Update on the High-School Direct Conversion Receiver Project: Board #4 Completed

One of the receivers. (l to r) AF, PTO, Mixer, BP filter

The students continue to make great progress on their direct conversion receivers.  Yesterday they were enthusiastically sitting down to workbenches, building Manhattan-style circuits, working directly from schematic diagrams.  It was really impressive.  They are building receivers. 

This week we had two sessions of about two hours each. We introduced the final board:  the audio amplifier.  Many of the students began work on this amplifier; others were catching up with work on boards presented earlier. 

The AF amp is their most challenging board:  It used 14 Manhattan pads and about 26 components.  We warned the students that amplifiers often aspire to be oscillators.  We told them to pay attention to layout, and to keep their leads short.  

One of my builds, and a Manhattan board pattern

At first, the students just built the first stage on the AF amp board. They tested this, then moved on to build the other two stages.   

By the end of Friday, two groups had completed the build of the AF amplifier board.  

We think there are about 13 receivers in production.  Some are near completion, others will need more work.  

On Thursday of next week those teams that have completed all four boards will put the circuits together and will test the entire system.  They will then add all needed front and back panels and socketry. 

We really want the students to complete as many of these receivers as possible.  Exam season and the end of the school year is approaching, so we have to get this done.  We will remind students that they don't want to that person who ALMOST finished a project!  We will urge them to GET IT DONE!   They can tweak it and mod it later.  This kind of tweaking and modification is part of the homebrew experience. 

We have been presenting awards to the students who are first to complete each stage:  The winners of the PTO board competition got a copy of SolderSmoke:  Global Adventures in Wireless Electronics.   Those who won the mixer competition got a W1REX Hamfest Buddy transmitter.  Thanks Rex!  And this week we presented an award to the students who were the first to complete their bandpass filter.  You've heard of the Tony, the Emmy and the Grammy?  Well, we presented "The Torry"  (from Toroidal).  The trophy was made from a toroidal winding tool made in Alaska by KL7FLR.  I explained to the students who had made it.  Thanks Paul! 

"The Torry"