ARROW uBITX Group Purchase: Difference between revisions
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Huge resource page by ZL1AXG: http://ubitx.net/ | Huge resource page by ZL1AXG: http://ubitx.net/ | ||
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'''Problems, Issues and Glitches''' - significant issues reported by builders | '''Problems, Issues and Glitches''' - significant issues reported by builders | ||
* TDA2822 stereo amplifier high failure rate | * TDA2822 stereo amplifier high failure rate | ||
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* Power output differences across bands | * Power output differences across bands | ||
** http://ubitx.net/fix-fix-uneven-tx-output-across-bands/ | ** http://ubitx.net/fix-fix-uneven-tx-output-across-bands/ | ||
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'''Building Hints and Tips''' | '''Building Hints and Tips''' | ||
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'''Recommended Mods''' | '''Recommended Mods''' | ||
* KD8CEC software | * KD8CEC software | ||
** http://www.hamskey.com/ | ** http://www.hamskey.com/ | ||
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'''Advanced Mods''' | '''Advanced Mods''' | ||
* AGC circuit | * AGC circuit | ||
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***... Full range integrated Passband (front end through audio section)...Benefit: True AGC on all levels, no overload or distortion of any stage. AGC signal for "s" meter (can be calibrated to real signal strength by reference).Bad: Very complicated, impacts every RF/IF/Audio stage. Lots of mods and parts.Comment: A CW ops dream. | ***... Full range integrated Passband (front end through audio section)...Benefit: True AGC on all levels, no overload or distortion of any stage. AGC signal for "s" meter (can be calibrated to real signal strength by reference).Bad: Very complicated, impacts every RF/IF/Audio stage. Lots of mods and parts.Comment: A CW ops dream. | ||
* KD2NDR port to Teensy | * KD2NDR port to Teensy | ||
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'''Enclosure Ideas''' | '''Enclosure Ideas''' | ||
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'''ARROW Rig Showcase''' | '''ARROW Rig Showcase''' | ||
Revision as of 19:23, 28 March 2018
Things related to the uBITX radio group purchase made by a number of ARROW members.
Huge resource page by ZL1AXG: http://ubitx.net/
Problems, Issues and Glitches - significant issues reported by builders
- TDA2822 stereo amplifier high failure rate
- Reported on the mailing list, Some ideas discussed there:
- Replace with 8-pin socket and NJM2073D
- LM386 + adaptor
- <link(s) to best discussion(s), fix(es), etc(es)>
- Reported on the mailing list, Some ideas discussed there:
- Power output differences across bands
Building Hints and Tips
Recommended Mods
- KD8CEC software
Advanced Mods
- AGC circuit
- K9HZ summary of options
- ... audio range passband...Benefit: saves your ears, $0.02 diode, trivially easy to implement.Bad: only protects your ears... not RF sections from excessive signal and overload. Not a true AGC signal for "s" meter, only an audio strength.Comment: Save the $0.02 diode, turn the damn volume down and live with the IF overload.
- ... IF range passband...Benefit: Saves ears, prevents IF overload, AGC signal for "s" meter (can be calibrated to real signal strength by reference).Bad: More complicated/ more parts, RF level attenuator and AGC response, more expensive than the $0.02 diode,Comment: can be triggered by anything in the passband and that can be good and bad.
- ... Full range integrated Passband (front end through audio section)...Benefit: True AGC on all levels, no overload or distortion of any stage. AGC signal for "s" meter (can be calibrated to real signal strength by reference).Bad: Very complicated, impacts every RF/IF/Audio stage. Lots of mods and parts.Comment: A CW ops dream.
- K9HZ summary of options
- KD2NDR port to Teensy
Enclosure Ideas
ARROW Rig Showcase