10 Element Quad-Yagi (Quagi) for 900 MHz Band
Elements 1-7 are spaced 3 inches (7.6 cm) apart on the boom. There is 6 inches (15.2 cm) between elements 7 and 8. There is 2 3/4 inches (7 cm) between elements 8 &...
Monthly Archive: August 2018
Improved audio quality for the Heathkit TX-1 Apache
Actually, much of the so-called “scratchiness” which Apaches are famous for is simply due to misadjustment of the clipper circuits. However if you’d like a little more range in the frequency response, particularly low...
Bench AF Amplifier. Schematic Diagram.
The circuit… This circuit consists of just a few discrete components and one common IC amplifier – the LM380N. It’s simple, cheap, quick to build and works well. I built mine in a steel,...
A.C Electricity …and why I hate it!
When I say A.C electricity I mean the kind of high-voltage stuff we have in our homes. So before anybody says: “Well, aren’t radio waves a form of A.C?”, let me explain what I...
Multiband Receiver Sony ICF SW100 (Review)
This was a single-chip radio manufactured in the 1990s and early 2000s. It was marketed as a “world-band receiver”. It covers 150kHz to 30MHz and FM from 76MHz to 108MHz. The set decodes stereo...
Lightning and other mishaps
About a year or so ago, I was presented with a Philips transistor radio that according to the owner had been struck by lightning. Fortunately, the lightning strike must have been quite some distance...
Few words about National Radio Corporation
National was founded in 1914 as “The National Toy Company”, but by 1916 had broadened their range and renamed themselves as the “National Company Inc”. By the 1920s, they made a start into radio...
5 element quad for 2m band
Boom Length – 1651 mm Distance between: Between Distance, mm R – V 432 V – D1 330 D1 – D2 406 D2 – D3 483 Dimenson of elements: Side, mm Diagonal, mm Perimeter,...
QRP Dummy Antenna
I needed a small dummy antenna for testing my Elecraft K2. It was to be small and capable of being used into the VHF range. It had to have a BNC connector, and it...
The Twelfth Wave Matching Network
Although the mismatch between 50 Ohm and 75 Ohm systems are usually acceptable, it’s easy to obtain a near perfect match using a pair of twelfth wave lines. The nice part is you only...
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