why am I here? Listen to all these signals. Who are they? Wonder what they are doing? All this CW sure sounds nice. What should I do with this keyer paddle? Should I push this button? I can turn this…
QST November 2001
This evening at our local club, we were sorting old QST in our club library.
I just found this historical issue, dated November 2001.. with a hard-to-forget cover page.
Morgain Antenna 40/80
Here a plan for a Morgain Antenna for 40 and 80 meters band. This dualband antenna similar to a folded dipole permit to operate low bands by using a very limted space.
Philippines and CQ WW CW – 40 meters band usage
Received from Jojo DU1VHF, NTS Chairman and CFO for the Philippine Amateur Radio Association – please read and heed. “The much-awaited CQ WW CW Contest is nigh and everyone is chomping at the bit. However, here in the Philippines, our enthusiasm is a bit tempered by the recent events of a catastrophic typhoon which…