| date |
1mm tests |
| LAB TESTS, 20 Feb 2007 dewar10, operating at 74 /15 / 3.2 / 3.5 / 3.4 K photos maintenance history stage3 displacer photos |
31-042-02 (NRAO junction) with WBA13 amp 104D photos of test junction in block two 0.2" diam bonded disk magnets on simple galv steel pole pieces IV curve Trcvr DSB bandpass.220GHz bandpass.240GHz bandpass.260GHz |
| LAB TESTS, 23 Feb 2007 dewar10 |
31-042-02 (NRAO junction) with WBA13 amp 104D replaced Teflon IR filter with foam IR filter replaced 0.00024" thick beamsplitter with 0.0005" thick beamsplitter Trcvr DSB 246 GHz scans showing Josephson troubles |
| LAB TESTS, 21 Mar 2007 dewar10 |
31-042-02 (NRAO junction) with WBA13 amp 104D Zotefoam IR filter, 0.0005" thick beamsplitter, two 0.4" diam magnets IV curve Trcvr DSB 246 GHz scans for comparison with 23 Feb scans |
| LAB TESTS, 28 June 2007 dewar10, operating at 80 / 15 / 3.8 / 3.9 / 3.9 K |
31-042-02 (NRAO junction) with WBA13 amp 104D Zotefoam IR filter, 0.0005"/0.00025" thick beamsplitter, copper solenoid for tunable magnetic field plot of supercurrent at V=0 vs solenoid current, showing hysteresis IV curve Trcvr DSB 246 GHz scans with magnet current 20 mA (nulls supercurrent), 10 mA (field too low), 35 mA (field slightly too high) bandpass at 220GHz, 240GHz, 260GHz LO power from tripler, measured with Erickson power meter |
| LAB TESTS, 16 July 2007 dewar10, operating at 80 / 15 / 3.9 / 4.0 / 4.0 K |
31-042-03 (NRAO junction) with WBA13 amp 104D Zotefoam IR filter, 0.001" thick beamsplitter, copper solenoid for tunable magnetic field NOTE: Greg installed 2 wirebonds across the BOTTOM of the quartz microstrip to help hold device tightly in the channel; these may be screwing up its performance IV curve Trcvr DSB 220 GHz scan with 45 mA solenoid current (approximately nulls Josephson steps) 250 GHz scan with 45 mA solenoid current bandpass.220GHz bandpass.260GHz |
| LAB TESTS, 18 July 2007 dewar10, operating at 75 / 14.8 / 3.3 / 3.6 / 3.6 K ( 75 / 14.8 / 3.2 / 3.4 / 3.4 with no current to solenoid ) |
31-042-03 (NRAO junction) with WBA13 amp 104D Zotefoam IR filter, 0.0005" thick beamsplitter, copper solenoid for tunable magnetic field since last test, Greg removed the 2 wirebonds across the bottom of the device; the only other change is to go to the 0.0005" thick beamsplitter IV curve Trcvr DSB 220 GHz scan with 45 mA solenoid current (approximately nulls Josephson steps) 250 GHz scan with 45 mA solenoid current bandpass.220GHz bandpass.260GHz |
| LAB TESTS, 25 July 2007 dewar10, operating at 77 / 14.9 / 3.5 / 3.8 / 3.7 K ( 77 / 14.9 / 3.2 / 3.4 / 3.4 with no current to solenoid ) |
31-042-05 (NRAO junction) (photos)
with WBA13 amp 104D Zotefoam IR filter, 0.0005" thick beamsplitter, hybrid solenoid for tunable magnetic field; (hybrid solenoid is steel mandrel with hole for small permanent magnet in center, wound with 32 gauge magnet wire) IV curve showing weird behavior Trcvr DSB 220 GHz scan 250 GHz scan 250 GHz scan at varying solenoid currents bandpass.220GHz bandpass.260GHz |
| LAB TESTS, 02 Aug 2007 dewar10 |
31-042-03 (NRAO junction)
with WBA13 amp 104D Zotefoam IR filter, 0.0005" thick beamsplitter retesting with new hybrid solenoid (two 0.16" diam permanent magnets in core, approx 900 turns of 34 gauge copper wire on outside) goal is to see if noise temp is better than on 18jul07 now that we have carefully tightened SMA connectors in dewar; also, to test new solenoid results: permanent magnets may be too strong, solenoid current has little effect on IV curve 250 GHz scan shows that tuning a bit tricky if we only use permanent magnets rcvr temp 52 K at 220 GHz, 53 K at 230 GHz, 83 K at 250 GHz |
| LAB TESTS, 14 Aug 2007 dewar10 |
31-042-02 (NRAO junction)
with WBA13 amp 104D Zotefoam IR filter, 0.0005" thick beamsplitter retesting with hybrid solenoid (one 0.16" diam, one 0.08" diam permanent magnets in core) goal is to recheck noise temp of the original good mixer after a long string of disappointing results with other mixers tests through Styrofoam dewar gave ~80K, so we remounted the dewar UPSIDE DOWN to look down into a pool of LN2; now tsys measurements seem much more consistent, though still not as good as on 20Feb solenoid current has little effect on IV curve 246 GHz scan for comparison with scans taken earlier |
| LAB TESTS, 22 Aug 2007 dewar10 photos |
OMT 3 (Protofab, not gold plated), Zotefoam IR filter, 0.0005" thick beamsplitter band 'B': mixer 31-042-02 , amp 104D, sensor #5 connected to thermal 'hotdog', plastic solenoid, 318 ohms resistance at room temp, connected to sensor7 slot band 'D': mixer 31-042-03 , amp 123D, sensor #4, steel solenoid, 492 ohms resistance at room temp, connected to sensor6 slot - mixer 'B' is an open circuit for this test - mixer 'D' supercurrent could be tuned out with 36 mA through solenoid - IV curve - mixer 'D' 250 GHz scan - mixer 'D' tsys through OMT, compared with previous data |
