Now you see the set assembled and in operational condition. The Antenna - Ground terminal strip has been added as has a small antenna coupling variable cap on the front panel. Two antenna inputs are provided, one with 10pf in series for lighter coupling. The antenna variable is 5-25pf
I think its a done deal now. I didn't use an interstage transformer. What you see here is a 9 volt wall-wart using the primary side as an AF choke, typical RC coupling thereafter. The two shielded cables go to the volume control which is located between the first and second audio stage. This set has LOTS of volume which is handy for making other tweaks. One such tweak was using the secondary of the wart with a cap as an audio trap! That actually worked pretty well but it did suck down the volume a bit more than I wanted so I didn't keep it.
Fold Up Construction! The white wires are the audio output, yellow are the 6v AC filament, red/black is DC ~150 volts. Detector, btw, is running around 40-50 volts.
Had to change around the bandswitch and tickler location. I went with 4 bands. Its a bit tricky to get a common tickler to work on 4 bands but I was able to do so in this case. The tuning cap is only 50pf so it provides nice tuning without the need for a vernier drive. I had originally hoped to make it as high as 18 MHz with this set. As it turns out I have a bit too much stray capacitance (about 15pf) to allow for continuous coverage given that 50 pf tuning cap. I have one more bandswitch position and have a mind to add the 19-meter SWBC band, maybe if I'm lucky I can get 20 meter Amateur and 19 meter SWBC to squeeze into the same available slot.
With 4 bands a Tuning Chart sure comes in handy! On most of my project sets I like to shoot for the most coverage of Shortwave Broadcast bands as opposed to simply Amateur Band coverage. There's a few stations on the 90 meter broadcast band these days so I like to include it. Plus I can always count on CHU at 3330 kHz for the time signals at my location.
Almost finished. Need to rub out the finish on the cabinet and tighten it all down. It plays really well and its handy to not have to fuss with batteries.
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-Bill M, 10 November 2005
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