C Band Gregorian Dome Receiver Log
as of Sunday, 07-Sep-2008 21:53:54 ASTGo to Most Recent Entry
| Name | Date | Comment | |
|---|---|---|---|
| ANS | anolla@naic.edu | 10/7/99 | Problem: There is a helium leak in the cryo system. Correction: A leaky hose was founded in the supply line at the rotary floor, hose was tightening up and quit leaking. |
| ANS | anolla@naic.edu | 1/11/2000 | There was water condensed at the window of the recvr. Dewar .We recommend to add pressures to the horn to avoid this. |
| ANS | anolla@naic.edu | 2/4/2000 | System shutted off due to contamination.Need crosshead replacement. |
| ANS | anolla@naic.edu | 2/7/2000 | System cooled down.Crosshead ED 015 replaced with crosshead ED 013 due to contamination on cryo system. |
| ANS | anolla@naic.edu | 3/29/2000 | New auto shutter installed. Pneumatic type developed by Jose Vives. |
| ANS | anolla@naic.edu | 4/17/2000 | Pneumatic shutter removed due to problems with it. It was getting stocked due to faulty air compressor. |
| ANS | anolla@naic.edu | 6/8/2000 | Auto shutter installed again , isolation was checked but is it too poor , just 20 db. |
| ANS | anolla@naic.edu | 9/28/2000 | Receiver is hot due to a short ckt. At the cryo compressor (ED 001) The AC wiring at the power sw made a short ckt that melted a he line. |
| ANS | anolla@naic.edu | 10/10/2000 | Receiver had a bad RF amp on chann. A. It was replaced, Amp sn on chann A is C11 & in chann B is C12.The sn of the bad amp on chnn A was C10. |
| ANS | anolla@naic.edu | 10/11/2000 | Receiver cooled down.Chann A T Sys is 38 ºk & chann B is 32 ºk . |
| ANS | anolla@naic.edu | 10/25/2000 | Receiver crosshead replaced due to contamination on it , it came from la large helium loss in comp.Crosshead ED 013 replaced with ED 015. Then it is been cool with comp 010 , so it will be three 350 crossheads with this comp. |
| ANS | anolla@naic.edu | 11/2/2000 | After a week been run by comp. ED 010 the cryo temps are 12.4/61.7 ºk |
| ANS | anolla@naic.edu | 12/11/2000 | Receiver cal box taken down for a check out . Carl Hailes complain that there is a 45 deg phase shift between Cal on channels, so Lisa is checking it , |
| ANS | anolla@naic.edu | 12/13/2000 | Receiver cal box was reinstalled , system has to be recalibrated. |
| ANS | anolla@naic.edu | 12/19/2000 | Polarization check performed by WG & EC .Chan left is left and right is right. |
| ANS | anolla@naic.edu | 12/27/2000 | CB cryo hooked to comp 008 .Was on comp 010. |
| ANS | anolla@naic.edu | 12/29/2000 | The cryo was wrongly tie to comp 012 , it was suppose to go to comp 008 , the same comp used by 430 mhz.Was hooked back to comp 010. |
| ANS | anolla@naic.edu | 1/18/2001 | The cryo comp 010 was replaced with 012, now is running with the 430 MHz Dewar.It was running with the NLB & NSB. |
| ANS | anolla@naic.edu | 2/19/2001 | The cryo compressor was changed, it was 012 and was removed to 009, and it is in parallel with the 430. |
| ANS | anolla@naic.edu | 7/9/2001 | The post amp chassis was taken down in order to check the noise diodes. |
| ANS | anolla@naic.edu | 7/10/2001 | Post amp chassis box was installed back because it was going to be used tonight by Tapasi Goshi.No measurements were taken on it. |
| ANS | anolla@naic.edu | 7/16/2001 | Post amp chassis box was taken down againg in order to check its cal noise diodes on it. |
| ANS | anolla@naic.edu | 7/30/2001 | Cryo system turned off in order to replace contaminated crosshead. |
| ANS | anolla@naic.edu | 8/1/2001 | Replaced crosshead on Dewar , it was ED 015 , now is ED 013. The 16º stage takes a much longer time to cool down due to the mass on its stage (ant construction) , you can have a temp of 45 ºk on the 70 º stage after 4 hours , but at 16 º can be 200º.WATCH OUT FOR THESE .Also the supply cryo line (MSF 005) was replaced with a serviced one ( MSF 004). |