| LAB TESTS, 24 Aug 2007 dewar10 photos of test setup showing Alberto's bias board installed; (but test results shown here were made through old control box) |
same setup as 22 Aug, except that Greg opened up both mixers and installed
slivers of 0.7 mil mylar on top of the quartz, just in the ground pad area, to make sure that devices
are pressed into the slot OMT 3 (Protofab, not gold plated), Zotefoam IR filter, 0.0005" thick beamsplitter band 'B': mixer 31-042-02 , amp 104D, sensor #5 connected to thermal 'hotdog', plastic solenoid, 318 ohms resistance at room temp, connected to sensor7 slot band 'D': mixer 31-042-03 , amp 123D, sensor #4, steel solenoid, 492 ohms resistance at room temp, connected to sensor6 slot - attenuator tuned by hand to give 125 uA bias on mixer B, 105 uA bias on mixer D, at 220 GHz - mixer 'B' solenoid current has little effect on IV curve - mixer 'B' 220 GHz scan showing that we can still measure tsys at 220 GHz - mixer 'B' tsys at 220 GHz through OMT, compared with previous measurements; no change if mixer D is biased at 0 mV or at 8 mV - no tests of mixer 'D' |
| LAB TESTS, 04 Sep 2007 dewar10 photos of dewar |
changes since last test: removed mixer 31-042-03, WBA13 #123D,
492 ohm solenoid, from OMT; port left open band 'B': mixer 31-011-4 , amp 10B, modified to include integral bias tee for the mixer; SMA M-M elbow between mixer and amp; sensor 4 on double hotdog photo of inductor attached to WBA13 input line S11 before, after adding inductor (at room temp) S21 before, after adding inductor (at room temp) results: amplifier appears to be oscillating; mixer bias current changes from 25 uA to 100 uA when amp begins to draw current band 'D': mixer 31-042-02 , amp 104D, sensor #5, new solenoid with Delrin mandrel, steel core, 430 ohms at room temp mounted on OMT 3 (Protofab, not gold plated), other port left open; Zotefoam IR filter, 0.0005" beamsplitter - IV curve - 40 mA solenoid current nulls supercurrents - tsys consistent with 14Aug results |
| LAB TESTS, 11 Sep 2007 dewar10 |
band D: mixer block 31-042-05 ,
NRAO junction A1 (UVa-N10-06-L1391-1-KG-C12,L56-1; 89 ohms) mixer mounted on 1 port of OMT 3 (Protofab, not gold plated), other port left open; 492 ohm solenoid? - IV curve shows that only 1.7 mA solenoid current nulls the Josephson steps! - tsys - poor below 230 GHz; LObias = 85 uA - scans at 230 GHz, 240 GHz, 260 GHz - bandpass.260GHz |
| LAB TESTS, 13/14 Sep 2007 dewar10 photos of dewar |
band B: mixer 31-011-4 , amp 86D, modified to include integral
bias tee for the mixer; input connector changed to SS male SMA so it mates directly to mixer block thermal 'hotdog', plastic solenoid, 318 ohms resistance at room temp, connected to sensor7 slot - mixer B IV curve - mixer B tsys - mixer B 75 GHz, 90 GHz, 113 GHz bandpass band D: OMT 3 (Protofab, not gold plated), Zotefoam IR filter, 0.0005" thick beamsplitter mixer 31-042-01 (NRAO device H1 = UVa-N10-07-L1380-0205-2-EM-C12,L56-3 111 ohms); other OMT port empty WBA13 amp 104D Vg=2.22 Id=26 mA, sensor #5, solenoid with Delrin mandrel, steel core, 430 ohms at room temp; sensor 5 - mixer D IV curve - 10 mA solenoid current nulls steps - mixer D 215 GHz, 220 GHz, 240 GHz, 260 GHz scans - mixer D tsys - mixer D 220 GHz, 240 GHz, 260 GHz passband data |
| LAB TESTS, 15 Sep 2007 dewar10 |
band B: no test band D: mixer 31-012-08 (BIMA device, removed from mixer 31-015-1) with permanent magnet, WBA13 amp 86D mixer attached with long bond wire to SMA pin - no microstrip to heatsink SMA center pin to 4 K IV curve compared with 31-015-1 no valid noise temperature tests |
| LAB TESTS, 28 Sep 2007 dewar10 |
band B: no test band D: mixer 31-042-04 (NRAO device D1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-1, 91 ohms), WBA13 amp 86D installed on OMT 3 (Protofab, not gold plated), 2nd port empty; Zotefoam IR filter, 0.0005" thick beamsplitter - capacitor, coil removed from bias tee board inside mixer block; mixer biased from WBA13 bias tee - IV curve shows weird hysteresis near Vgap when WBA13 amp is on - no valid noise temperature tests |
| LAB TESTS, 03 Oct 2007 dewar10 temperatures with no solenoid current: 74 / 14.15 / 3.2 / amp 14.5 / mixer 3.66 temperatures with 60 mA solenoid current: 74 / 14.3 / 3.73 / amp 15.3 / mixer 4.75 |
