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
|
mixer damage due to overloading?
|
Re: HP 8753D Opt. 006 VNA YTO Problem
No chance it's the one in the 2784? ? -- john, KE5FX ?
toggle quoted message
Show quoted text
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
|
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
|
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.
|
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.
|
Thanks to all, I will investigate!
|
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 Aeron¨¢utico de Reparaci¨®n 1B-349Organizaci¨®n de Mantenimiento Aeron¨¢utico de la Defensa OMAD-001Gral. Mart¨ªn Rodr¨ªguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
toggle quoted message
Show quoted text
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 Aeron¨¢utico de Reparaci¨®n 1B-349
Organizaci¨®n de Mantenimiento Aeron¨¢utico de la Defensa OMAD-001
Gral. Mart¨ªn Rodr¨ªguez 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.
|
Re: HP 8594E low signal level indicated
Hi Greg,
Your recommendation of looking at first mixer output is still valid. Rik's SA is off by 30-40dB, few dB error in expected levels won't change debug approach. Block diagrams take some time to decipher, I spent quite some time on 8594E (tracking generator fix) and 8560E (YIG retrofit) block diagrams before.?
Ozan
toggle quoted message
Show quoted text
On Mon, Feb 27, 2023 at 10:18 AM, Greg Muir wrote:
Ozan,
?
Boy, did I make a big fluff!!? Your recent comment regarding the erroneous IF frequency in my last post brought me to take another look at the stage gains/levels that I had mentioned in that post.? From that I realized that I had pulled up the wrong documentation that was for the 8590 instead of the 8594 analyzer.? The last section containing this information in that email should be disregarded.
?
The HP ¡°Service Guide - HP 8590 Series Analyzers Assembly-Level Repair¡± document (08590-90300) appears to contain all of the necessary level/frequency information shown in the block diagram (foldout 9-4) to be able to further diagnose the problem.? As Rik had commented it can be a little daunting to try to decipher the information across various analyzer models but with careful attention across each stage it can be a great help if one simply uses a highlighter marker to indicate the information that only applies to the 8594E unit.
?
My apologies for any misleading information.? I was dealing with too many tasks at the time.
?
Greg
|
Re: HP 478A Thermistor head
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 ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Patricio A. Greco via groups.io
Sent: 27 February 2023 21:27
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 478A Thermistor head? How much goes down ? Did you sweep the sensor ? The input reflection coefficient is good tho check it.? Ing. Patricio A. Greco
Taller Aeron¨¢utico de Reparaci¨®n 1B-349
Organizaci¨®n de Mantenimiento Aeron¨¢utico de la Defensa OMAD-001
Gral. Mart¨ªn Rodr¨ªguez 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.
|
Re: HP 478A Thermistor head
How much goes down ? Did you sweep the sensor ? The input reflection coefficient is good tho check it.? Ing. Patricio A. GrecoTaller Aeron¨¢utico de Reparaci¨®n 1B-349Organizaci¨®n de Mantenimiento Aeron¨¢utico de la Defensa OMAD-001Gral. Mart¨ªn Rodr¨ªguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
toggle quoted message
Show quoted text
On 27 Feb 2023, at 11:24, Kenneth Harrison <bibpakak507@...> wrote:
? 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.
|
Re: HP 8594E low signal level indicated
Excellent idea - should be one of the first things down.
Cheers!
Bruce
Quoting Rik Rasmussen <rikrasmussen@...>:
toggle quoted message
Show quoted text
Today, I paused troubleshooting and recorded for backup, the Correction Constant Data using the forms in the service manual.
|
Re: HP 8594E low signal level indicated
Today, I paused troubleshooting and recorded for backup, the Correction Constant Data using the forms in the service manual.
|
Re: HP 8594E low signal level indicated
Good luck bug hunting !
Cheeras!
Bruce
Quoting "Greg Muir via groups.io" <big_sky_explorer@...>:
toggle quoted message
Show quoted text
Ozan,
Boy, did I make a big fluff!! Your recent comment regarding the erroneous IF frequency in my last post brought me to take another look at the stage gains/levels that I had mentioned in that post. From that I realized that I had pulled up the wrong documentation that was for the 8590 instead of the 8594 analyzer. The last section containing this information in that email should be disregarded.
The HP ¡°Service Guide - HP 8590 Series Analyzers Assembly-Level Repair¡± document (08590-90300) appears to contain all of the necessary level/frequency information shown in the block diagram (foldout 9-4) to be able to further diagnose the problem. As Rik had commented it can be a little daunting to try to decipher the information across various analyzer models but with careful attention across each stage it can be a great help if one simply uses a highlighter marker to indicate the information that only applies to the 8594E unit.
My apologies for any misleading information. I was dealing with too many tasks at the time.
Greg
|
Re: HP 8594E low signal level indicated
Ozan,
?