| ANS | anolla@naic.edu | 8/3/2001 | C-band post amp modifications: ------------------------------ 1) The channel B cal noise diode output was found to vary with the TTL signal level and Channel A diode's initial turn ON time was found to be about 6 to 8 seconds. Pending repairs at Micronetics factory, an interface circuit with a voltage regulator (LM 317LZ) has been built and incorporated. Now, the TTL signal turns the 5V-regulated output ON and OFF, ensuring the stability of diode B noise output. The turn-on time problem with diode A remains. Both these diodes will be sent for repair after the VSOP runs in August. 2) The heat sinking of the post amp was insufficient. It was improved by adding Al blocks with fins and properly fixing with heat sink compound. |
| ANS | anolla@naic.edu | 8/8/2001 | The ED 009 cryo comp was taken down for service, so ED 011 was hooked to the system. |
| ANS | anolla@naic.edu | 8/13/2001 | The ED 011 cryo comp removed from the system in order to hook up it's proper one to it, these is comp ED 012. Also we suspect that comp ED 011 is leaking. |
| ANS | anolla@naic.edu | 11/9/2001 | The heliax antennas to measure polarization cover from 4.5 to 5.5 Ghz , so cf is 5 Ghz.(L Wray measured them). |
| ANS | anolla@naic.edu | 11/26/2001 | System was warmed due to a power dip from yesterday. JR & IC went up to restarted. |
| ANS | anolla@naic.edu | 1/9/2002 | System was warmed up in order to replace its crosshead due to contamination, it was cycling. Crosshead was ED 013 , now is ED 019. |
| ANS | anolla@naic.edu | 1/24/2002 | There is an slope in the bandpass , LW working on it. |
| ANS | anolla@naic.edu | 4/17/2002 | System at room temperature , cryocomp quit (012). |
| ANS | anolla@naic.edu | 4/24/2002 | System was cooled down , cryocomp is now ED 007. Also there is a problem with the Tsys on chann A ,it has a Tsys of about 50 ºk instead 32 ºk , chann B is ok. |
| ans | anolla@naic.edu | Tuesday, August 13, 2002 15:13:48 | Post amp box down during the dual beam run to work on it. |
| LSW | lwray@naic.edu | Friday, August 16, 2002 16:09:10 | Post amp box still down, the receiver is not useable without it. |
| LSW | lwray@naic.edu | Friday, August 23, 2002 16:41:27 | Post amp chassis was put back on the telescope today. There were some wiring problems with the noise diode regulation circuit, but these have been fixed. The receiver is back in working condition. |
| ans | anolla@naic.edu | Wednesday, August 28, 2002 09:49:26 | Focal point of the receiver readjusted , new shims on Dewar. They are 1.08".PP checking its performance at the new focal point. |
| ans | anolla@naic.edu | Monday, September 9, 2002 11:52:09 | The CB shutter was not workink due to IC HSB shutter driver had something wrong with it and both TTL shutters driving signals run in parallel.HSB removes and everything worked ok. |
| ans | anolla@naic.edu | Wednesday, September 25, 2002 11:48:08 | Cryocomp down due to power dip. Dewar warmed up , been cooled. |
| lsw | lwray@naic.edu | Wednesday, October 16, 2002 11:40:49 | Found HEMT LED switch for Ch A was off. This increased the Tsys from 33 to 50K. It has been switched back on. |
| lsw | lwray@naic.edu | Saturday, November 2, 2002 11:40:22 | The kapton cover over the horn was removed on Wednesday October 30. In its place some Flouroglas fabric (permeable to radio waves, not to water) was put on, for testing. |
| LSW | lwray@naic.edu | Friday, November 22, 2002 17:43:25 | Nov 22: added a SMA female-SMAfemale and a SMA male-SMAmale connector to the output of Ch B's postamp, to put in a small phase delay as needed by the VLBI people. |
| ans | anolla@naic.edu | Wednesday, February 26, 2003 11:25:45 | CB post amp chassis down in order to replace the cal diodes. |
