https://tabletop.martinos.org/index.php?title=Hardware:RF&feed=atom&action=history Hardware:RF - Revision history 2024-03-28T17:53:49Z Revision history for this page on the wiki MediaWiki 1.35.1 https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=824&oldid=prev Jaystock at 16:53, 19 May 2022 2022-05-19T16:53:01Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:53, 19 May 2022</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l20" >Line 20:</td> <td colspan="2" class="diff-lineno">Line 20:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF pulse created by the Medusa console is amplified by a 1,2W broadband RF power amplifier (MiniCircuits ZHL-3A).  Because we had some trouble with the carrier frequency coming through the transmit side even when the pulse was &quot;off&quot; at the console, we found we needed to gate the power to the ZHL-3A using the gating pulse from the console so that the ZHL-3A only receives power during the RF pulse.  This also prevents the ZHL-3A from dissipating heat between RF pulses.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF pulse created by the Medusa console is amplified by a 1,2W broadband RF power amplifier (MiniCircuits ZHL-3A).  Because we had some trouble with the carrier frequency coming through the transmit side even when the pulse was &quot;off&quot; at the console, we found we needed to gate the power to the ZHL-3A using the gating pulse from the console so that the ZHL-3A only receives power during the RF pulse.  This also prevents the ZHL-3A from dissipating heat between RF pulses.</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">As an alternative RFPA, we have also had success with the MHW592 Motorola RFPA.  We prepared an in-house PCB daughter board to house the MWH592 module. The board can be downloaded [http://rflab.martinos.org/index.php?title=Low-cost_1_Watt_RF_power_amplifier_(in_progress) at this link].  The MHW592 is an obsolete component but is still available from vendors on eBay, etc.  This RFPA provides faster power-on times for unblanking using our simple unblanking method of cutting power to the RFPA module with a TIP32 transistor.</ins></div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=664&oldid=prev Jaystock at 16:31, 6 April 2017 2017-04-06T16:31:50Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:31, 6 April 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l5" >Line 5:</td> <td colspan="2" class="diff-lineno">Line 5:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.  The length of the solenoid is a tradeoff between B1 homogeneity (longer is better) and the size of the imaging volume.  If the solenoid is too long, signal from water outside the imaging volume that lies in the nonlinear region of the gradient coil field profile will warp into the image and cause artifacts.   </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.  The length of the solenoid is a tradeoff between B1 homogeneity (longer is better) and the size of the imaging volume.  If the solenoid is too long, signal from water outside the imaging volume that lies in the nonlinear region of the gradient coil field profile will warp into the image and cause artifacts.   </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size:  ~7 turns of wire, 14mm dia. along X, 11mm length along Y direction.]]</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size:  ~7 turns of wire, 14mm dia. along X, 11mm length along Y direction<ins class="diffchange diffchange-inline">.  Teflon tubing is used around the wire to set the spacing between turns</ins>.]]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=663&oldid=prev Jaystock at 16:30, 6 April 2017 2017-04-06T16:30:39Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:30, 6 April 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l5" >Line 5:</td> <td colspan="2" class="diff-lineno">Line 5:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.  The length of the solenoid is a tradeoff between B1 homogeneity (longer is better) and the size of the imaging volume.  If the solenoid is too long, signal from water outside the imaging volume that lies in the nonlinear region of the gradient coil field profile will warp into the image and cause artifacts.   </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.  The length of the solenoid is a tradeoff between B1 homogeneity (longer is better) and the size of the imaging volume.  If the solenoid is too long, signal from water outside the imaging volume that lies in the nonlinear region of the gradient coil field profile will warp into the image and cause artifacts.   </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size.]]</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size<ins class="diffchange diffchange-inline">:  ~7 turns of wire, 14mm dia. along X, 11mm length along Y direction</ins>.]]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=662&oldid=prev Jaystock at 16:29, 6 April 2017 2017-04-06T16:29:12Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:29, 6 April 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l3" >Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:rfcoil.jpg|400px|thumb|right|RF coil in copper shielded box]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:rfcoil.jpg|400px|thumb|right|RF coil in copper shielded box]]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources. <ins class="diffchange diffchange-inline"> The length of the solenoid is a tradeoff between B1 homogeneity (longer is better) and the size of the imaging volume.  