The mirror-image J-Pole is very easy to construct and requires only two T-Fittings plus a length of copper pipe.To visualize the antenna, one must only picture a 3 half-wavelength vertical and a 2 quarter-wavelength vertical positioned a few inches away from and centered on the the tall vertical. Construction of the mirror-image J-Pole is accomplished…
Category: Homebrew
Push pull 2m amplifier
Two 4CX1000A’s in grounded-screen push-pull – an amplifier that did not work. Describing this amplifier may seem a really silly thing to do, as it never worked well. However, someone else might learn from our mistakes, or even perhaps someone can tell us why it did not work. Background.A friend Paul G8WYI and I were…
PC-programming cable for Kenwood TH-G71A / TH-F6A
I wanted to make my own cable to program my Kenwood TH-G71A ham radio with a PC, but the owner’s manual simply did not show the pinout needed for the connector plugs. I searched the web but was not able to find this information but I did discover that several other radios used an RS-232-to-logic…
SWL home made antennas
Home-made antennas can greatly improve the performance of AM and FM radios, short-wave receivers, and scanners. If you are a talk-radio fan then experiment with the AM band antennas and you will be able to hear shows from all over the country with surprising clarity. Short-wave receivers are always coping with weak signals and they…
Kenwood TS-850S Mods
As posted to the CQ Contest e-mail reflector… Subject: TS-850 contest mods (long)Date: 4 Jun 1997From: David O Hachadorian, K6LLOrganization: cq-contest Mailing List [CQ-Contest] There was a huge number of requests for the TS-850 mods,so I’ll just post them here. Mod for External Keying, While Using the Internal Keyer –by N7EXFront Panel CW Sidetone Level…
The CobWebb Antenna
he G3TPW Cobwebb antenna covers five bands, 14 – 28 mhz, including the WARC bands. It is made by SRW Commuications Ltd (Steve Webb), Astrid House, Swinton, Malton, N. Yorkshire YO17 0SY (tel: 01653 697513). It is strongly made using fibre glass rods and comes pretuned, but is easily adjusted to one’s own frequency of…
Single Coax Feed to Multi-Band Copper Cactus Antenna
There are three connection possibilities to feed the multi-band copper cactus antenna with a single feedline or coax. However, it is imperative that you use the proper coax for the highest band of operation, RG58 just won’t cut it and even RG8 in lengths longer than 25 feet is marginal in 440 operation. For all…
The Optimized Wideband Antenna
Yagis for 20m – 10m by Nathan A. Miller NW3Z
The G5RV Antenna
THE G5RV ANTENNA The G5RV is a very popular antenna on the HF amateur band today. Despite it’s widespread use on the bands, there are some myths and misconceptions concerning the G5RV that seem to have a life of their own. Working with text from the ARRL “Antenna Compendium”, Volume 1, I would like to…
Single band copper pipe “J’ Antenna
N6JSX monoband J pole antenna dimensions