Apollo - Development Discussion

Rev 1A, page 1, of the Apollo schematic. Click for larger images.

The initial APOLLO schematic is available for comment and suggestions are desired. Please place them here or email to the mailing list hpsdr@lists.openhpsdr.org or direct email to Kjell Karlsen

Rev 1A, page 2, of the Apollo schematic. Click for larger images.

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Update 18 December 2009, here is a high resolution picture of Kjell's alpha Apollo board, looking very good :)

High Res Alpha.jpg.

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Update 16 December 2009, the latest schematics can be found here : PDF Rev 1D Schematic.

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• The New PDF version of the schematic is here: PDF Rev 1A Schematic.

• The Silkscreen Top here: Silkscreen Top, Rev 1A.

• The Silkscreen Bottom is here: Silkscreen Bottom, Rev 1A.

• The PCB Top here: PCB Top, Rev 1A.

• The PCB Bottom is here: PCB Bottom, Rev 1A.

Added for LA2NI, Kjell by -- KV0S, Dave 16:38, 10 October 2009 (UTC)

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The original PDF version of the schematic is here: PDF rev 0 Schematic.

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Three comments:

1. I believe the interface is SPI rather than I2C for the TPIC595 latches.
2. 74HC14 can be used in lieu of 74HC04. The '14 has Schmitt trigger inputs, might help with noise immunity on the control line(s).
3. Suggest considering PIN diode antenna switching instead of a relay (RL15). For those who operate CW QSK, quiet is nice. It's even nice for those who don't :-). KK7P 21:22, 14 June 2009 (UTC)

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Another comment: An Elecraft T-1 could also be accommodated at these power levels as an alternative to the suggested LDG. Disclaimer: I work for Elecraft. KK7P 05:02 31 July 2009 (UTC)