[ARC5] Stinson’s DC to DC converters

[David Stinson]

-----Original Message-----
From: Tom Bridgers
Subject: [ARC5] Stinson’s DC to DC converters

This is exciting stuff.  Hats off to David Stinson who puts new meaning into keeping those filaments lit.
73’s
Tom. KE4RHH 
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Tom, you and so many are ever kinder to me than I deserve.  This "design" if one can all it that, is still in the "tweaking" stage.  I just now discovered that, if I remove the antenna, I can hear some noise around 40 and above.  With the antenna on, I haven't found any around 30, 40 or 80 meters, it seems to be under the receiver's noise floor.

I tried making this one with fewer ferrites than the last one, thinking I may have "overdone" that one.  Here's the photos:
https://photos.app.goo.gl/uAXN9Jfw9oCXuQC03
https://photos.app.goo.gl/4LmZIDuMJVbIszXt2

I probably should have tuned everywhere before writing- not just around 80 meters.  With an antenna on, it's fine for my operating; I'm not going to try to do very-weak-signal work with WWII gear.  So the fiddling continues.  Probably will add more ferrites and see how that does.  Even if it stays at this weak level, CW and Phone are it's a fair trade for such a simple regulated B+ supply, IMHO.  

Here is the High-Freq RAX with the supply I just built, tuning 7-10 Mc.  The nasty hash you hear on AM is *not* the converter; it's a bad line noise I need to run down.  The only place you can hear weak birdies is when I tune across about 8.5-9.5 MC (yes, the top end of the band isn't yet calibrated correctly).  Going to see if a bit more ferrite will kill this "leak" in my shielding.
https://photos.app.goo.gl/mnG1oGBY6ZKrqoJq1

Just for fun, here is a short video of all three.  The LF/MF is running on the DC-DC supply from last week, the center rig on a dynamotor, and the High-Freq on the right is on the pwr supply we're discussing.
https://photos.app.goo.gl/ZWpN7pDKUz8o2Osw2

More to follow.  Going to try one of these out running an SCR-183 transmitter.

GL OM DE Dave AB5S