comparison: content/hp8662a_3.rst
content/hp8662a_3.rst
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| 9 :series_index: 3 | 9 :series_index: 3 |
| 10 | 10 |
| 11 | 11 |
| 12 This is the part 3 on my series about my HP 8662A Signal Generator, and is | 12 This is the part 3 on my series about my HP 8662A Signal Generator, and is |
| 13 about the third main problems I found with this unit, as evocated in `part | 13 about the third main problems I found with this unit, as evocated in `part |
| 14 2 <{static}hp8662a_2.rst>`_: Error 04 is lit and there are some very | 14 2 <{filename}/hp8662a_2.rst>`_: Error 04 is lit and there are some very |
| 15 unpleasant spectrums at some frequencies. | 15 unpleasant spectrums at some frequencies. |
| 16 | 16 |
| 17 | 17 |
| 18 Low Fequency Section | 18 Low Fequency Section |
| 19 ==================== | 19 ==================== |
| 22 also work), it also gives an Error 04, which is described in the Service Manual | 22 also work), it also gives an Error 04, which is described in the Service Manual |
| 23 as "Sum Loop Unlocked (Low Frequency Section)", and the troubleshooting | 23 as "Sum Loop Unlocked (Low Frequency Section)", and the troubleshooting |
| 24 procedure to follow in on the Service Sheet H. The general block diagram of | 24 procedure to follow in on the Service Sheet H. The general block diagram of |
| 25 this section is as follow: | 25 this section is as follow: |
| 26 | 26 |
| 27 .. image:: {static}images/hp8662a/LF_block_diagram.png | 27 .. image:: {static}/images/hp8662a/LF_block_diagram.png |
| 28 :class: image-process-large-photo | 28 :class: image-process-large-photo |
| 29 | 29 |
| 30 This Low Frequency Section consists in no less than 4 phase locked loops in | 30 This Low Frequency Section consists in no less than 4 phase locked loops in |
| 31 order to achieve adjustable frequency synthesis with the expected stability and | 31 order to achieve adjustable frequency synthesis with the expected stability and |
| 32 resolution. | 32 resolution. |
| 35 frequency doubler nor the down converter are in the signal path (that is, when | 35 frequency doubler nor the down converter are in the signal path (that is, when |
| 36 the frequency range is between 120MHz and 640MHz). The frequency display | 36 the frequency range is between 120MHz and 640MHz). The frequency display |
| 37 consists in 11 digits, named DF0 to DF10, which are segmented to control | 37 consists in 11 digits, named DF0 to DF10, which are segmented to control |
| 38 several sets of PLLs: | 38 several sets of PLLs: |
| 39 | 39 |
| 40 :DF0 - DF2: are the fractional part of the fractional N-Loop (.1Hz, 1Hz and | 40 ========= ===================================================================== |
| 41 10Hz digits), | 41 :DF0-DF2: are the fractional part of the fractional N-Loop (.1Hz, 1Hz and |
| 42 | 42 10Hz digits), |
| 43 :DF3 - DF5: are the integer part of the fractional N-loop (100Hz, 1kHz and | 43 --------- --------------------------------------------------------------------- |
| 44 10kHz resolutions) | 44 :DF3-DF5: are the integer part of the fractional N-loop (100Hz, 1kHz and |
| 45 | 45 10kHz resolutions) |
| 46 :DF6 - DF7: are used to set the pretune VCO value for the sum loop VCO (A3A7), | 46 --------- --------------------------------------------------------------------- |
| 47 the FM sum loop VCO (A3A8) as well as the N-Loop VCO (A3A4). These | 47 :DF6-DF7: are used to set the pretune VCO value for the sum loop VCO (A3A7), |
| 48 are the 0.1MHz and 1MHz resolution digits. | 48 the FM sum loop VCO (A3A8) as well as the N-Loop VCO (A3A4). These |
| 49 | 49 are the 0.1MHz and 1MHz resolution digits. |
| 50 :DF8 - DF9: these control the high frequency section (DF10 can only be 0 or 1, | 50 --------- --------------------------------------------------------------------- |
| 51 in which case the frequency doubler is used). | 51 :DF8-DF9: these control the high frequency section (DF10 can only be 0 or 1, |
| 52 in which case the frequency doubler is used). | |
| 53 ========= ===================================================================== | |
| 52 | 54 |
| 53 | 55 |
| 54 Here is a more detailed vue of the block diagram of the low frequency section: | 56 Here is a more detailed vue of the block diagram of the low frequency section: |
| 55 | 57 |
| 56 .. image:: {static}images/hp8662a/sheet_H.png | 58 .. image:: {static}/images/hp8662a/sheet_H.png |
| 57 :class: image-process-large-photo | 59 :class: image-process-large-photo |
| 58 | 60 |
| 59 | 61 |
| 60 Fixing the Error 04 | 62 Fixing the Error 04 |
| 61 =================== | 63 =================== |
