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3586A Error 3.1 repaired..thanks to Didier
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J.Byers
Hi Hank
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HP Journal below has 3586A/B/C introductory article PL Thomas "A programmable selective level meter (wave analyzer) with synthesized tuning, autoranging, and automatic calibration", HEWLETT PACKARD JOURNAL, May, 1980 Vol 31, Number 5 Pages 3 thro 8 Thats from my catalog index. I cant find all my issues at present (shifted house 2 years ago and much of my stuff packed to the roof in a garden shed, I cant even open the door without stuff cascading out!). If I come across it I will email the pages to you Best regards JBEE (John Byers) ----- Original Message -----
From: Henry Kolesnik <kolesnik@...> To: <hp_agilent_equipment@...> Sent: Monday, August 08, 2005 10:34 PM Subject: Re: [hp_agilent_equipment] 3586A Error 3.1 repaired..thanks to Didier Johntheir Journal about the 3586 series? |
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hpxref
My 3586A E3.1 repair:
Many thanks to Didier (#1759)for his spot on suggestion as to the fix for the 3.1 error on my 3586A. One difference: My VCXO oscillator was oscillating amplitude wise OK, but had drifted low in frequency. Others may benefit from my particular fix, different from Didiers, so here goes. With 3586A and measuring instruments warmed up 4 hours from cold at 20 deg C room temp:- Instrumentation used: HP34401A DMM, HP5316A Freq Cntr (with opt 001,but external frequency in at rear fed from HP3586A HI STAB TCXO 10MHz out). Systron Donner DL40 dual PSU fed in turn to 50k 10 turn Helipot, bridge connected with center arm providing a variable external + / - Vco via screened leads, +/- 8.6v, adjusted in 1.000v increments as monitored on DMM. A small pi section RF filter with a 100Hz LC `trap' section was used in series with Vco leads into A11 to reduce any outside interference. (50Hz line frequency over here). The above instruments were in turn fed from an Advance CVN250A AC regulator, waveform corrected 3586 Adjustments (A11 board): Adjusting the slug outwards in L22 did not quite pull the XTAL enough to lock, but unsoldering the XTAL case to its ground post and lifting it up clear of the ground plane beneath did the trick here. The reduction in XTAL case capacitance to deck raised its freq enough in this case and no other changes to components were needed. Before this fix my VCXO had resistor R27 lifted and an external voltage fed to the cold end to check for frequency swing: At 0.000 v Y20 (XTAL) frequency was 49.982775 Mhz, some 1600Hz lower than it should have been I measured a total deviation in Y20 frequency of from 2775Hz change (+8.600 v in) to 3989Hz change for – 8.600 v in.) After Xtal case lifted off ground and slug at minimum insertion, (the now correctly locked case) total deviation for the same external Vco inputs was: 1339 Hz change for +8.600 v in and 1772 Hz change for – 8.600 v in or a total excursion of 3,111 Hz from the XTALs center frequency With R27 re connected and external Vco removed, test point TP1 now indicated a correctly locked frequency of 49.984375 MHz as indicated on my 5316A counter. Note that my total frequency excursion is near the same as the 3kHz Didier experienced after adding extra C to Q22 on his unit. So this value may well be close to HP's original specification as the only circuit modification to mine was lifting the ground of the XTAL case. As this is a relatively simple mod to make, others may find the same in their case, avoiding changes or additions at the component level. Again, many thanks to Didier for pointing out the area to check, allowing my 3586A to work as it should (a lot less annoying whistles and a normal dB readout of signals received at last!)… and for the much appreciated downloaded details of the 3586A, a truly magnificent piece of instrumentation and a tribute to HP's designers ! JBEE (John Byers) |
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John
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Thanks for the tip, I'll file it away just in case I ever need to do it on my 3586C. I'm still trying to find out if HP published an article in their Journal about the 3586 series? tnx 73 Hank WD5JFR ----- Original Message -----
From: "hpxref" <face1941@...> To: <hp_agilent_equipment@...> Sent: Monday, August 08, 2005 1:47 AM Subject: [hp_agilent_equipment] 3586A Error 3.1 repaired..thanks to Didier My 3586A E3.1 repair: Many thanks to Didier (#1759)for his spot on suggestion as to the fix for the 3.1 error on my 3586A. One difference: My VCXO oscillator was oscillating amplitude wise OK, but had drifted low in frequency. Others may benefit from my particular fix, different from Didiers, so here goes. With 3586A and measuring instruments warmed up 4 hours from cold at 20 deg C room temp:- Instrumentation used: HP34401A DMM, HP5316A Freq Cntr (with opt 001,but external frequency in at rear fed from HP3586A HI STAB TCXO 10MHz out). Systron Donner DL40 dual PSU fed in turn to 50k 10 turn Helipot, bridge connected with center arm providing a variable external + / - Vco via screened leads, +/- 8.6v, adjusted in 1.000v increments as monitored on DMM. A small pi section RF filter with a 100Hz LC `trap' section was used in series with Vco leads into A11 to reduce any outside interference. (50Hz line frequency over here). The above instruments were in turn fed from an Advance CVN250A AC regulator, waveform corrected 3586 Adjustments (A11 board): Adjusting the slug outwards in L22 did not quite pull the XTAL enough to lock, but unsoldering the XTAL case to its ground post and lifting it up clear of the ground plane beneath did the trick here. The reduction in XTAL case capacitance to deck raised its freq enough in this case and no other changes to components were needed. Before this fix my VCXO had resistor R27 lifted and an external voltage fed to the cold end to check for frequency swing: At 0.000 v Y20 (XTAL) frequency was 49.982775 Mhz, some 1600Hz lower than it should have been I measured a total deviation in Y20 frequency of from 2775Hz change (+8.600 v in) to 3989Hz change for - 8.600 v in.) After Xtal case lifted off ground and slug at minimum insertion, (the now correctly locked case) total deviation for the same external Vco inputs was: 1339 Hz change for +8.600 v in and 1772 Hz change for - 8.600 v in or a total excursion of 3,111 Hz from the XTALs center frequency With R27 re connected and external Vco removed, test point TP1 now indicated a correctly locked frequency of 49.984375 MHz as indicated on my 5316A counter. Note that my total frequency excursion is near the same as the 3kHz Didier experienced after adding extra C to Q22 on his unit. So this value may well be close to HP's original specification as the only circuit modification to mine was lifting the ground of the XTAL case. As this is a relatively simple mod to make, others may find the same in their case, avoiding changes or additions at the component level. Again, many thanks to Didier for pointing out the area to check, allowing my 3586A to work as it should (a lot less annoying whistles and a normal dB readout of signals received at last!). and for the much appreciated downloaded details of the 3586A, a truly magnificent piece of instrumentation and a tribute to HP's designers ! JBEE (John Byers) Yahoo! Groups Links |
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Thanks to John Byers there's a HP Journal article on the 3586.
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Does anyone have the issue that they can scan? HP Journal below has 3586A/B/C introductory article HEWLETT PACKARD JOURNAL, May, 1980 Vol 31, Number 5 Pages 3 thro 8 PL Thomas "A programmable selective level meter (wave analyzer) with synthesized tuning, autoranging, and automatic calibration", I'd sure like to read it in any form. 73 Hank WD5JFR ----- Original Message -----
From: "J.Byers" <face1941@...> To: <hp_agilent_equipment@...> Sent: Saturday, January 04, 1997 2:14 AM Subject: Re: [hp_agilent_equipment] 3586A Error 3.1 repaired..thanks to Didier Hi Hank |
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