Boy, did I make a big fluff!!? Your recent comment regarding the erroneous IF frequency in my last post brought me to take another look at the stage gains/levels that I had mentioned in that post.? From that I realized that I had pulled up the wrong documentation that was for the 8590 instead of the 8594 analyzer.? The last section containing this information in that email should be disregarded.
?
The HP ¡°Service Guide - HP 8590 Series Analyzers Assembly-Level Repair¡± document (08590-90300) appears to contain all of the necessary level/frequency information shown in the block diagram (foldout 9-4) to be able to further diagnose the problem.? As Rik had commented it can be a little daunting to try to decipher the information across various analyzer models but with careful attention across each stage it can be a great help if one simply uses a highlighter marker to indicate the information that only applies to the 8594E unit.
?
My apologies for any misleading information.? I was dealing with too many tasks at the time.
?
Greg
|
Re: HP 478A Thermistor head
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.
|
?
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
|
Re: HP 8753D Opt. 006 VNA YTO Problem
alex@... writes: I have a 8753D VNA with Option 006. Unfortunately it stopped working and shows "No IF found: Check R Input Level". The problem is only at 3 to 3.8 GHz output frequency range.
I did all the tests according to the service manual "Source Troubleshooting" and found that:
- Service Menu Test "48" fails
- Source Tune Mode: There is no output signal from the YTO at the low end around 3 and 3.8 GHz
As I already found in other group topics it is a known problem that these YTOs fails at the low end. I tried to buy a replacement one and found one at alltest instruments. I bought it for 700 USD.
Unfortunately if I change the YTO to the "new" one, there is absolutely no output signal over the whole frequency range. If I put my defective YTO back in the VNA it works except the known problem from 3 to 3.8 GHz, off course.
I think the replacement one from alltest is a bad device. Is there anything I can check to confirm this? You can check test the YTO on the bench, or measure the YTO signal level directly at the YTO, leaving it in circuit so that your 8753 drives it for you. If you bench test it, make sure you know the proper signals to feed it and be careful (use current and voltage limits etc). It should be possible to figure out the correct drive signals by looking at the schematic. This video might also be of some help: Another thing to note is that YTO output power tends to be quite high. Depending on the spectrum analyzer you're using to measure it, it's probably not a bad idea to throw a 20dB attenuator in line with the output. It's a bit surprising that AllTest would have given you a bad part. They charge a significant premium to other places. But, from what I can tell, they're one of the few places that does proper tests on what they sell. Maybe I need to revise that impression. Anyway, let us know what you find. Good luck, Matt
|
Re: HP 8753D Opt. 006 VNA YTO Problem
Hallo Alex,
Unfortunately I can't give you great advice, but will say the following:
1)? When you replace certain parts of the instrument, you have to go through a full recalibration procedure to bring things into specification.? This includes especially the detectors & source module.? While I doubt that this is your issue, you may try it.? Once you get the hang of the procedure, it's not too bad.? Instructions are in the service manual.? You will however need a power meter and two power sensors (8141A and 8142A) as well as a few special cables (8120-4779).? You save the EPROM data to a 3.5" floppy (and probably do two just for safety) and then you can recalibrate the whole instrument.? Again, unlikely to fix your issue, but possibly worth a try.
2)? When I had an issue with my source module on a parts unit that I purchase, I purchased another parts unit on ebay for $1000 and managed to get lucky enough.? I used the parts that I needed and then split up the remaining working parts from the unit selling them individually on ebay to make back my $1000.? It was a bit of a pain, but resulted in essentially a "free" fix.
Based on what you are describing, I highly suspect something in the source module, but beyond that I'm going to have to defer to the experts on this one.? Viel gl¨¹ck!.
/Scott
|
Re: HP 8753D Opt. 006 VNA YTO Problem
One way to verify is to insert a directional coupler and measure the output of the yig at the coupled port. However, doing the double swap as you did should be proof enough. You got a bad one. It happens?
On Mon, Feb 27, 2023, 2:42 AM < alex@...> wrote: Hi,
I have a 8753D VNA with Option 006. Unfortunately it stopped working and shows "No IF found: Check R Input Level". The problem is only at 3 to 3.8 GHz output frequency range.
I did all the tests according to the service manual "Source Troubleshooting" and found that:
- Service Menu Test "48" fails
- Source Tune Mode: There is no output signal from the YTO at the low end around 3 and 3.8 GHz
As I already found in other group topics it is a known problem that these YTOs fails at the low end. I tried to buy a replacement one and found one at alltest instruments. I bought it for 700 USD.
Unfortunately if I change the YTO to the "new" one, there is absolutely no output signal over the whole frequency range. If I put my defective YTO back in the VNA it works except the known problem from 3 to 3.8 GHz, off course.
I think the replacement one from alltest is a bad device. Is there anything I can check to confirm this?
best regards
Alex
--
Ken H.
|
Froggie the Gremlin
Patricio A. Greco
Paul Bicknell
Rik Rasmussen WA4BAN