| lsw | lwray@naic.edu | Monday, March 3, 2003 16:28:37 | installed post amp box for pointing tests. old noise diodes still in. Changed attenuators after post amp from: 0/0 dB (A/B) to 3/2 dB, rebalancing levels after upstairs RF switch change. |
| lsw | lwray@naic.edu | Monday, April 14, 2003 16:35:08 | removed post amp chassis in order to install new diodes. |
| ans | anolla@naic.edu | Tuesday, April 29, 2003 08:43:16 | Chassis with new cal diodes back on 4/24/2003 . System was calibrated on 4/25/2003. |
| ans | anolla@naic.edu | Tuesday, May 6, 2003 13:01:16 | There was a ripple on chann B due to a loose sma connector in the cal diodes area. Ganesh and Lisa found it. |
| ans | anolla@naic.edu | Thursday, May 8, 2003 11:42:04 | For some reason the calibration was not working , we suspect of an intermittant TTL drive cable. Because it started working after we made several test. |
| ans | anolla@naic.edu | Friday, May 16, 2003 13:22:02 | P.P. calibrated the system this morning. |
| ans | anolla@naic.edu | Wednesday, January 7, 2004 15:05:19 | The cryocomp ED 007 was replaced by the ED011 due to an oil leak on it. |
| ans | anolla@naic.edu | Wednesday, January 14, 2004 13:07:11 | Cryocomp swap again due to a failure of cryocomp ED011.It was replaced by an ALFA one on 1/8/2004. But the they after it was found that the ALFA cryocomp was contaminated making both attached to it getting stock (430 & CB ). Then CB cryopump was purged an attached again to the Alfa cryocomp. |
| ans | anolla@naic.edu | Tuesday, January 20, 2004 16:31:17 | The cryopump ED019 was replaced by ED015 . It was contaminated by the ALFA cryocomp. |
| ans | anolla@naic.edu | Wednesday, January 21, 2004 16:14:56 | System back to operation. Was cooled down. |
| ans | anolla@naic.edu | Tuesday, February 3, 2004 14:35:42 | System cryo temp is unstable , for some reason its performance quit.The crosshead was recently swap. |
| ans | anolla@naic.edu | Tuesday, March 30, 2004 16:15:00 | There it was a short circuit at the rotary floor. For some reason also the main UPS (1400 VA) shorted out due to a shor at the remote sw for the meters inside cabinet #1. The remote sw was by passed. |
| ans | anolla@naic.edu | Monday, April 12, 2004 14:59:30 | There is not shuter due to burned out air compressor. |
| ans | anolla@naic.edu | Tuesday, April 13, 2004 15:51:46 | Yesterday we found that the air compressor for the shutter was burned out. So today we replaced it with a new one. Shutters are working properly. |
| lsw | lwray@naic.edu | Thursday, June 10, 2004 16:27:40 | Monday May 31: Power failure in dome for four hours caused C Band to warm up. When it cooled back down, Ch A's Tsys read 12K higher than before (used to be 32K/32K, now 44K/32K). |
| lsw | lwray@naic.edu | Thursday, June 10, 2004 16:28:34 | Troubleshooting Tsys problem. Possibly a bad connector at input of ChA postamp box. Now Tsys is 38K/32K. Will bring down postamp box next week (dual beam) to investigate. |
| lsw | lwray@naic.edu | Tuesday, June 15, 2004 08:22:58 | June 14: Took down the postamp, biasbox, RF cables to dewar and cal cables to dewar, and interconnect cable between bias and postamp box. Will look for high Tsys problem. |
| lsw | lwray@naic.edu | Monday, June 21, 2004 08:38:08 | June 18: Replaced postamp and bias chassis. The TTL cal cable from the IFLO cabinet to the postamp chassis was bad (weak connection at the postamp chassis end). Replaced with a semi-flex SMA cable. |
| lsw | lwray@naic.edu | Tuesday, June 22, 2004 13:56:45 | Troubleshooting downstairs: determined that the system sensitivity in Ch A is not higher than in Ch B, and that the cal value is not as high as we expect. For all cal types this is true. Therefore, problem points to losses in cal cable going to dewar. |
