Re: 8662A - a warning about dangerous service directions
Hi George, This is not an issue with the loads being disconnected. When the overvoltage condition exists, HP advice is to bypass the safety shutdown and measure the voltages. With the normal loads in
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Dmitry Teytelman
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#126676
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Re: Info Need on a RF FET for a Agilent E4438C signal generator
I used this one for a similar job, worked fine, didn't need to modify the matching networks, https://www.digikey.ca/en/products/detail/macom-technology-solutions/XF1001-SC-0G00/5872554 You won't get
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Ovidiu Popa [Business]
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#126675
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Re: 8662A - a warning about dangerous service directions
Hi Dmitry Whilst I share your concerns may I say that the HP fault finding guidance is based around having a set of their 8622A or 8623A PCB card extenders available. Under most circumstances using
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george edmonds
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#126674
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Re: first post - new home lab - tips on using HP/Agilent gear
I replace the 75 ohm resistors that are in series with the output connectors with 50 ohm. The Inputs on the amps that I convert are high impedance, with loop through so I can easily configure a unit
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Michael A. Terrell
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#126673
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Re: 8662A - a warning about dangerous service directions
Dmitry, It always puzzled me that the manual advised you to bypass the over-voltage protection shutdown in the situation of a potentially damaging over-voltage condition. Seems to me that is only
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Tony
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#126672
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8662A - a warning about dangerous service directions
Hello, During a recent repair my 8662A went into shutdown due to the high input voltage at the linear regulator (A7A1) input. Service sheet 56 directs one to ground the collector of A7A1Q16 and then
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Dmitry Teytelman
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#126671
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Re: WTB: 5265A Digital Voltmeter for HP 5245L Electronic Counter.
Hi Stephen, do you still have the 5265A for sale? im in Australia, thanks Ben
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bencmansfield@...
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#126670
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Re: HP/Agilent/Keysight 8478B thermistor mount
Yes 8478B is a transfer power standard for 7mm connectors . It¡¯s very stable , the matching is not the best but with a good VNA are used as transfer standard on most national lab. The efficiency are
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Patricio A. Greco
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#126669
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Re: HP/Agilent/Keysight 8478B thermistor mount
If it was used in a standards lab it more than likely has option H01 which guarantees a VSWR < 1.05 at 50MHz , usually either the 8478B-H01 or 478A-H75 or H76 are used for the power level accuracy
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Lothar baier <Lothar@...>
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#126668
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Re: HP/Agilent/Keysight 8478B thermistor mount
This one came from an auction at McDonnell Douglas plant in St. Louis - It was in their standards lab - a long time ago. AFIK the "B" version is the only one available from HP Cheers! Quoting Lothar
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Bruce
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#126667
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Re: HP/Agilent/Keysight 8478B thermistor mount
I haven¡¯t seen any 8478B used as transfer standard , we used them with some special option to calibrate the 50MHz reference on 43x series meters , for sensor calibration we used a weinschel system2
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Lothar baier <Lothar@...>
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#126666
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Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable
Could you have used a single point frequency measurement n the VNA? I know the 8510 will do that. But I am sure the experience was educational - thanks for the education - it would have taken me a bit
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Bruce
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#126665
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Re: HP/Agilent/Keysight 8478B thermistor mount
I actually have one of these and treat it VERY carefully whenever I use it - which is infrequently Cheers! Bruce Quoting Lothar baier <Lothar@...>:
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Bruce
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#126664
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Re: HP/Agilent/Keysight 8478B thermistor mount
I certainly would call $14K outrageously expensive. Cheers! Bruce Quoting Lothar baier <Lothar@...>:
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Bruce
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#126663
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Re: HP 8662A Power up - overvoltage shutdown
Hi, Following the comments by G Edmonds in this thread he recommended loading the PSU -40V rail more heavily to resolve the PSU shutdown error occurring immediately after start-up. Pleased to say that
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Tony
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#126662
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Re: HP/Agilent/Keysight 8478B thermistor mount
They certainly can be, and certainly are, used as transfer standards. Further, NIST will calibrate them. (they won't calibrate any other type of RF power sensor, unless something has changed very
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Dave McGuire
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#126661
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Re: HP/Agilent/Keysight 8478B thermistor mount
i wouldnt call it a transfer standard , weinschel/tegam makes sensors that use the same principle that are heated (1109/1111)? that are used with system 2 units to calibrate sensors , they are
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Lothar baier <Lothar@...>
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#126660
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Re: HP/Agilent/Keysight 8478B thermistor mount
first of you have to consider that the 8478B just as the older 478 series requires a lot of manual assembly steps as it was designed in a time when there was no such thing as surface mount parts or
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Lothar baier <Lothar@...>
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#126659
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Re: HP/Agilent/Keysight 8478B thermistor mount
It is directed at a captive audience. This piece is used as the transfer standard for making power measurement calibrations and is required for certain procedures. If you want to play in a certain
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Bruce
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#126658
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Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable
Hello, There is one more issue to consider. Long lines give delays. Once I wanted to measure the loss of a coaxial cable on a vna. Was an interesting experience: no response. Until I realized the
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Harke Smits
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#126657
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