Added new assembly manual v1.1, containing instruction for PA direct biasing method.

README.md

@@ -5,9 +5,9 @@ The SSB transmit-stage is implemented entirely in digital and software-based man
 
 For the receiver, a large portion of the original QCX circuit has been removed and implemented in digital manner (software): the ATMEGA328P is now implementing the 90 degree phase shift circuit, the (CW/SSB) filter circuit and the audio amplifier circuit (now a class-D amplifier). This has simplified the QCX circuit a lot (50% less components needed), and there are a number of advantages and features: there is no longer a need for an alignment procedure due to the very accurate 90 degree Hilbert phase shifter; and there are now adjustable IF DSP filters for CW and SSB; and there is an AGC and there is a noise-reducing DSP signal conditioning function and there are three indepent built-in attenuators in the analog front-end which helps utilizing the full dynamic range. The speaker is directly connected and driven by the ATMEGA. A digital mixer with narrow low-pass window (2 kHz), steep roll-off (-45dB/decade) combined with an oversampling and decimating ADC are responsible for a processing gain, dynamic range and alias rejection sufficient to handle weak and strong signal conditions (e.g. contests or listening on 40m just next to broadcasting band).
 
-This experiment is created to try out what is can be achieved with minimal hardware while moving complexity towards software; here the approach followed is to simplify the design where possible while keep a reasonable performance. The result is a cheap, easy to build, versatile QRP SSB transceiver that actually is quite suitable for making QSOs (even in contest situations), however due to the experimental nature some parts are still in progress and hence limited. Feel free to try it out or to experiment with this sketch, let me know your thoughts or contribute here: https://github.com/threeme3/QCX-SSB  There is a forum discussion on the topic here: [QRPLabs Forum]
+This experiment is created to try out what is can be achieved with minimal hardware while moving complexity towards software; here the approach followed is to simplify the design where possible while keep a reasonable performance. The result is a cheap, easy to build, versatile QRP SSB transceiver that actually is quite suitable for making QSOs (even in contest situations), however due to the experimental nature some parts are still in progress and hence limited. Feel free to try it out or to experiment with this sketch, let me know your thoughts or contribute here: https://github.com/threeme3/QCX-SSB  The original forum discussion on the topic here: [QRPLabs Forum]
 
-FYI: Recently, a new group of people with similar interest has started a collaboration to build a lightweight, small, portable (SOTA) rig for the summer. It is based on ideas here, you can here find link to the [Forum].
+**Update: A new group with collaborative interest has started to build a compact, portable (SOTA) rig for the summer, based on the ideas presented here. More information can be found in this: [Forum].**
 
 73, Guido
 pe1nnz@amsat.org
@@ -51,7 +51,7 @@ Below the schematic after the modification is applied, unused components are lef
 
 
 ## Installation:
-Please find here the latest **[PCB Rev5 Assembly Manual CLICK HERE] by Manuel, DL2MAN (document revision 1.02), 20-May-2020**, instructions for older PCB revisions can be found below:
+Please find here the latest **[PCB Rev5 Assembly Manual CLICK HERE] by Manuel, DL2MAN (document revision 1.1), 23-May-2020**. Instruction for older PCB revisions can be found below:
 
 This modification consists of a few component changes and wires:
 - **To simplify things, 79 components are no longer needed** (and you could omit them on an unbuilt QCX): IC6-10,R11-40,43,55,R59-64,C1,5,8,C9-28,C31,C52-54,L1-3,D5,Q7,T1,JP1/DVM/FREQ.
@@ -170,8 +170,7 @@ The following performance measurements were made with QCX-SSB R1.01, a modified
 
 
 ### Credits:
-[QCX] (QRP Labs CW Xcvr) is a kit designed by _Hans Summers (G0UPL)_, originally built for RSGB's YOTA summer camp 2017, a high performance, image rejecting DC transceiver; basically a simplified implementation of the [NorCal 2030] by _Dan Tayloe (N7VE)_ designed in 2004 combined with a [Hi-Per-Mite] Active Audio CW Filter by _David Cripe (NMØS)_, [Low Pass Filters] from _Ed (W3NQN)_ 1983 Articles, a key-shaping circuit by _Donald Huff (W6JL)_, a BS170 switched [CMOS driven MOSFET PA] architecture as used in the [ATS] designs by _Steven Weber (KD1JV)_ (originating from the [Power MOSFET revolution] in the mid 70s), and combined with popular components such as Atmel [ATMEGA328P] microprocessor, a Hitachi [HD44780] LCD display and a Silicon Labs [SI5351] Clock Generator (and using a [phase shift in the SI5351 clocks]). The [QCX-SSB] transmitter and QCX-SDR receiver stage both running on a ATMEGA328P, including its multiband front-end and direct PA biasing/envelope-generation technique; its concept, circuit, code and modification to run on a QCX are a design by _Guido (PE1NNZ)_; the software-based SSB transmit stage is a derivate of earlier experiments with a [digital SSB generation technique] on a Raspberry Pi. Many thanks to all of you who got interested in this project and took the challege and effort to try out QCX-SSB. Without your valuable feedback the project could not have kept moving on, improving and challenging new ideas!
-The detailed assembly manual for Rev 5 PCB, is the work of Manuel, DL2MAN (many thanks).
+[QCX] (QRP Labs CW Xcvr) is a kit designed by _Hans Summers (G0UPL)_, originally built for RSGB's YOTA summer camp 2017, a high performance, image rejecting DC transceiver; basically a simplified implementation of the [NorCal 2030] by _Dan Tayloe (N7VE)_ designed in 2004 combined with a [Hi-Per-Mite] Active Audio CW Filter by _David Cripe (NMØS)_, [Low Pass Filters] from _Ed (W3NQN)_ 1983 Articles, a key-shaping circuit by _Donald Huff (W6JL)_, a BS170 switched [CMOS driven MOSFET PA] architecture as used in the [ATS] designs by _Steven Weber (KD1JV)_ (originating from the [Power MOSFET revolution] in the mid 70s), and combined with popular components such as Atmel [ATMEGA328P] microprocessor, a Hitachi [HD44780] LCD display and a Silicon Labs [SI5351] Clock Generator (and using a [phase shift in the SI5351 clocks]). The [QCX-SSB] transmitter and QCX-SDR receiver stage both running on a ATMEGA328P, including its multiband front-end and direct PA biasing/envelope-generation technique; its concept, circuit, code and modification to run on a QCX are a design by _Guido (PE1NNZ)_; the software-based SSB transmit stage is a derivate of earlier experiments with a [digital SSB generation technique] on a Raspberry Pi. The assembly manual for the QCX Rev 5 PCB, is the work of _Manuel (DL2MAN)_. Many thanks to all of you who got interested in this project and took the challege and effort to try out QCX-SSB. Without your valuable feedback and contributions the project could not have kept moving on, improving and challenging new ideas!
 
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 ### References