band B: no mixer band D: mixer 31-042-04 (NRAO device D1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-1, 91 ohms), WBA13 amp 86D installed on OMT 3 (Protofab, not gold plated), 2nd port empty; Zotefoam IR filter, 0.0005" thick beamsplitter - change from 01 Oct: mixer is biased through the bias tee in the mixer block, not the WBA13 - IV curve - 10 mA solenoid current nulls steps, 60 mA softens curve - 220 GHz scan at 10 mA solenoid current - oscillations at harmonics of 580 MHz break out near center of gain peak, independent of amplifier drain current - 220, 240, 260 GHz scans at 60 mA solenoid current - no problems - bandpass is flatter with higher LObias, independent of magnetic field 220, 240, 260 GHz passband data - tsys - 220-230 data still screwed up by oscillations, apparently, although we used 60 mA solenoid current CONCLUSIONS: (1) softer IV curve seems to avoid low freq oscillations; (2) passband shapes independent of solenoid current, but flatter for LObias > 90 uA |
| LAB TESTS, 05 Oct 2007 dewar10 temperatures 72 / 14 / 3.1 / 3.6 (on 4K stab plate) / 3.6 (on mixer) |
band B: no mixer band D: mixer 31-042-04 (NRAO device D1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-1, 91 ohms), two 0.158" diam permanent magnets on pole pieces, WBA13 amp 104D - changes from 03 Oct: (1) mixer is connected to horn through adapters, not OMT; (2) permanent magnets; (3) using amp 104 D - IV curve - permanent magnets give softer IV curve than 60 mA through solenoid - 220, 260 GHz scans - no problems; some Josephson twitches at higher LO bias values - 220, 240, 260 GHz passband data - 220 and 240 GHz data comparable with that from 03oct, despite change of amp - bandpassAll.pdf comparison of passbands at 3 freqs - wideband trcvr approx 43 K at 220 GHz, approx 50 K at 260 GHz; calwheel broke before we could do full test CONCLUSIONS: (1) noise temps and passbands OK despite rounded IV curve from permanent magnet (2) need LObias of > 90 uA for flattest passband; (3) noise temps slightly better than 03 Oct when we used OMT - uh oh! |
| LAB TESTS, 09 Oct 2007 dewar10 |
band B: no mixer band D: mixer 31-012-8 (BIMA junctions taken from 31-015-1, remounted with quartz microstrip for heatsink, graph paper in bottom of slot to keep it from tilting), permanent magnets on fancy pole pieces, WBA13 amp 86D with integral bias tee - no tests: blown junction (mixer current is 500 uA at 1 mV bias, but drops to 58 uA when temp climbs to 9 K) |
| LAB TESTS, 10 Oct 2007 dewar10 |
band B: no mixer band D: mixer 31-012-8 (since yesterday's test, Greg removed dead junction, installed another device from wafer 1; as before, this uses quartz microstrip for heatsink); WBA13 amp 86D with integral bias tee - no tests: IV curve very poor; turning on amp makes it a straight line - IV curve was so strange that we put aluminum foil over dewar window to make sure room temp radiation wasn't smearing out the curve, but there was no change - we also considered the possibility of large heat load from amp; however, driving 2nd stage temp to 30 K with heater made no difference to mixer IV curve |
| LAB TESTS, 12 Oct 2007 dewar10 |
band B: mixer 31-011-8 with previously untested BIMA device from batch CO100-5; 22 uA bias at 1 mV;
WBA13 amp 86D with integral bias tee band D: mixer 31-042-06 (NRAO device B1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-2, 91 ohms), mounted with no plastic under mixer; two permanent magnets in series, one 0.158" diam and the other 0.078" diam; WBA13 amp 104D band B: mixer is blown, draws 500 uA when cold; no tests band D: IV curve looks great, but Trcvr is bad, passband is bad; suspect cracked chip cap in mixer bias tee - IV curve looks good; no change when amp is turned on - 220, 240, 260 GHz scans; marred by amplifier oscillations at 220 GHz - Y-factors are terrible; lowest Trcvr is 335 K |
| LAB TESTS, 16 Oct 2007 dewar10 |
band B: mixer 31-011-8 with previously untested BIMA device from batch CO100-2;
WBA13 amp 86D with integral bias tee - IV curve has weird loop above gap, otherwise OK - 90, 100, 110 GHz scans show that 2nd peak is best - 80, 90, 100, 110 bandpass data; ripples, but continues to perform to 7.3 GHz - tsys data taken with full passband - band D: mixer 31-042-06 (NRAO device B1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-2, 91 ohms); since last test: Greg removed excess EpoTek epoxy that shorted SMA pin; SMA connector mounted to block with proper 3-48 screws, rather than 2-56; Mylar strip installed under device? two permanent magnets in series, one 0.158" diam and the other 0.078" diam; WBA13 amp 104D - IV curve looks good; no change when amp is turned on - 220, 240, 260 GHz scans; marred by low freq (350 MHz and harmonics) oscillations at 220 GHz - 220, 240, 260 GHz passbands are very ripply - tsys data taken with full passband |
