Baluns - What They Do and How They Do It
- Details
- Written by: G Wolfe - KI0KK
An Article by Roy W. Lewallen, W7EL
A classic article on how Baluns work and the practical aspects of using them.
Web Link: W7EL Balun Article
PDF Link: Local site PDF
How To Bias An Op-Amp
- Details
- Written by: G Wolfe - KI0KK
An MIT OpenCourseWare article provides details on how to bias an Op-Amp.
Web Link: Biasing An Op-Amp
PDF Link: Op-Amp PDF
Inverted L Antenna
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- Written by: L Hall - KD0RIU
An Inverted-L antenna might be one to consider for low bands during this part of the sunspot cycle.
The attached file is available on the internet and describes how to make an Inverted-L antenna using RG-58 coax to make the traps. The Inverted-L antenna only requires a single trap per band vs two for inverted vee antennas. Plus some installations are more difficult when you have to fed to middle of a dipole.
The basic design process can be used for any combinations of bands but two or three bands will be easier than a larger number. You can make it with any reasonable size plastice pile, #14 wire, coax, silicone sealer and tape/heat shrink.
The article discussions what kind of ground system is needed/used with this antenna. Ground rod and ground radials would be the expected ground system but as noted if the ground radials are buried a few inches in the ground then they can be shorter than 1/4 wavelength with still provide acceptable performance.
Hope this is helpful to anyone wanting to get on the low bands for the next few years.
73
Larry Hall
KD0RIU
Arduino RF Signal Generator
- Details
- Written by: G Wolfe - KI0KK
Source: QEX (Elwood Downey, WB0OEW)
The September/October 2018 QEX contains an article on building a Arduino based RF signal generator. The device has a range of 500 KHz to 40 MHz and is stabilizwed with a GPS receiver. The article title is "Simple and Accurate Variable Frequency RF Signal Generator".
Nano-Spot WIFI Digital Ham Hotspot
- Details
- Written by: G Wolfe - KI0KK
New DMR / DSTAR / Fusion / P25 Nano-Spot WIFI Digital Ham HotspotBy - Micro Node International
NANO-SPOT is a completely self-contained digital hotspot supporting DMR, Dstar, P25 and System Fusion communications.
There is also a Youtube video on the device and it's setup.