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Thursday, March 31, 2016

From Wayne and Garth in San Diego: EMRFD Joy of Oscillation Part 2



Oh great and mighty masters of the SolderSmoke:

We've continued on with this project and it has been a lot of fun.
Sure, there's
THE JOY OF OSCILLATION
but we've progressed to
THE JOY OF MODULATION (added a keyed buffer)
THE JOY OF AMPLIFICATION (added driver and PA, not threatening QRO, yet)






THE JOY OF RADIATION (perhaps my favorite)
THE JOY OF RECEPTION (picked up by RBN, yeah!)
last on the list is to experience
THE JOY OF COMMUNICATION

for that, we'll try out a number of different receivers.  Cheap SW
portableSoftrock Lite.  websdr.org.

Does one try to count all the joys?  :-)

Here's a few snaps:

0.jpg - RBN evidence
1.jpg - lashup on the lid of a tupperware container
This worked great for throwing the work in progress in a backback for
our build session meetups.
2.jpg - Fig 1.34 less output LPF.
3.jpg - The missing LPF.  THE JOY OF FILTRATION  (OK, that's taking it too far.)


4.jpg - Fig 1.35 amp with BD139 transistor.
5.jpg - "breadboard" and a front panel to hold the T/R switch.  Key
and cheap SW portable for RX.  Waiting for DX contest to end, so I
have a chance.  :-)

6.jpg - simple breadboard chassis

Our fun has certainly been cheap.  The parts cost, including PCB and 1
BNC jack, was about $13 in low quantity from Mouser (and Diz) for all
but the amp.  The amp portion was $4 in low quantity from Mouser (and
Diz), and most of that was the expensive heatsink.  The "chassis" was
just a piece of cheap 3/4" hardwood and lexan from home depot.  I
drilled and tapped the holes in the wood for the #4 screws.  (Seems to
hold quite nicely.  I thought I might have to harden the threads with
CA adhesive as is done sometimes with balsa.)

If there are any of those air variable caps left that you are meting
out to the worthy, well, like Wayne and Garth, "we are not worthy."
If you do have between 1 and 4 and find it in your heart, we'd be very
grateful.

Best regards,

Drew
kb9fko
San Diego

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