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Topic: PTT OUTPUT? (Read 1545 times)
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WM0I
Neuling
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Posts: 5
Ich liebe dieses Forum!
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PTT OUTPUT?
« on: 09. February 2018, 23:21:36 »
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I have been looking at the Schematic and the the new 2.8.0 firmware for any clue on how to have a PTT output when transmitting to key those small 50 to 100 watt amplifiers. Anyone know how to get a 0 volt to 5 volt transition when in TX mode?
Best regards
Richard WM0I
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| « Last Edit: 10. February 2018, 00:26:14 by WM0I » |
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peter_77
Urgestein
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Posts: 735
THE mcHF and UHSDR forum !
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Re:PTT OUTPUT?
« Reply #2 on: 10. February 2018, 13:28:41 »
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Here is a solution (DF5LI's diagram) which works perfectly fine:
https://www.amateurfunk-sulingen.de/forum/index.php?board=15;action=display;threadid=687;start=15
Following thread entries also describe the somehow better solution in replacing the optocoupler with a semiconductor relais PANASONIC AQV255GSX like Andreas mentioned above.
Unfortunately the thread requires Google translator 
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| « Last Edit: 10. February 2018, 13:32:44 by peter_77 » |
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DF5LI
alter Hase
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Posts: 371
Ich liebe meinen SParrow !
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Re:PTT OUTPUT?
« Reply #3 on: 10. February 2018, 15:15:03 »
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But all this solutions are mor or less open collector-switcher to ground. A transition from zero to 5 volt in transmit mode is not so easy to manage. If you are looking at the schematic, you can find pin 1 at U7 (72HTC02), which will have the desired behavior. But be careful, this pin cannot deliver much current...
And your problem is not firmware-related.
edit by Mod: correct!
Thread verschoben
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| « Last Edit: 10. February 2018, 16:12:32 by DL8EBD » |
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73, Harri
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