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Looking for comments on speaker cloth
#19

Here's an update on this one. This is how it finally ended up looking. The color is a little off it's under fluorescent light. Oh and those knobs cost me $50 I just happened to find them on ebay.     

And here's the circuit mods. (This is one messy looking schematic even before I scribbled all over it.) 
First of all it's a farm radio 6 volts DC.  I am thinking how to power up this beast. The vibrator is no good. First I tried cleaning the contacts but to no avail.

Next I am thinking to build a switching unit to replace the vibrator. But this still needs a power supply.

Then it occurred to me why do I need a switcher when I want to run the radio on 120vac. What if I put 6vac to the primary of the step up transformer and see what comes out. And this worked, in fact it worked too well.  (And this is with a small 1.5 amp filament transformer). So I added a dropping resistor to keep the B+ voltage down. It went on the 120vac side of things.  I also added two diodes to the secondary side to take the place of the switching of the vibrator.

Next I added a bridge rectifier for the filaments and a dc to dc boost to run a string of LEDs for the dial. It had no dial light. 

And lastly tried a string of Zenners for a high voltage clamp while the tubes warm up. It worked like a charm. I hope they don't ever burn out. I know this is living dangerous. Now it's works pretty well. It's amazing how little power it needs.     

!!!!!!!!!!!!!!!!!!!RESISTANCE IS FUTILE!!!!!!!!!!!!!!!!!!!!!!  
                           /\/\/\/\/\/\/\/\/\
                                                     
                                 [Image: http://philcoradio.com/phorum/images/smi...on_eek.gif]  Chris


Messages In This Thread
Looking for comments on speaker cloth - by OZ4 - 03-24-2018, 01:53 PM
RE: Looking for comments on speaker cloth - by OZ4 - 01-09-2021, 05:51 PM



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