| LAB TESTS, 19 Oct 2007 dewar10 |
band B: mixer 31-011-8 changes since 16oct07: external bias tee, HEMT amp #7 - IV curve is unchanged (but doesn't show extra loop) - 90, 100 GHz scans are similar to those with WBA13 - 90, 100, 110 bandpasses compared with WBA13 data - tsys data taken with old passband filter band D: mixer 31-042-06 (NRAO device B1 = UVa-N10-06-L1391-0504-1-KG-C12,L56-2, 91 ohms); changes from 16oct07: two 0.158" diam permanent magnets instead of one 0.078", one 0.158" WBA13 amp 104D - IV curve unchanged since 16oct07 - 220 GHz scan unchanged since 16oct07, still is marred by oscillations at multiples of ~350 MHz - no other tests |
| LAB TESTS, 01 Nov 2007 dewar10 |
band B: mixer 31-042-02, pole pieces with permanent magnets, no amp changes since xx: Greg removed dead junction, installed device from pogo strip 1395; I infer that tuning is C12,L56; 16 uA at 1 mV bias - IV curve looks bad band D: mixer 31-042-03 , WBA13 amp 152D, good pole pieces with permanent magnets mixer mounted on miniflange adapter to feed horn changes from xx: replaced Zotefoam 50 K window with original Teflon window - no tests: IV curve OK, but amp drain current is 38 mA for 0.4 mV bias; amp appears to have only 10 dB gain; it turns out that amp 152D is unusual, requires 2 different gate voltages |
| LAB TESTS, 05 Nov 2007 dewar10 |
band B: mixer 31-042-02 , no amp changes since 01nov07: removed magnets and pole pieces - IV curve looks bad band D: mixer 31-042-03 , WBA13 amp 159D, good pole pieces with one 0.158" diam and one 0.078" diam permanent magnets in series mixer mounted on miniflange adapter to feed horn changes from 01nov07: changed WBA13 amp, changed from two 0.158" diam magnets - IV curve looks fine - 220, 240, 260 GHz scans - tsys data taken with full passband, compared with 07nov07 data when mixer was mounted on OMT; standing wave pattern appears to change |
| LAB TESTS, 07 Nov 2007 dewar10 using gold-plated 2nd stage radiation shield operating at 72 / 14 / 3.2 / 3.4 / 3.8 K |
band B: mixer 31-042-02 , no amp changes since xxoct07: Greg removed previous junction, installed new device from pogo strip 1395; tuning is C14,L62; 17 uA current at 1 mV bias; no magnets - IV curve looks bad band D: mixer 31-042-03 mounted on OMT #3, WBA13 amp 159D, variable solenoid changes from 05oct07: removed miniflange adapter, which appeared to have burrs that might have created gap between adapter and mixer block, tunable solenoid replaces permanent magnets; ultrasonically cleaned horn and horn lens - IV curves vs solenoid current - shortscan.pdf - scan at 260 GHz vs solenoid current; shows how touchy the tuning can be - 220 GHz scan at 15 mA solenoid current - 260 GHz scans with 15 mA and 30 mA solenoid current - tsys data taken with full passband |
| LAB TESTS, 09 Nov 2007 dewar10 gold plated 1st and 2nd stage radiation shields |
OMT 3 (Protofab, not gold plated), Teflon IR filter, 0.0005" thick beamsplitter band B: mixer 31-042-04 with WBA13 amp 159D, permanent magnets, one 0.158" diam and one 0.079" diam in series, with crude pole pieces changes since 05oct07: today Greg removed the device, ultrasonically cleaned it (dislodging a scrap of indium), used wirebonder to tack down the existing grounding wires at several more places along the edges of the device, reinstalled in block with mylar spacer - IV curve with permanent magnets looks similar to curve on 03oct07 with 60 mA solenoid current - tsys; below 230 GHz huge spikes at 500 MHz and first few harmonics appear in the IF (independent of amplifier drain current); tsys measurements possible in this range only with 2 GHz HP filter between dewar and PAM; note: had to install 1 mil beamsplitter to make these measurements because OMT is rotated by 30 degrees instead of 45 degrees - 220, 240 GHz bandpasses - CONCLUSIONS: spikes in passband still a mystery; no particular improvement after remounting the device; avg noise temps with passband filter were < 40 K at times band D: mixer 31-042-03 with HEMT amp #7 (connected via 3" semiflex cable); variable solenoid changes since 06nov07: try narrowband amplifier - IV curve - tsys with Tap amplifier, old passband filter; big standing wave matches standing wave from 07nov - 220, 240, 260 GHz passbands not particularly flat, even with Tap amp - CONCLUSIONS: no big improvements from using Tap amplifier |
| LAB TESTS, 03 Dec 2007 dewar10 gold plated 1st and 2nd stage radiation shields |
