by Keith Kunde, K8KK
This document lists a few tools, documents and websites which are valuable in the design and construction of amateur RF power amplifiers. The list is small but it represents a good starting point for the amateur amplifier builder.
Item #9123, $12.95 plus S&H at www.arrl.org/catalog or toll-free 1-888-277-5239
This clever cardboard slide rule device enables you (with just a little practice) to accurately solve problems such as those listed below in a matter of seconds:
∑ frequency / wavelength conversion
∑ find inductance or capacitance which will resonate at a given frequency when either value is known
∑ find the resonant frequency given inductance and capacitance values
∑ coil turns per inch for a desired inductance given coil length and diameter
∑ coil length for a desired inductance given coil diameter and turns per inch
∑ close-wound coil length for a desired inductance given coil diameter and wire gauge
∑ turns per inch close-wound for a given wire gauge
∑ inductance of a coil given diameter, length and turns per inch
∑ inductance of a coil given diameter, length, and wire gauge
This easy-to-use tool should be considered absolutely indispensable to anyone who winds single-layer air core inductors. Its only downside is the priceówith shipping, it is around $20.00 (the essentially identical earlier model was only $2.00 postpaid!).
$99.95 kit / $129.95 assembled plus $6.00 shipping from Almost All Digital Electronics, www.aade.com/lcmeter.htm or telephone 1-253-351-9316 9AM to 9PM PST
This small, microprocessor-based inductance / capacitance meter has a digital readout and is generally accurate to within 1% of reading. It is autoranging and has .001 microhenry / .01 picofarad resolutionómuch finer resolution than most low-cost LCR meters on the market. This is exactly the ticket for determining tank component values, including the stray capacitances and inductances which heretofore could only be guessed at. The kit can be built in two to three hours and both the kit and assembled units have an unconditional, money-back guarantee.
You canít beat this thing with a stick! Get one!
Possibly the largest amateur radio, SWL and CB related website, The DXZone contains a veritable plethora of material of interest to radio amateurs. And, would you believe over ten thousand links? If youíre planning to build a linear amplifier or practically any other kind of amateur radio equipment you are bound to find useful information to help you at this site. †
Matt Erickson, KK5DR, has composed a small mountain of material on amplifier design and construction topics. Most of the material seems to be based on actual experiences by Matt and others and is quite useful. The topic on plate choke design (www.kk5dr.com/chokes.htm) should be checked out if you are planning to build an all-band HF amplifier and hate the smell of a burning plate choke.
This professional-looking site contains myriad subjects of interest to radio amateurs, including those with extended interests such as radio astronomy, etc. There are also a number of topical forums and several online receivers through which one may listen to stations on each receiver. The site has several subject areas which relate to linear RF power amplifiers.
>>>>> The End (for now) <<<<<
Keith Kunde, K8KK