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January 5, 2025. More work on the Hybrid SSB Tube Final

With holidays being in the rear-view mirror, it is time to heat up the iron. That was on the schedule yesterday. 



12DQ7 Driver Circuit

Above is the 12DQ7 Driver tube and to the right of that the 40M Band pass Filter. A few more resistors to install and this stage will be complete ready to test.

The parts layout was done on graph paper as a first step and then the CNC Island Squares were cut using the coordinates from the graph paper. This process aids in making a somewhat compact layout, facilitates keeping the "ins from the outs" yet provides some breathing room for the inevitable changes and improvements. I believe this to be an alternative approach versus gluing down a bunch of Manhattan pads and doing "ugly".

Once the 12DQ7 Driver stage is complete the next task (before testing) is to wire up on both ends the power/control cable that goes to the main board. This cable is about a foot long and is hardwired to the Tube Final but on the other end to the main board has a 9-pin miniature plug and socket. Once this cable install is done then I can test the 12DQ7 Driver stage. The plug and socket interconnect facilitates removing the assembly, so I can finish off the 12GE5 Final Amp stage. How cool is that? The separation cable also enables the installation of physical shielding should RF feedback becomes an issue. You have to think of everything.

Tomorrow is January 6th, which marks a day of insurrection in the US.  One law maker suggested making it a national holiday. What have we become and how do we fix this? Part of the fix is time like 1462 days.

Light up the iron and make some smoke.

73's
Pete N6QW

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