Teflon IR filter, 0.001" thick beamsplitter band B: no mixer band D: mixer 31-042-02 with WBA13 #159D; variable solenoid; mounted to feed horn with adapter 31-048 changes since 06nov07: mixer block rebuilt; epotek epoxy used previously was found to be defective, so circuit board was pried out and soldered back with indium solder; dowel pin holes reamed out so block fit together easily; wirebonds on lid to press down on device; NRAO device UVa-N10-07-L1380-0205-2-EL-C12,L56-2 (108 ohms) - IV curve - tsys; 2 GHz HP filter needed between dewar and PAM below 230 GHz because of oscillations at 500 MHz and harmonics - 220, 240, 260 GHz scans - 220, 240, 260 GHz passbands - CONCLUSIONS: pretty decent results, marred only by low freq oscillations in the IF passband |
| LAB TESTS, 11 Dec 2007 (future) dewar10 gold plated 1st and 2nd stage radiation shields |
Teflon IR filter band B: no mixer band D: mixer 31-042-03 with WBA13 #159D; variable solenoid; connected to horn with adapter 31-048 changes: mixer rebuilt; circuit board pried out, epoxy scraped off, board soldered in with indium solder; we are now using 6.8 pf coupling capacitor on the bias tee, with 10 turn inductor - S11 with 12 pF coupling capacitor; S11 with 6.8 pF coupling capacitor - IV curve - tsys; 2 GHz HP filter needed between dewar and PAM below 230 GHz because of low freq oscillations - 220, 240, 260 GHz scans - 220, 240, 260 GHz passbands |
| LAB TESTS, xx Dec 2007 (future) dewar10 gold plated 1st and 2nd stage radiation shields |
Teflon IR filter band B: no mixer band D: mixer 31-042-01 with WBA13 #104D; variable solenoid; connected to horn with adapter 31-048 changes: mixer renovated; circuit board pried out, epoxy scraped off, board and quartz strip soldered in with indium solder; 33 pf coupling capacitor replaced with 6.8 pF; installed device G1 from the NRAO box - S11 with 12 pF coupling capacitor; S11 with 6.8 pF coupling capacitor |
| LAB TESTS, 21 Dec 2007 (future) dewar10 gold plated 1st and 2nd stage radiation shields running at 70 / 13.6 / 3.2 / 3.3 / 3.6 K |
band B: no mixer band D: mixer 31-042-05 with WBA13 #104D; variable solenoid; connected to horn with adapter 31-048 changes: mixer renovated; circuit board pried out, epoxy scraped off, board soldered in with indium solder; 33 pF coupling cap replaced by 6.8 pF; Dielectric Labs B28BH8FN01 bias filter networks installed on both VS+ and Vsense+ lines, between Hirose connector and 10K chip resistors; device G1 removed from block 31-042-01 and installed into this block; no wirebonds on the lid - IV curve; tsys (with 2 GHz HP filter); 220, 240, 260 GHz scans; 220, 240, 260 GHz passbands |
| LAB TESTS, 31 Dec 2007 dewar10 gold plated 1st and 2nd stage radiation shields running at 66 / 13.4 / 3.1 / 3.3 / 3.5 K |
band B: no mixer band D: mixer 31-042-05 with WBA13 #104D; bad pole pieces with permanent magnets; connected to horn with adapter 31-048 changes: mixer opened, 680 pF capacitor on bias tee removed; permanent magnet installed; otherwise no change since 21 Dec - IV curve; tsys (no 2 GHz HP filter needed); 220, 240, 260 GHz scans; 220, 240, 260 GHz passbands |
| LAB TESTS, 07 Jan 2008 dewar10 gold plated 1st and 2nd stage radiation shields running at 70 / 13.9 / 3.15 / 3.4 / 3.5 K |
band B: no mixer band D: mixer 31-012-8 with WBA13 #86D (annex bias tee); pole pieces with permanent magnets; connected to horn through Custom Microwave 'hockey puck' round-rect adapter changes: we tried to test this mixer on 10 Oct, with same WBA13 amp, but turning on the amp turned the IV curve to a straight line; bias tee circuit on WBA13 has since been upgraded by using gold plated annex, proper circuit board screwed down with 0-80 screw - IV curve is OK if we keep amp drain current below about 12 mA; above that, amplifier begins to oscillate at ~ 12 GHz, messing up the IV curve - tsys peaks at about 240 GHz - 220, 240, 260 GHz scans - 220, 240, 260 GHz passbands; 220 looks OK, but others are ripply |
| LAB TESTS, 09 Jan 2008 dewar10 gold plated 1st and 2nd stage radiation shields running at 68 / 13.5 / 3.2 / 3.9 / 3.7 |
band B: mixer HIA-091 , amp 86D with integrated bias tee - IV curve - tsys , measured with JCA amp on dewar output, 2 GHz HP filt between JCA amp and PAM - 77, 90, 100, 110 GHz scans - 90, 100, 110 GHz bandpass band D: mixer 31-042-05 with WBA13 #104D; nice pole pieces with one 0.078 and one 0.158 diam magnet; connected to horn P3136-3 through miniflange adapter 31-048 changes: basically same test as 31 Dec 2007 except pole pieces and magnets are different, and we are using old horn instead of new, to see if horn could be responsible for noise temp hump at 245 GHz - IV curve shows 'integral sign' behavior if amp is on br> - tsys; hump is still there, a bit worse - 220 GHz bandpass |
| LAB TESTS, 01 Feb 2008 dewar7 |
