diff options
Diffstat (limited to 'README-4m.md')
| -rw-r--r-- | README-4m.md | 45 |
1 files changed, 13 insertions, 32 deletions
diff --git a/README-4m.md b/README-4m.md index 7f52450..cc129aa 100644 --- a/README-4m.md +++ b/README-4m.md @@ -3,40 +3,21 @@ DART-70 In 2023, the 70MHz band became accessible to amateurs in Switzerland. This offers an excuse to build a transciever. -* Separate things a bit more than on Picardy 2020 - * One HF SSB/CW exciter PCB with: - * Voltage regulators - * Mic input from Picardy 2020 - * AGC measurement like Picardy 2020 - * AGC IF amp better than Picardy 2020 - * VEXIBITX applies AGC at HF input instead, and uses uBitx amplifiers for IF - * uBitx has no AGC - * Hybrid Cascode? (Implies IF between 8 and 12 MHz) - * Frequency plan: - * What HF intermediate frequency? - * High-side mixing? need low-pass to reject image, also rejects FMBC - * 96MHz oscillator: 26MHz IF - * Low-side mixing (kuhne and anglian do that) - * 42MHz oscillator: 28MHz IF - * Prefer, can't be wrong if others do that - * Reuse Anglian 3L oscillator from lo_board/lo_board.pro - * VFOs Si5351A-B-GT for first two mixers - * Mixers (3 needed: VHF, HF, AF) - * AF: like VEXIBITX - * HF: like uBitx (BAT68-04W ring mixer, see doc/ubitxv6.{txt,pdf}) - * VHF: MCL RMS-11X (+7dBm LO) or the macom one? (missing from inventory) - * XTAL filter QER like uBITX at 11.0592 MHz - * One PCB with HF-4m transverter, inspired by Anglian - * One PCB with 4m driver, PA and antenna switching - * We are allowed 25W ERP, aim for 10W PEP - * BCW71 driver, 2SCR573D3 push-pull amp? - * How about STN4NF20L? - * LNA: SPF5189Z - * One PCB for frontend - * Connected by cable to the main board - * Microcontroller, Display, Encoder +See dart70-blockdiagram.pdf + * Enclosure: Hammond 1411R or 513-0900? +Receive gain: + +S9 is -93dBm, S1 is -141dBm + +-141 -1 +16 -1 -7 -4 +60 -7 +30 = -55 dBm + + +Transmit gain: + +-6 -7 -4 +16 -4 -7 -1 -1 +15 +15 +15 -1 = 30 dBm + ## To order * Enclosure |