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27th Dec 2018, 2:39 pm | #1 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
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Yet another 'Pantry' tx
Hi all!
I got very board recently and drew out this circuit which I've been using for decades. It's much simpler than it looks. The main circuit is U2 Q1, Q2 and Q3. All the following are just embellishments:
It's appropriate now that I investigated a modern programmable and much cheaper substitute for the crystal oscillator. Medium wave is going to get louder with interference, and quieter with stations. I think it's time to think ahead... Season's greetings, Ian |
27th Dec 2018, 2:52 pm | #2 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,224
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Re: Yet another 'Pantry' tx
Why is there no feedback on U1 (or U3, but the latter could be intended to saturate)?
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27th Dec 2018, 3:02 pm | #3 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
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Re: Yet another 'Pantry' tx
If you upload the diagram as a PDF document, it won't be resized so will be easier to read.
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27th Dec 2018, 3:05 pm | #4 | |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
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Re: Yet another 'Pantry' tx
Quote:
I shamelessly lifted those two circuits from '50 circuits using IC 3130'. Just found an online copy here: https://www.americanradiohistory.com...-ic-ca3130.pdf Ian |
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27th Dec 2018, 3:09 pm | #5 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,224
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Re: Yet another 'Pantry' tx
Is there supposed to be a connection from the output of U1 (pin 6) to the left hand end of C5/R3 in the diagram? It's not visible (but may have been lost in the re-sizing).
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27th Dec 2018, 3:27 pm | #6 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
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Re: Yet another 'Pantry' tx
Think I've pdf'd it!
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27th Dec 2018, 3:29 pm | #7 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
|
Re: Yet another 'Pantry' tx
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27th Dec 2018, 4:33 pm | #8 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
|
Re: Yet another 'Pantry' tx
I missed the editing time window, so 've corrected my drawing error which Tony noticed. (Thanks Tony.)
New .pdf attached. |