While removing the old capacitors that will be replaced, I found a funky modification made to the underside of the chassis. Someone had soldered 20 ohms of high wattage resistors across a new tie strip that was added. It is a poor quality change, just as I found quite a few solder joints which were amateurish at best.
|Resistors inserted in series with magic eye tube filament|
Until I replace the capacitors and power this up, I really don't know if the 6E5 tube is working. If it works well, I will dress up and leave this little mod in place but if I need a new tube, I will just go back to a 1629 and drop the extraneous resistors. The wiring of the socket for the 1629 is different from that of the 6E5, thus I have to rewire that also if I switch back.
HEATHKIT HW-100 SSB TRANSCEIVER RESTORATION AND MODIFICATION
I am working on the layout for the external box that will hold my direct digital synthesizer that replaces the VFO inside the HW-100. I need to lock in the orientation I want and the placement of the LCD, rotary encoder and three pushbuttons. Further, I need to decide on the power supply and RF output connector types and placement.
|Aluminum box for DDS VFO|
|DDS and LCD to mount inside|
|Rotary encoder and RF output jack|
|Buttons and knob to complete the front panel|
Meanwhile, the microphone arrived - a historically accurate choice, an Astatic D-1604, and I hooked it up to the transceiver. Now, I could perform the transmitter alignment steps from the Heathkit manual. That is, I could if I hadn't disassembled the DDS VFO. First, I have to complete the construction of the DDS in its box.
I punched the holes for the three pushbuttons and mounted them. The hole for the LCD is cut out, although a bit uneven because of the way I had to make the rectangular slot. My hole for the rotary encoder is too small, thus I have to step up one size and punch again.
I will need to carefully measure, mark and drill the small holes for the mounting hardware that will hold the LCD in place behind the panel. At the same time, I should create the holes on the bottom to mount the main DDS PCB.
I still have not finalized the RF output and power input jacks, thus can't punch the holes in the rear yet. I have a number of heathkit style rubber feet and will place four of them on the bottom of this enclosure to allow it to stand a bit above the HW-100 cabinet top.
I chose to run over to Anchor Electronics to pick up the RF and power jacks, which would let me complete the project tonight. Sadly when I mounted the LCD panel, the backlight broke from flexing of the board. It works but need external light.
After dinner, I had both boards mounted and was wiring up the controls. I finished at night but wasn't ready to test it out until the morning.