Log in
Register
Menu
Log in
Register
Home
What's new
Latest activity
Authors
Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Current visitors
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Miscellaneous Sections
Tech Head - The Technology Section
The Work Bench and Soldering Station
Schematic for Echostar AD3000ip LNB switching circuit
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Llew" data-source="post: 462486" data-attributes="member: 175007"><p>Always worth trying to keep the old box working - (within its limitations, channel capacity etc). But then I only really use it for dish positioning.</p><p></p><p>Later receivers than this Echostar have a dedicated LNB switching chip that provides the H/V voltages; this one just uses basic easily available or substitute components.</p><p></p><p>I couldn't at first work out how the 12V regulator U901 was able to supply the 13/18V to the LNB, as what is normally the ground terminal fixes the output at 12V.</p><p></p><p>In this circuit this terminal is raised through Q909 to 1V or 6V, which will give 12V+1V=13V or 12V+6V=18V to the LNB.</p><p></p><p>I was thrown by the fact that the fault I had (shorted Q909) earthed the ground terminal of U901!</p><p></p><p>Llew</p></blockquote><p></p>
[QUOTE="Llew, post: 462486, member: 175007"] Always worth trying to keep the old box working - (within its limitations, channel capacity etc). But then I only really use it for dish positioning. Later receivers than this Echostar have a dedicated LNB switching chip that provides the H/V voltages; this one just uses basic easily available or substitute components. I couldn't at first work out how the 12V regulator U901 was able to supply the 13/18V to the LNB, as what is normally the ground terminal fixes the output at 12V. In this circuit this terminal is raised through Q909 to 1V or 6V, which will give 12V+1V=13V or 12V+6V=18V to the LNB. I was thrown by the fact that the fault I had (shorted Q909) earthed the ground terminal of U901! Llew [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Miscellaneous Sections
Tech Head - The Technology Section
The Work Bench and Soldering Station
Schematic for Echostar AD3000ip LNB switching circuit
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top