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Author Topic: PFR-3 Almost Done...Help  (Read 2773 times)
WE2F
Member

Posts: 32




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« on: July 10, 2013, 06:52:58 PM »

All,

I'll almost done! But, the RX is extremely weak. I pulled the L1 toroid and rescaraped and re-tinned the leads, RX came up significantly, but it was still weak. Then I noticed that when I touch the toroid during RX, it is perfect. What does that mean? How do I fix it? I'm a total kit-building and electronics new so I'm kind of swimming here. Any help would be greatly appreciated. Also, while I'm primarily interested in getting this rig working properly, I'm also very interested in understanding the issue, so if it happens again, I have some idea where to look and what to look for. Thanks in advance.

WE2F
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WE2F
Member

Posts: 32




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« Reply #1 on: July 10, 2013, 10:26:52 PM »

Whew, problem solved. Thanks to Steven Weber KD1JV, I found a crossed wire that was bypassing the tuning capacitor. Now she is receiving like a champ.

Still, I'm unclear as to why touching the other toroid would boost the receiver. If anyone could point me toward some learning on that, I would really appreciate it. Thanks and 73.
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KB4QAA
Member

Posts: 2260




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« Reply #2 on: July 11, 2013, 01:02:34 AM »

You changed the inductance with your body.
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WE2F
Member

Posts: 32




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« Reply #3 on: July 11, 2013, 05:47:44 AM »

Ah, that makes sense. I'm not sure why I didn't think about that. Thanks.
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K7KBN
Member

Posts: 2756




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« Reply #4 on: July 11, 2013, 04:54:47 PM »

Google the word "Theremin".  Then build one in time for Halloween!  Works on the same principle as your (former) problem: body capacitance.  Difference is that the Theremin is an audio device (basically).
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73
Pat K7KBN
CWO4 USNR Ret.
WE2F
Member

Posts: 32




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« Reply #5 on: July 12, 2013, 04:56:32 AM »

Very cool. Thanks for pointing me to the Theremin. As my family is extremely musical, building one could be extra fun. I can't believe that I never heard of one before.

This is why I love this hobby so much, there is so much to explore.
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