Return to Don's Home Page.

Photos of equipment, projects and items of general interest.

FT-857 mobile installation

The control head is mounted on a piece of 1/4" black acrylic which is attached to two 1-1/2" PVC pipe caps.  The pipe caps fit into the dual cup holder in the center console.  The speaker and microphone reside in the console storage area.

The antenna mount (prototype shown here) bolts to the front of the rear bumper channel and extends rearward under the rear bumper plastic appearance shroud so that just the ball mount is visible.  The final version is constructed from aluminum angle stock.

Printed circuit board etching tank

The etching tank is constructed from 3/16" acrylic. The fish tank heater heats the solution to 100+ degrees to speed up the etching process.  A fish tank air pump (not shown) injects air at the bottom and agitates the solution.

Acrylic can be tricky to cut with a power saw.  I tried a 10" 80-tooth carbide blade, but the acrylic got too hot.  A 60-tooth blade was better, but there was some chipping and heating.  A 40-tooth blade worked fine if I pulled the saw thru as fast as rapidly as it would cut.  The cut edge needs to be smooth in order for the solvent weld to work.  

Some completed construction projects

RF power reference.  See the article by W1GHZ on page 87 of the April 2007 QST.  The output is -10dBm +/-1dB.  The frequency is 50 MHz. Precision dc voltage reference.  5.000V +/- .01% (500 uV).  See the article on page 52 of the September 2007 Nuts & Volts.
Dual directional coupler, Elecraft CP1.  This unit is configured for a coupling of -30 dB and 250 watts. 150 watt balun, Elecraft BL1.  This unit is configured for 1:1, but can be rewired for 4:1.
Receiver test oscillator/S-meter calibrator, Elecraft XG2. RF output of  1 uV and 50 uV into 50 ohms on 3.5795 MHz, 7.040 MHz and 14.060 MHz. RF wideband noise generator, Elecraft N-gen.  Excess noise output of 35 dB from 100 kHz to 500 MHz.
Two tone test oscillator, Elecraft 2T-Gen.  Standard two-tone (700 and 1900 Hz) audio source for testing SSB transmitters for lineatity.  
DC voltage calibrator (side 1).  The LM399H has an initial accuracy of 6.95 Volts +/- 0.35V or 5%.  It has excellent (active) thermal control, but only moderate initial accuracy.  I believe it to be 6.853 V +/- 4 mV. DC voltage calibrator (side 2).  The two Maxim MAX876BCPA precision voltage references have an initial accuracy of .05% or 5mV either side of 10.000 Vdc.  These have no thermal control, but high initial accuracy.
DC voltage boost regulator.  Based on the article by N8XJK in the November 2004 issue of QST. RF matching transformer (2.25:1).  Matches 20 ohm antenna impedance to 50 ohm coax.  I use this with my mobile on 40M.

Projects in the planning/gathering stage

Rubidium oscillator frequency standard.  Idea from the article by K0IZ on page 49 of the Nov/Dec 2007 issue of QEX.  Step 1: find an oscillator.  This one came from China via Ebay.  Three position remote coax switch.  See the article by K5DVW on page 41 of the July 2006 QST.

PSK Meter.  From a link on page 50 of the December 2007 QST,

PIC-based TNC.  See the article by WB8WGA on page 16 of the Mar/Apr 2005 issue of QEX.  This project begins with a PIC Microcontroller prototype board from Olimex, shown here.

Hybrid cascode IF amplifier.  See the article by W7ZOI and WA7MLH on page 30 of the December 2007 QST.  


The Hy-Gain 18HT Hy-Tower vertical ready to tilt up, and in final position.  The full height is 51'.  The base insulators are attached to a 1/4" thick steel plate secured to the retaining wall footing with 5/8" x 8-1/2" stainless steel expansion anchors.

This antenna can't possibly work, being next to a retaining wall full of rebar and near the house with chicken wire in the stucco and 65' of aluminum gutter 5' away.  Fortunately, the antenna doesn't know that and it works just fine.

This is a Hustler 4-BTV that I keep around for portable operation.  Here it's installed in place of the umbrella in a metal patio table. The total height is about 24'.  Note the liberal use of concrete pavers to keep the table upright in spite of any wind or earthquake.  Three radials for each of four bands are on top of the ground.  Rube Goldberg lives!


Some deer grazing in the back yard and Mr. Coyote checking out the patio.

Return to Don's Home Page.