| lsw | lwray@naic.edu | Wednesday, June 23, 2004 16:25:54 | Performed many tests to figure out the Tsys problem (A 15K higher than B). 1. exchanged cal cables with lab cables. 2. put back original cal cables, then exchanged the RF cables between the dewar and postamp with lab cables. 3. put back original RF cables, then swapped the RF at the input of the postamp and also the output of the postamp. None of these tests showed any change in the tsys. |
| ans | anolla@naic.edu | Friday, July 2, 2004 11:33:35 | System down due to power shut down (main power line shorted at the rotary joint). |
| ans | anolla@naic.edu | Saturday, July 3, 2004 16:31:02 | System been cooled , will be ready for tonight. |
| ans | anolla@naic.edu | Wednesday, August 25, 2004 11:45:22 | The 430 & CB cryocopmp replaced. It was ED 007 ,now is ED 012. The ED 007 down for prev. maint. & modifications. |
| ans | anolla@naic.edu | Wednesday, September 22, 2004 14:40:22 | Cal cables were replaced , channel A was broken at the cal diode out. They are 21" long , also are phase match (6 deg at 5 ghz). |
| W Genter | wgenter@naic.edu | Friday, October 1, 2004 11:40:56 | C-Band receiver will be out of service from the evening of October 1 to October 8, 2004. This service is to repair a shorted amplifier LED. |
| ans | anolla@naic.edu | Monday, October 11, 2004 12:36:46 | System been cooled down.Exiter diode short fixed by BG. |
| ans | anolla@naic.edu | Tuesday, October 12, 2004 13:12:22 | System cycling in the 16 deg stage. Suspect of the 16 deg seal. |
| W. Genter | wgenter@naic.edu | Sunday, October 31, 2004 10:44:36 | This receiver is scheduled for a refrigerator change the week of 11/1/04. The refrigerator was last changed on 10/11/04. The Dewar temperature has remained at 20+k since cooled down on October 12, 2004. |
| ans | anolla@naic.edu | Monday, November 1, 2004 11:37:34 | System warmed up in order to replace crosshead. |
| ans | anolla@naic.edu | Monday, November 8, 2004 13:00:15 | The cryohead was replaced on 11/1/2004 , it was cooled down . Now 16ºstage is ok.Today the polarization box was added to the system , but still need the control bit to swap between linear and circular.Set at linear. |
| ans | anolla@naic.edu | Tuesday, November 9, 2004 10:58:24 | System down in order to check the post & pol box phase shift. |
| ans | anolla@naic.edu | Monday, November 15, 2004 13:04:23 | System back to normal.Tsys is chan A 33.2 ºk and B 34.7 ºk.It was at lab for phase measurments. |
| ans | anolla@naic.edu | Tuesday, November 30, 2004 14:30:28 | The calibration system was not working properly in all the receivers at the Dome . It was due that the post amp chassis for the CBH and XB were off. These was loading the other recvrs calibrators. |
| ans | anolla@naic.edu | Tuesday, November 30, 2004 14:35:27 | The recvr channels were check for isolation with the hex antennas at the bowl there were a 17 db difference between channels. Was at the Fo of 4.95 Ghz. |
| ans | anolla@naic.edu | Wednesday, January 19, 2005 13:19:14 | The noise injection board was replaced with the modified one to avoid oscillations. The one at the SBL was causing an rfi at 60 Mhz. |
| lsw | lwray@naic.edu | Thursday, January 27, 2005 12:45:54 | Jan 20: brought up new Polarization box but did not put into system yet. Jan 27: testing box with receiver. The box is not in the system yet. Need to make a control cable. CB is native linear, this box allows for circular pol. |
| ans | anolla@naic.edu | Monday, March 21, 2005 15:22:49 | Cryocomp replaced , it had a knocking sound.It was ED 012 , now is ED 007 |
| ans | anolla@naic.edu | Monday, April 18, 2005 15:29:57 | Receiver down for modifications since last week. |
