Re: HP 3457A FET Transistors
OK, thanks David
I assume I can email you back directly, is that correct ?
Best Regards
CRAIG MAYFIELD | Director - Particle & Environmental Technologies
Alpha Scientific Pty Ltd
Melbourne Office
Phone: (03) 9893 3972
Mobile: 0413 124 589
Email: craig@...
Website: www.alphascientific.com.au
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Dave McGuire Sent: Thursday, 2 March 2023 11:45 AM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP 3457A FET Transistors On 3/1/23 18:31, Craig Mayfield wrote: I have only just joined this group earlier today and am still trying
to work out how to navigate my way around It is a mailing list with a (poor) web front end. You'll find it works a whole lot better as a mailing list, rather than trying to use it as a "web forum". Just FYI. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: HP 3457A FET Transistors
On 3/1/23 18:31, Craig Mayfield wrote: I have only just joined this group earlier today and am still trying to work out how to navigate my way around It is a mailing list with a (poor) web front end. You'll find it works a whole lot better as a mailing list, rather than trying to use it as a "web forum". Just FYI. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Dear Sir / Madam
?
I have only just joined this group earlier today and am still trying to work out how to navigate my way around
?
I have a HP 3457A and it keeps giving me an error 256. I have replaced the filter caps and followed the steps in as shown in a series of YouTube videos and I can get the diagnostic 8 to pass most of the time, however it then fails. On the YouTube series, the guy replaced 6 of the FETS as shown in the attached document. I am trying to find modern equivalents of these to order them. I have contacted Keysight and Element 14 to no avail. Can someone suggest a part number and or brand of FET I can use which should do the job as per the manufacturers original specs ?
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HP 3457A FET Requirements
Dear Sir / Madam ? I have only just joined this group earlier today and am still trying to work out how to navigate my way around ? I have a HP 3457A and it keeps giving me an error 256. I have replaced the filter caps and followed the steps in as shown in a series of YouTube videos and I can get the diagnostic 8 to pass most of the time, however it then fails. On the YouTube series, the guy replaced 6 of the FETS as shown in the attached document. I am trying to find modern equivalents of these to order them. I have contacted Keysight and Element 14 to no avail. Can someone suggest a part number and or brand of FET I can use which should do the job as per the manufacturers original specs ? ? Best Regards ? CRAIG MAYFIELD | Director - Particle & Environmental Technologies Alpha Scientific Pty Ltd Melbourne Office ? Phone: (03) 9893 3972 Mobile: 0413 124 589 ? Email: craig@... Website: ? 
? This e-mail message and any attachments are subject to copyright and they are intended only for the addressee and may contain confidential or privileged information. Confidentiality and privilege are not waived if you are not the intended recipient of this e-mail, nor may you use or retain, or disclose, copy or forward to any third party this e-mail, or any information contained in or attached to it. If you received this e-mail in error please delete it (and any copy of it from your computer system) and kindly notify the sender by reply e-mail. Alpha Scientific Pty Ltd does not warrant that this e-mail and / or any attachments are error or virus free and recommends that all attachments be scanned / checked for computer viruses. ?  
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Greetings. An associate suggested that this group may be able to assist me. I have a HP 3457A multimeter and I keep getting error 256. I have followed the steps on a YouTube series where the guy replaces caps and various components including some FET transistors. I adjust the pot back and forwards and get the Diagnostic 8 to PASS on 0 many times, however it keeps failing high or low occasionally and thus failing the SELF TEST. I am trying to locate direct replacements for the FET transistors shown in the attached image from the manual. I have contacted Keysight, and they cannot help. I have contacted Element 14 and they suggested some options, however they were not sure. I was wondering if anyone knows the BEST direct replacement for these as I need to order 6 of them asap. Best Regards. Craig
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Re: 5086-7337 *Yig Oscillator issue*
Hi Ruben,
I don’t have a direct answer to your question. But, if you haven’t already seen it, this webpage may be helpful to you:
Matt
Hello there!
These days I have been thinking about the fate of this project. I am referring to the 83592A plugin and the 8350B mainframe, which have not turned out to be excellent investments (although they were at a didactic level, that’s for sure).
If finally it’s toasted, I don't feel like buying an YIG oscillator. What's more, I don't feel like putting more money into this project.?
I've been thinking of making a tracking generator for my 8566B out of it. Bands 0 and 1. I heard it’s fairly easy to do.?I imagine doing that on the other bands also need to align the SYTM of the plugin with the SA, and that’s impossible,?what you?think?
Regards,
Ruben
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Re: 5086-7337 *Yig Oscillator issue*
Hello there!
These days I have been thinking about the fate of this project. I am referring to the 83592A plugin and the 8350B mainframe, which have not turned out to be excellent investments (although they were at a didactic level, that’s for sure).
If finally it’s toasted, I don't feel like buying an YIG oscillator. What's more, I don't feel like putting more money into this project.?
I've been thinking of making a tracking generator for my 8566B out of it. Bands 0 and 1. I heard it’s fairly easy to do.?I imagine doing that on the other bands also need to align the SYTM of the plugin with the SA, and that’s impossible,?what you?think?
Regards,
Ruben
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Hello,
Not even a cent perhaps, but I had intermittent phase lock issues on my 8341A. It turned out to be a bad cap within the 200-300 MHz VCO (C13 on A36). This was not immediately obvious from quick measurements, but replacing the bad cap (measured 35 Ohms after desoldering...) made the generator work again.
Best of luck with your investigation!
Regards,
? Staffan
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Re: HP transistor equivalent for 1854-0247?
