content/10MHz_ref_2.rst

Tue, 28 Aug 2018 15:05:01 +0200

author
David Douard <david.douard@logilab.fr>
date
Tue, 28 Aug 2018 15:05:01 +0200
changeset 104
8396e709bde5
parent 43
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child 115
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permissions
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improve hgignore

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4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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1 ==========================================
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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2 Building a bench 10MHz reference: part 2
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3 ==========================================
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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4
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5 :author: David Douard
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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6 :Category: Electronics
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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7 :Tags: test equipment, 10MHz, Rubidium
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8 :series: 10MHz Bench Reference Standard
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9 :series_index: 2
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10
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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11 This is a quick follow-up of the `first part`_ of this series.
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12
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13 I've received a few parts from digikey, including a couple of 22µH
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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14 Sumida CLS62 inductors (I bought two of them in case I f**k up one of
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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15 them trying to solder it with my Weller WS50 iron).
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16
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17 Desoldering and soldering SMD parts without an air flow station is a
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18 bit tricky, but eventually I succeded in replacing the broken inductor.
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19
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20 .. image:: {filename}/images/freq_ref/extron_fixed.jpg
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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21 :alt: The Extron Video Distribution Amplifier fixed with a
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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22 new inductor for its small DC-DC converter.
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23
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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24 Now the "video" amplifier works like a charm. The 10MHz signal is
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25 nicely amplified:
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26
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27 .. image:: {filename}/images/freq_ref/extron_working_10MHz.jpg
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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28 :alt: The Extron Video Distribution Amplifier dispatching a
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29 10MHz signal to several equipments.
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30
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31 At 10Mhz, the amplifier dephase the signal of about 20ns (ie. 72
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32 deg). We can also note that (the input impedance of the Extron
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33 amplifier is set to 75 ohm, while my scope is at 1 Mohm; I should try
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34 using the input of my scope set at 50ohm) that the amplification
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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35 factor is exactly x2.
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36
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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37 .. image:: {filename}/images/freq_ref/extron_dephasing_10MHz.jpg
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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38 :alt: The Extron Video Distribution Amplifier dephasing at 10MHz.
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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39
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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40 What I need to check carefully now is if all the outputs of the
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41 amplifier are perfectly in phase.
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42
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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43 It's amusing that a few days ago, FlyingHacker_ did post a `new thread
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44 on the EEVBlog`_ forum in which he explain that he uses exactly the
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
David Douard <david.douard@logilab.fr>
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45 same distribution amplifier to provide a 10MHz reference to several
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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46 test equipments. Exactly what I have in mind with mine!
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47
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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48 One thing I will probably not do is adapting the input/output
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49 impedance (from 75 ohm to 50 ohm). I'm pretty sure it will work fine
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50 as is. We'll see if it provoque some side effects (especioally on the
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51 phase of the signal).
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52
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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53 .. _FlyingHacker: http://www.eevblog.com/forum/profile/?u=110591
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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54 .. _`new thread on the EEVBlog`: http://www.eevblog.com/forum/projects/distribution-amp-%28for-reference-frequency-standard-or-otherwise%29/msg893851/
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4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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56
4c3a05ba94de [10MHz] new small follow-up for the 10MHz freq reference series
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57 .. _`first part`: {filename}/10MHz_ref.rst

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