band B: empty band D: mixer 31-042-06 with WBA13 86D pogo strip device; bias tee in both mixer and amp - used the mixer one IV curve is a straight line (172 uA at 10 mV = 56 ohms, with 2 nominally 100-ohm resistors in parallel to gnd) - no tests |
| LAB TESTS, 04 Feb 2008 dewar7 |
band B: empty band D: mixer 31-042-06 with WBA13 ? changes since last time: Greg removed old device; installed another mixer with NRAO box of 10; weird IV curve with integral shape at gap WBA13 oscillates at 5 GHz if Idrain > 15 mA; all tests done with Vgate=2.1 V; noise temps 80-120 K, ripply passbands |
| LAB TESTS, 06 Feb 2008 dewar7 |
band B: empty band D: mixer 31-042-06 with WBA13 ? changes since last time: Greg removed old device; installed another mixer with NRAO box of 10; bad IV curve - looks like 2 junctions shorted out - no tests |
| LAB TESTS, 07 Feb 2008 dewar7 |
band B: empty band D: mixer 31-042-06 with WBA13 159D changes since last time: Greg removed old device; installed another mixer with tuning C12,L56 from pogo strip into mixer; device has extremely high resistance - barely a change in slope at 10.5 mV - no tests |
| LAB TESTS, 12 Feb 2008 dewar10 |
band B: HIA-091, WBA13 86D wideband noise temps as low as 33K band D: mixer 31-042-02 with WBA13 #104D low freq oscillations from 560 pF capacitor IV curve shows integral-shaped wiggle at 10 mV |
| LAB TESTS, 13 Feb 2008 dewar7 |
band B: empty band D: mixer 31-042-06 with WBA13 159D changes since last time: Greg removed C12,L56 device; installed another mixer with tuning C14,L56 from pogo strip into mixer; using Alessandro's miniflange-rect-round adapter device appears to be an open circuit - no tests |
| LAB TESTS, 14 Feb 2008 - last test before putting on C14 dewar10 non gold-plated 1st and 2nd stage radiation shields |
band B: mixer HIA-091 , amp 86D with integrated bias tee - IV curve - tsys - 90, 100, 110 GHz bandpass band D: mixer 31-042-02 with WBA13 #104D nice pole pieces with one 0.078 and one 0.158 diam magnet; connected to horn through miniflange adapter 31-048 - IV curve - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 19 Feb 2008 dewar7 gold-plated 1st and 2nd stage radiation shields |
band B: slot empty band D: mixer 31-042-03 with WBA13 #? pole pieces with one 0.078 and one 0.158 diam magnet?; connected to horn through delicate Custom Microwave miniflange adapter changes since last test on 11dec07: Greg opened mixer, installed 5 ohm resistor in series with the IF; unfortunately he left 560 pF cap in the bias tee, which causes low freq oscillations; also we are using permanent magnets rather than variable solenoid - IV curve, compared with 11dec07 curve - tsys, compared with 11dec07 - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 19 Mar 2008 dewar7 running at 66/16/3.2/3.7/3.7 K |
band D: 31-050-01 with WBA13 #147D (bias tee annex) SIS device from pogo strip 1380, tuning C12,L56; 16 uA at 1 mV hockey puck waveguide and mixer waveguide are offset .078" diam magnet, 0.4" long, in each hole B-field too strong, IV curve is rounded; best Y-factor ~ 1.5 |
| LAB TESTS, 20 Mar 2008 dewar7 running at 66/16/3.6/3.9/4.0 K |
band D: 31-050-01 with WBA13 #147D (bias tee annex) fragment of small magnet, each 0.1" long, in each hole unfortunately this is still too much B-field, IV curve is rounded and Tsys ~ 150 K |
| LAB TESTS, 24 Mar 2008 dewar7 |
band D: mixer 31-050-01 with WBA13 #147D (bias tee annex) solenoid to null supercurrent; about 25 mA does it Tsys ~ 75 K; passband ugly, no gain at 7 GHz - later traced to WBA13 |
| LAB TESTS, 02 Apr 2008 dewar4 running at 47/11/3.5/3.7/3.7 K |
band B: mixer HIA-185 with WBA13 #147D (bias tee annex) - something appears to be wrong with WBA13; Trcvr has big spike at 7 GHz; later found that amp had poor match with nominal gate voltage, wants much lower gate voltage - IV curve - tsys 100, 110 GHz bandpasses band D: mixer 31-015-1 with WBA13 #89D this uses junction taken out of block 31-015-2; no 560 pF capacitor on bias tee; at room temp, mixer bias of 1 mV gave 23 uA current, anomalously high l shorted junction - no tests |
| LAB TESTS, 03 Apr 2008 dewar4 |
band B: mixer HIA-185 with WBA13 #184D (James Lamb bias tee) - IV curve - tsys 100, 110 GHz bandpasses band D: mixer 31-015-2 with WBA13 #89D at room temp, bias was 22.5 uA at 1 mV shorted junction - no tests |
| LAB TESTS, 04 Apr 2008 - now on C15 dewar4 |
band B: mixer HIA-185 with WBA13 #155D (bias tee annex) - IV curve - tsys - 90, 100, 110 GHz bandpasses band D: mixer 31-015-1 with WBA13 #89D device newly installed by Greg from BIMA wafer 1; 1 mV -> 17 uA at room temp - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 16 Apr 2008 (now on C13) dewar11 |