If the solenoid is too long, signal from water outside the imaging volume that lies in the nonlinear region of the gradient coil field profile will warp into the image and cause artifacts.  </ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size.]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size.]]</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=661&oldid=prev Jaystock at 16:27, 6 April 2017 2017-04-06T16:27:33Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:27, 6 April 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1" >Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''RF Coil'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''RF Coil'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:rfcoil.jpg|<del class="diffchange diffchange-inline">600px</del>|thumb|right|RF coil in copper shielded box]]</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:rfcoil.jpg|<ins class="diffchange diffchange-inline">400px</ins>|thumb|right|RF coil in copper shielded box]]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The RF coil for this system is used for transmitting the excitation pulse to get the magnetization precessing and to detect the MRI signal thru the Faraday detection principle.  The coil is part of a resonant circuit that is tuned to the Larmor frequency of the B0 magnet.  The coil is a solenoid which the NMR tubes fit into snuggly; it is contained in a plastic case which is wrapped in copper foil to shield against external RF noise sources.</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[[File:IMG_7652.JPG|400px|thumb|right|Close-up of RF coil showing approx. size.]]</ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=642&oldid=prev Jaystock at 15:16, 29 September 2016 2016-09-29T15:16:24Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:16, 29 September 2016</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l12" >Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Receive amplifier'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Receive amplifier'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The NMR signal from the coil is very small, so a a pre-amplifier with a low noise figure is needed as the receive amplifier.  A 2 stage amplifier was designed using [http://www.minicircuits.com/pdfs/GALI-74+.pdf Gali-74+ Monolithic Amplifier] from Minicircuits.  The TR switch and pre-amplifier circuit were combined in a single PCB.  [https://tabletop.martinos.org/images/4/48/TR_switch_and_preamp.zip Click here] to download the Eagle board files for the TR Switch.</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The NMR signal from the coil is very small, so a a pre-amplifier with a low noise figure is needed as the receive amplifier.  A 2 stage amplifier was designed using [http://www.minicircuits.com/pdfs/GALI-74+.pdf Gali-74+ Monolithic Amplifier] from Minicircuits.  The TR switch and pre-amplifier circuit were combined in a single PCB.  [https://tabletop.martinos.org/images/4/48/TR_switch_and_preamp.zip Click here] to download the Eagle board files for the TR Switch <ins class="diffchange diffchange-inline">PCB</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=641&oldid=prev Jaystock at 15:12, 29 September 2016 2016-09-29T15:12:34Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:12, 29 September 2016</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l12" >Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Receive amplifier'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Receive amplifier'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The NMR signal from the coil is very small, so a a pre-amplifier with a low noise figure is needed as the receive amplifier.  A 2 stage amplifier was designed using [http://www.minicircuits.com/pdfs/GALI-74+.pdf Gali-74+ Monolithic Amplifier] from Minicircuits.  The TR switch and pre-amplifier circuit were combined in a single PCB.</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The NMR signal from the coil is very small, so a a pre-amplifier with a low noise figure is needed as the receive amplifier.  A 2 stage amplifier was designed using [http://www.minicircuits.com/pdfs/GALI-74+.pdf Gali-74+ Monolithic Amplifier] from Minicircuits.  The TR switch and pre-amplifier circuit were combined in a single PCB<ins class="diffchange diffchange-inline">.  [https://tabletop.martinos.org/images/4/48/TR_switch_and_preamp.zip Click here] to download the Eagle board files for the TR Switch</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=567&oldid=prev Jaystock at 21:31, 8 October 2015 2015-10-08T21:31:19Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 21:31, 8 October 2015</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l7" >Line 7:</td> <td colspan="2" class="diff-lineno">Line 7:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The RF coil is used for 2 things: transmitting the RF pulse and receiving the MRI signal.  This means that it should sometimes be connected to the transmit amplifier and sometimes be connected to the receive amplifier.  