| ans | anolla@naic.edu | Wednesday, May 25, 2005 13:12:51 | System back to service after replacing the rf amps at the Dewar with the indium phosphite ones (2 stages). Been cooled. |
| ans | anolla@naic.edu | Thursday, May 26, 2005 11:04:01 | System cooled & operational. |
| ans | anolla@naic.edu | Thursday, June 30, 2005 13:10:05 | The polarization box was installed in the receiver. Phil rechecked its command function and is ok. |
| W. Genter | wgenter@naic.edu | Friday, July 22, 2005 15:34:08 | Polorization check for VLBI run. |
| ans | anolla@naic.edu | Friday, August 26, 2005 13:06:58 | Due to power failure on 8/25/2005 system warmed up.Been cooled. |
| ans | anolla@naic.edu | Tuesday, August 30, 2005 15:59:01 | System back to normal. |
| ans | anolla@naic.edu | Wednesday, August 31, 2005 16:08:09 | Shutter was not working due that air compressor was bad. Replace it. |
| ans | anolla@naic.edu | Tuesday, September 13, 2005 10:12:23 | Shutter plate cover fall out after the dual beam run.Need locktite on the holding screw. |
| ans | anolla@naic.edu | Friday, October 28, 2005 14:16:10 | The system was warmed out in order to replace its crosshead. |
| ans | anolla@naic.edu | Monday, October 31, 2005 14:54:02 | Crosshead replaced it was ED 005,now is ED 014. |
| ans | anolla@naic.edu | Tuesday, November 1, 2005 09:55:09 | System cool , 16º stage is reading 14ºk. |
| W. Genter | wgenter@naic.edu | Wednesday, December 14, 2005 08:35:19 | Reported drop-out in both channels during observations. Checked 10GHz converter LO and Power Supplies. All cables stable. Connectors tight. |
| ans | anolla@naic.edu | Friday, January 27, 2006 14:58:47 | System was calibrated for Chris & Tapasi. |
| ans | anolla@naic.edu | Tuesday, May 9, 2006 14:35:31 | Cryo comp replaced , it was ED 007 , now is ED 015. |
| ans | anolla@naic.edu | Tuesday, May 16, 2006 11:35:38 | CBL pol box removed for measurments until further notice. |
| ans | anolla@naic.edu | Monday, June 12, 2006 14:33:15 | Polarization check perfomed today (Carlitos in charge). Polarization box still downstairs |
| ans | anolla@naic.edu | Monday, June 12, 2006 14:36:45 | Forgot to mention that the polarization check out results were the same as before. |
| ans | anolla@naic.edu | Thursday, July 6, 2006 12:51:09 | System calibrated today by Felipe. |
| ans | anolla@naic.edu | Thursday, July 6, 2006 12:52:02 | System was calibrated today by Felipe. |
| ans | anolla@naic.edu | Tuesday, January 23, 2007 11:48:08 | Polarization sw on it.Polarization can be adjusted from outside the chassis now. |
| ans | anolla@naic.edu | Monday, January 29, 2007 11:58:06 | Ganesh found that the gain in channel A is 3 db higher than B. Is affecting the pol test being performed on system. |
| ans | anolla@naic.edu | Monday, March 19, 2007 11:52:39 | System warmed up on 3/17/2007.BG turn off the crosshead that day. |
| ans | anolla@naic.edu | Wednesday, March 21, 2007 16:24:56 | After replacing crosshead , system being cooled. Cryohead was ED 014 , now is ED 025. |
| ans | anolla@naic.edu | Thursday, March 22, 2007 11:15:12 | System back to normal.Dewar valve closed but vacuum pump still on , being cleaned. |
| ans | anolla@naic.edu | Tuesday, April 24, 2007 10:41:36 | System down due to painting project. |
| CRV | Thursday, January 3, 2008 09:41:08 | Vacuum pump connected to the dewar and pumping on Dic.11th,2007 | |
| CRV | Thursday, January 3, 2008 09:42:14 | Dewar cooldown Started on Dic.11th,2007 afternoon. | |
| CRV | Thursday, January 3, 2008 09:43:03 | Dewar was cold by Dic.12th,2007 | |
| crv | Tuesday, January 29, 2008 16:53:34 | The system warmed down during this weekend 430mhz dual beam run. The compressor braeker opened during thge power dips. | |
| crv | Tuesday, January 29, 2008 16:56:53 | The system was vac. and cooled 1/29/08 |
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