band B: mixer HIA-180 with WBA13 #184D (James Lamb bias tee) - IV curve - tsys - 90, 100, 110 GHz bandpasses band D: mixer 31-015A-5 with WBA13 #22B - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 29 Apr 2008 dewar5 running at 56 / 13.5 / 3.1 / 3.4 / 3.2 K |
band B: mixer HIA-191 with WBA13 #172D (bias tee annex) - IV curve - tsys - 90, 100, 110 GHz bandpasses band D: mixer 31-012-6 with WBA13 #22B - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 02 May 2008 dewar7 running at 60 / 15 / 3.6 / 4.3 / 4.1 K 282828 |
band D: mixer 31-050-01 with WBA13 #169D SIS device is the first from Berkeley UVa wafer, tuning C12,L56 connected to horn through delicate Custom Microwave miniflange adapter solenoid to set magnetic field; about 50 mA needed to zero supercurrent, but tested at 25 mA 282828- IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 05 May 2008 dewar7 |
band D: 31-042-06 with WBA13 #179D; UVa B6 wafer, C12,L56 taken from 31-050-01 connected to horn through delicate Custom Microwave miniflange adapter good pole pieces, 1 small and 1 medium magnet - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 08 May 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-04 with WBA13 #179D; UVa B6 wafer, C14,L56 device; short bond wire good pole pieces with 1 med, 1 small permanent magnet - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses band D: 31-050-01 with WBA13 #169D; pogo mixer, sloppy pole pieces with solenoid - IV curve now bad; no further tests |
| LAB TESTS, 09 May 2008 dewar7 running at 57 / 17 / 3.7 / 3.9 / 4.0 K |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-06 with WBA13 #179D; UVa B6 wafer, C12,L56 device; .15" bond wire good pole pieces with 1 med, 1 small permanent magnet - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses band D: 31-042-04 with WBA13 #169D; UVa B6 wafer, C14,L56 device, .18" bond wire sloppy pole pieces with 2 medium permanent magnets - IV curve, compared with other devices - tsys - 220, 240, 260 GHz bandpasses |
| LAB TESTS, 15 May 2008 dewar 14 running at 53/14.6/3.5/3.6/3.6 |
band B: HIA-073 with WBA13 #204D band D: 31-015A-1 with WBA13 #105D |
| LAB TESTS, 28 May 2008 dewar7 running at 67-17-3.6-3.6-3.9 |
band D: 31-050-01 with WBA13 #169D; UVa B6 wafer, device H1, C12,L56 device;
long wirebond, makeshift capacitor one mixer mounted on OMT variable solenoid, 38 mA nulls supercurrents note: I photographed this device after it was taken out of mixer |
| LAB TESTS, 30 May 2008 dewar7 running at 58-16-3.8-3.9-4.1 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-03 with WBA13 #179D 2 medium magnets on good pole pieces - field too strong this device tested previously on 19feb08 band D: 31-050-01 with WBA13 #169D; pogo strip 1380 device, C14,L56 tuning long bond wire to makeshift capacitor; variable solenoid, 43 mA; 21.5 uA at 1 mV |
| LAB TESTS, 03 Jun 2008 dewar12 running at 58-16-3.8-3.9-4.1 |
band B: HIA-068 with WBA13 #159D Idrain is flaky - periodic 20 mV glitches in current monitor; consequently, IF power is flaky band D: 31-015-2W20 with WBA13 #3L device from wafer #1; bits of paper keep substrate from falling to bottom of slot used from Sep06 - May08 on telescope C11; previous lab test on 13Sep06 |
| LAB TESTS, 06 Jun 2008 dewar7 running at 58-16-3.8-3.9-4.1 |
same setup as 03 Jun, except band B amp switched to WBA13 #123D no tests done because WBA13 bias cable was bad |
| LAB TESTS, 09 Jun 2008 dewar12 |
band B: HIA-068 with WBA13 #123D; Idrain is stable - IV curve, and pumped IV curve - tsys - scans at 100 GHz - 90, 100, 1100 GHz bandpasses band D: 31-015-2W20 with WBA13 #3L test data are from 03jun08 cooldown - no need to repeat them today device from wafer #1; bits of paper keep substrate from falling to bottom of slot used from Sep06 - May08 on telescope C11; previous lab test on 13Sep06 |
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LAB TESTS, 10 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-01 with WBA13 #179D device H1 from C14 L62 box; single 0.8 mil x 50 mil bias lead; 19.5 uA @ 1mV bias 1 medium and 1 small magnet (device later transferred to slot A2 of 'SIS harvested' gelpak) band D: 31-050-01 with WBA13 #169D; solenoid pogo strip 1380 device, C14,L56 tuning removed from this mixer, put in slot A1 of "SIS Harvested" gelpak installed device F5 from C14 L62 box; double 0.8 x 100 mil gold bias leads; 21.3 uA @ 1 mV bias |
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LAB TESTS, 13 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-01 with UVa C14,L59 device; WBA13 #179D 1 medium and 1 small magnet results: 65K, passband flat above 4 GHz band D: 31-050-01 with UVa C14, L59 device; WBA13 #169D; solenoid 1 junction blown, must bias at 7 mV; noise temps 80-100 K (device later transferred to slot A4 of 'SIS harvested' gelpak) |
