The motivation to have a useful all homebuilt transceiver led me to this project. In my case I decided to build it using mostly junkbox parts I have collected over the years - a combination of surplus stuff and components taken from old broken consumer items. With the exception of torroids purchased from partsandkits.com and crystals provided courtesy of Mac, AF4PS who had measured and matched them as part of a Flying Pigs Club group buy, all other parts are "what i had on hand." This often meant reasonable substitutions and in some cases circuit modifications. Perhaps this approach was inspired by reading many radio articles as a youth that encouraged scrounging components, and I had to do something with all this stuff I have been collecting!

I began the build by located a suitable enclosure, an aluminium box that previously had been used for some kind of test item. Its dimensions are 6 by 6 by 6 inches. This motivated using two boards, one mounted on the bottom containing the receiver and one mounted on top containing the transmitter.

The nature of being around components on hand and personal preferences meant this was not a build to print effort, but in most aspects my design follows the K8IQY design. I began building from the original schematics, and later incorporated some changes from the Plus version. Some key differences in my unit include:

A mechanical variable capacitor to tune the VFO Limiting my torroids to three styles - T50-2, T50-6 and FT37-43 Fixed coupling capacitors in the IF bandpass filter An LM386 for the final audio amplifier Use of two 2N2219 transistors for the transmit final Modification of the receive mute to use a N-channel FET Use of whatever NPN transistors I had in place of 2N2222 devices

The published circuit reflects the designer's original intent for all transistors to be 2N2222 based upon a building contest challenge. The plus version includes refinements that led to two FET devices used in the Plus version. My motivation was merely to use what components I have, but optimized to achieve good performance. I actually thought of even more changes such as using an IC IF amplifier, but the more I examined the design the more I appreciated it! Correspondance with Jim Kortge on the Yahoo Group led me to understanding the new RF amplifier and the use of LEDs in the design as voltage references.

ELSIE was used as a building tool to verify and select inductors and capacitors. This tool previously provided by the NJQRP club is invaluable to builders! A DVM was used along with a bench power supply to facilitate other measurements and testing as the unit was constructed. Final debugging of the receiver was done by connecting up an antenna tuned for 40 meters and finding my construction errors on the bench. A misoriented transistor in the high gain IF amp, and problems with the original RF amp led to low gain. These were remedied and the music of CW signals across the band was experienced! At this stage the rig was essentially breadboarded on the bench as it was only complete through the first audio stage, and the rest of the audio stage was borrowed from a previous project.

Above is a view from the top of the receiver board. The preselector is located in the upper right hand corner. As I used Elsie to measure the components, I was able to select capacitors to exact values and not need trimmers to realize this two pole filter. Just below is the RF amplifier - note the LED and the large encapsulated choke (with its horizontal stripes). A commercial mixer is mounted upside down on a pegboard, and then wired to the board. The VFO is at the bottom of the picture, the IF filter and cascode amp are in the middle of the board and fixed frequency oscillator (lone xtal and the "domino" capacitor) is at the left. The cascode amplifier was poorly positioned in the middle, so in my case i needed to shield the VFO to greatly reduce an overwhelming spurious signal around 7020 MHz.

Above is a side view of the receiver board. From left to right note the mixer, LNA and preselector filter. The latter used pairs of capacitors to achieve the values needed to avoid trimmers. In the background is a pegboard containing the LM386 audio amp not yet installed in the rig. The tuning variable capacitor is a high quality 30 pF unit.

Next I moved to building the transmitter section on a second board. To my dismay I did not have a second board fitting the dimensions, until i discovered the scrapped board from my earlier Ugly Weekender Receiver. As I had given up on this project, I removed the remaining parts from the board and used it to build this transmitter!

The fixed frequency transmit oscillator in the lower right feeds the balanced mixer to its left. Note the two yellow cased transistors that form the cascode amplifier. An on board trimmer is near the driver stage (the only actual 2N2222 transistor in my rig!) and the two 2N2219 transistors used in the final are located in the middle (bright purple heat sinks!). In the upper right corner is the output matching network.

Another difference in my approach is occasional use of "ugly construction techniques" along with manhattan techniques where the former made sense. For example, in the transmitter output network I decided it was more convenient to mount the inductors to the top of the capacitors instead of using manhattan pads. In many cases the manhattan construction leads to neater junctions particularly for small components. A wise builder can use both to advantage.

At this moment both boards are assembled. The transmitter has not yet been tested and I have not finalized details of the QSK circuit, but it will likely be similar to that employed in the SW-series because it fits the FETs i have on hand. I plan to run some low level tests on the transmitter, monitoring the output on a scope followed by tests of the complete transmitter. Then the whole unit will be integrated with QSK, and eventually RIT. I plan to post these advances.

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