Friday, January 1, 2016

One Watter: Phase Four through Phase Eight..

I didn't necessarily blast through the middle and ending phases but I did not document them as thoroughly as I should have. (In fact, I did not document the first phases that completely either. Pretty much a bunch of pictures with comments. But then again, I did so for the following reasons:

(1) I was lazy.
(2) I was absorbed in the building process.
(3) I was learning as much as I could.
(4) Chuck Adams did a better job than I could ever do.

So here's up to Phase Eight -- the driver stage. Everything up through this stage checked out fine and I was set to sail through the last stage (the final and the output bandpass filter) when I hit a bump which I will describe in a final post. However, the bottom line was that the rig ultimately passed with flying colors and is waiting for a home.

So here's some pictures and comments for the last phases.

The T5 transformer on the 15m 1-Watter is wound on a BN-43-2402 binocular core and is actually pretty simple once one realizes that a complete turn is one pass through BOTH holes. (It is, therefore, possible to do a half turn.) If you follow the instructions re wire size and wind the 8-turn secondary first, it's a piece of cake.

T5 wound and ready to go. This one looks like the alien in Independence Day, don't it?

T5 in situ..

..ibidem.

Left is T4 (VXO circuit) and L1 or L2 (output bandpass filter). (They are identical).

Here is T4 along with L5 in the VXO circuit. Note L5 (left) was wound with 40 turns.

The primary windings of T2 and T3. They require a 1-turn loop for this secondaries.

The whole board just before adding the driver and final stages.

The completed driver stage with T1 in place. Note that this is an FT-37-61, the dull grey toroid.

Whole board up through the driver stage.


The tricky part is adjusting the pre-driver bandpass filter -- between C23 and C24 but that is only marginally nigglesome to adjust. For the transformers in this stage. Diz recommends an alternative of stripping the entire length of the one-turn secondary for each of these transformers but I opted to use semi-long pieces of bare clipped component leads I had lying around. They were more riggid and saves me the work of tinning, etc.

Also, be sure you get T1 and L4 wound on the correct core. T1 is wound on the FT37-61 core which is dull grey. L4 is wound on an FT37-43 which is blacker and more shiny.

..on to my final adventure!

-72-

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