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LAB TESTS, 19 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-03 with WBA13 #179D this mixer has an NRAO C12,L56 device in it; last tested on 30may, was found to have soft IV curve and poor noise temps; today use 1 med, 1 small magnet as on 19feb08; supposedly there is still a 5 ohm resistor in series with the device IV curves still soft, noise temps 60 K min band D: 31-050-01 with new UVa C14,L56 device, WBA13 #169D; solenoid mods to mixer block: removed upside down section of microstrip, installed new short section to anchor SMA pin; 0.8 x 200 mil wirebond to microstrip; bias is 21.5 uA at 1 mV noise temps 50 K min, flattest passband we've seen! |
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LAB TESTS, 20 Jun 2008 dewar7 |
retest mixer 31-050-01 through miniflange to see if noise temps are better than through OMT mixer uses UVa C14,L56 device, WBA13 #169D; solenoid noise temps 47 K min, just a few K lower than through OMT |
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LAB TESTS, 24 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-04 with WBA13 #179D this mixer has ? device in it; wirebond length is 0.14"; photographed 20jun08 1 med, 1 small magnet; no tests: amplifier 179D stopped working when cold band D: 31-042-01 with WBA13 #81D; 1 med, 1 small magnet no tests: amp drew 45 mA regardless of gate bias |
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LAB TESTS, 24 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-04 with WBA13 #179D this mixer has ? device in it; wirebond length is 0.14"; photographed 20jun08 1 med, 1 small magnet; no tests: amplifier 179D stopped working when cold band D: 31-042-01 with WBA13 #81D; 1 med, 1 small magnet no tests: amp drew 45 mA regardless of gate bias |
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LAB TESTS, 25 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-04 with WBA13 #147D this mixer has ? device in it; wirebond length is ?; 1 med, 1 small magnet; this amp also draws 45 mA regardless of gate bias minimum noise 87 K band D: 31-042-01 with WBA13 #196D; 1 med, 1 small magnet device ?, wirebond length ?; minimum noise 52 K at 230 GHz |
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LAB TESTS, 27 Jun 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-042-04 with WBA13 #15D this mixer has ? device in it; wirebond length is ?; 1 med, 1 small magnet; no measurements of noise - scans show yfactor=1 always; band D: 31-042-01 with WBA13 #196D; 1 med, 1 small magnet device ?, wirebond length ?; change since 25 Jun ? minimum noise 54 K at 230 GHz |
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LAB TESTS, 03 Jul 2008 dewar9 |
band B: HIA-085 with WBA13 #169D; at room temp, 1mV = 14.5 uA noise temps disappointing, ~48 K confirmed that total pwr from dewar dropped by ~30 dB when WBA13 was turned off band D: 31-015A-7 with WBA13 #19D consistent with test results from 03aug06 |
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LAB TESTS, 06 Jul 2008 dewar9 operating at 60 / 14 / 3.3 / 3.4/ 3.4 K |
band B: HIA-188 with WBA13 #131D; at room temp, 1mV = 14.5 uA noise temps OK, passband measured only at 110 GHz, then fuse blew on compressor band D: 31-015A-7 with WBA13 #19D; at room temp, 1mV = 21.8 uA |
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LAB TESTS, 09 Jul 2008 dewar7 |
band B: HIA-084 with WBA13 #152D amp draws 20 mA with gate bias of just 0.25 V; note that test data from Hamdi show Vd=1V, Id=34 mA, Vg1=1.8 V, Vg2=0.45V at 15K noise temps ~100K ?! band D: 31-050-03 with WBA13 #169D; solenoid device ?, wirebond ? noise temps very scattered, about 76K minimum |
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LAB TESTS, 11 Jul 2008 dewar7 |
2 1mm mixers mounted on Custom Microwave OMT, using band B and D bias connections band B: 31-050-01 with WBA13 #179D, solenoid noise temps 57 K min initially, 46 K min after retest (moved LN2, swapped PAM) this is the first test of mixer 31-050-01 on the band B output of the OMT band D: 31-050-03 with WBA13 #159D; 1/2 small magnet in hole device ?, wirebond ? noise temps very scattered, about 67 K minimum |
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LAB TESTS, 16 Jul 2008 dewar13 |
band B: HIA-173 with WBA13 #169D; at room temp, 1mV = 14.5 uA noise temps OK, passbands flat; found that ice chunks on absorber raised trcvr from 36 to 60 K band D: 31-015-4A with WBA13 #47D; at room temp, 1mV = 22 uA noise temps consistent with those from ? |