Which equipment have this transistors?? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
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On 1 Mar 2023, at 12:30, gren <hrgerson@...> wrote:
? Don, I am looking for more info on the HP Germanium transistors: 1850-, 1851-, 1852- prefixes Do you have any further info? lists, data sheets, specifications,? about these ? thanks, On Sat, Feb 25, 2023 at 08:51 PM, Don Bitters wrote:
Also all ?1853- prefixes are PNP silicon type, all 1854- are NPN silicon type, all 1850-, 1851-, 1852- prefixes are germanium type transistors.
?
Don Bitters
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This is going to sound weird but check for common mode noise on the power line. Especially If using ANYTHING that talks on the power line.?
I have a power monitoring unit in the lab that TED unit that does power line communication that causes me intermittent issues.
Modern washing machine are also a HUGE source of broad spectrum noise based on the 3phase induction motors
Any power line networking gear should be suspect as well. This would put HF signals on the ac line.?
My personal lab has a chirp that comes around interment that I thought was the wifi network beacon time but it was not. This cause me no end of grief when I was aligning a tek aa501/a and working with some ultra low distortion. It also caused the spec ans to go nuts. Tested on 3.?
Also check your ground and make sure nothing is leaking current on the ground line this can cause some very strange things when the refrence is moving around.
When looking for noise especally broad spectrum noise and old AM radio is a good tool. I that solved wifi issues with simple radio.
Eric
What mixer? The SA is fine..
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What mixer? The SA is fine..
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Re: HP transistor equivalent for 1854-0247?
Does the attached pdf help-I have more if it does ? Regards Mike g4wam ?
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From: [email protected] [mailto:[email protected]] On Behalf Of gren
Sent: 01 March 2023 17:02
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP transistor equivalent for 1854-0247? ?
Don,
I am looking for more info on the HP Germanium transistors:
1850-, 1851-, 1852- prefixes
Do you have any further info? lists, data sheets, specifications,? about these ?
thanks,
On Sat, Feb 25, 2023 at 08:51 PM, Don Bitters wrote:
Also all ?1853- prefixes are PNP silicon type, all 1854- are NPN silicon type, all 1850-, 1851-, 1852- prefixes are germanium type transistors.
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Re: HP transistor equivalent for 1854-0247?
Don,
I am looking for more info on the HP Germanium transistors:
1850-, 1851-, 1852- prefixes
Do you have any further info? lists, data sheets, specifications,? about these ?
thanks,
toggle quoted message
Show quoted text
On Sat, Feb 25, 2023 at 08:51 PM, Don Bitters wrote:
Also all ?1853- prefixes are PNP silicon type, all 1854- are NPN silicon type, all 1850-, 1851-, 1852- prefixes are germanium type transistors.
?
Don Bitters
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mixer damage due to overloading?
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Re: HP 8753D Opt. 006 VNA YTO Problem
No chance it's the one in the 2784? ? -- john, KE5FX ?
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From: [email protected] [mailto:[email protected]] On Behalf Of alex@...
Sent: Tuesday, February 28, 2023 12:59 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8753D Opt. 006 VNA YTO Problem? After checking all voltages once again and connected the spectrum analyzer to the YIG output directly - the delivered YTO is definitly bad.
Alltest will replace it. That's the good news.
Alex
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Re: HP 8753D Opt. 006 VNA YTO Problem
After checking all voltages once again and connected the spectrum analyzer to the YIG output directly - the delivered YTO is definitly bad.
Alltest will replace it. That's the good news.
Alex
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A few years ago I retrofitted the tracking generator option to my 8595E analyzer. I’m pretty sure the LO distribution amplifier (LODA) had a bias value written on the top label. There is a trim pot on the control board for setting the bias. All the information should be in the 8590 series service manual. You just have to fish through it and pick out your applicable unit.
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Advice or a little driver help needed with an E5504A phase noise measurement system wand VXI digitizer
I have a VXI frame with an E1430A 10msps ADC.
I managed to get an older 32 bit version running on a windows 7 box (not my first choice but attempted path of least resistance to start with) but think I might be missing some files that came neither with the installer nor the prerequisites.
The E1430 asset control panel appears to “connect” but everything is grayed out. No beat note is detected, and until it’s calibrated it won’t let me open the real time view which should just be a frequency domain output from the baseband after going through a low noise amplifier to drive the ADC.
I hesitate to even considering trying source a PCI-6111 card without knowing it too won’t have a similar problem. The E1430 is technically better hardware anyway.
also: I’m using either an E8491B or an NI VXI-MXI-2 in slot 0, so there’s no E1406A/B to provider SCPI services for register based devices.
if anyone has access to an installer or recovery CD, I’d be looking for the PC_Digitizer directory contents.
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Thanks to all, I will investigate!
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Re: HP 478A Thermistor head
I had problems with a H75 option and I found a bad contact . I recommend to disassemble the unit carefully.? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
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On 27 Feb 2023, at 17:18, Paul Bicknell <admin@...> wrote:
? Hi thank you for the return Emails I will do a frequency sweep but we are talking down by several ?Dbm at 100 Mhz I am 99.9 % convinced it is a problem with the series cap Regards Paul ? ? How much goes down ? Did you sweep the sensor ? The input reflection coefficient is good tho check it.? Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T:?+5411-4455-2557
F:?+5411-4032-0072
? Low end roll could be connector or bellows cap, guessing the later, but remote diagnostic is asking for trouble. Willing to help ? On Mon, Feb 27, 2023, 7:43 AM Paul Bicknell <admin@...> wrote: ? Hi? I have a HP 478A Thermistor head that works OK above 2 Ghz but reads low below 2 Ghz I assume there is a problem with the internal series capacitor Has anyone had a similar fault and is there any advice on a repair ? Regards Paul
--
Ken H.
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Dave McGuire
RubenRubio
Patricio A. Greco
Froggie the Gremlin