This TR switch uses pin diodes and a lumped quarterwave line to effectively switch the coil connection between the two amplifiers, as shown in  [https://<del class="diffchange diffchange-inline">gate</del>.<del class="diffchange diffchange-inline">nmr</del>.<del class="diffchange diffchange-inline">mgh.harvard.edu</del>/<del class="diffchange diffchange-inline">wiki</del>/<del class="diffchange diffchange-inline">Tabletop_MRI</del>/<del class="diffchange diffchange-inline">index.php</del>/<del class="diffchange diffchange-inline">File:</del>Picture1.png <del class="diffchange diffchange-inline"> </del>this schematic diagram].</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The RF coil is used for 2 things: transmitting the RF pulse and receiving the MRI signal.  This means that it should sometimes be connected to the transmit amplifier and sometimes be connected to the receive amplifier.  This TR switch uses pin diodes and a lumped quarterwave line to effectively switch the coil connection between the two amplifiers, as shown in  [https://<ins class="diffchange diffchange-inline">tabletop</ins>.<ins class="diffchange diffchange-inline">martinos</ins>.<ins class="diffchange diffchange-inline">org</ins>/<ins class="diffchange diffchange-inline">images</ins>/<ins class="diffchange diffchange-inline">1</ins>/<ins class="diffchange diffchange-inline">1b</ins>/Picture1.png this schematic diagram].</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> </table> Jaystock https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=386&oldid=prev Cooley at 22:49, 13 May 2014 2014-05-13T22:49:41Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 22:49, 13 May 2014</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l7" >Line 7:</td> <td colspan="2" class="diff-lineno">Line 7:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''TR Switch'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The RF coil is used for 2 things: transmitting the RF pulse and receiving the MRI signal.  This means that it should sometimes be connected to the transmit amplifier and sometimes be connected to the receive amplifier.  This TR switch uses pin diodes and a lumped quarterwave line to effectively switch the coil connection between the two amplifiers, as shown in  [https://gate.nmr.mgh.harvard.edu/wiki/Tabletop_MRI/<del class="diffchange diffchange-inline">images/0/08</del>/<del class="diffchange diffchange-inline">Tr_switch_schematic</del>.<del class="diffchange diffchange-inline">pdf </del> this schematic diagram].</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The RF coil is used for 2 things: transmitting the RF pulse and receiving the MRI signal.  This means that it should sometimes be connected to the transmit amplifier and sometimes be connected to the receive amplifier.  This TR switch uses pin diodes and a lumped quarterwave line to effectively switch the coil connection between the two amplifiers, as shown in  [https://gate.nmr.mgh.harvard.edu/wiki/Tabletop_MRI/<ins class="diffchange diffchange-inline">index.php</ins>/<ins class="diffchange diffchange-inline">File:Picture1</ins>.<ins class="diffchange diffchange-inline">png </ins> this schematic diagram].</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> </table> Cooley https://tabletop.martinos.org/index.php?title=Hardware:RF&diff=226&oldid=prev Wald at 18:11, 22 August 2013 2013-08-22T18:11:08Z <p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:11, 22 August 2013</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l17" >Line 17:</td> <td colspan="2" class="diff-lineno">Line 17:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Power amplifier'''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Power amplifier'''</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The RF pulse created by the Medusa console is amplified by a <del class="diffchange diffchange-inline">1W </del>broadband RF power amplifier (MiniCircuits ZHL-<del class="diffchange diffchange-inline">1A</del>).  Because we had some trouble with the carrier frequency coming through the transmit side even when the pulse was &quot;off&quot; at the console, we found we needed to gate the power to the ZHL-<del class="diffchange diffchange-inline">1A </del>using the gating pulse from the console so that the ZHL-<del class="diffchange diffchange-inline">1A </del>only receives power during the RF pulse.  This also prevents the ZHL-<del class="diffchange diffchange-inline">1A </del>from <del class="diffchange diffchange-inline">disappating </del>heat between RF pulses.</div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The RF pulse created by the Medusa console is amplified by a <ins class="diffchange diffchange-inline">1,2W </ins>broadband RF power amplifier (MiniCircuits ZHL-<ins class="diffchange diffchange-inline">3A</ins>).  Because we had some trouble with the carrier frequency coming through the transmit side even when the pulse was &quot;off&quot; at the console, we found we needed to gate the power to the ZHL-<ins class="diffchange diffchange-inline">3A </ins>using the gating pulse from the console so that the ZHL-<ins class="diffchange diffchange-inline">3A </ins>only receives power during the RF pulse.  This also prevents the ZHL-<ins class="diffchange diffchange-inline">3A </ins>from <ins class="diffchange diffchange-inline">dissipating </ins>heat between RF pulses.</div></td></tr> </table> Wald