Re: Hp 400D serial number decoder
I will guess the power supply electrolytics were manufactured by Sprague. When I worked at HP in the early 70¡¯s, Sprague was their preferred vendor. The Sprague electrolytics all had a 4 digit manufacturing date code¡ª yyww. yy is the last two digits of the year and ww is the week number.
While this doesn¡¯t precisely date the instrument, it puts a bound on the instrument manufacturing date obviously later than the latest component manufacturing date code. Identifying various date codes is a useful skill.
73 Jeff Furman AD6MX
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Re: Hp 400D serial number decoder
Thanks Jim for narrowing down the dates. ?
Good suggestions on changed out the large paper caps.?
I do have a couple other project ahead of this meter.?
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On Aug 30, 2022, at 7:21 AM, Jim Adney <jadney@...> wrote:
?On Tue, Aug 30, 2022 at 01:03 AM, Dave Miller wrote:
A 400D found it¡¯s way home tonight.?
I am trying to decode serial number to approximate its vintage.?
Serial number is 16210. ?That does not seem to fit into any of the decoders I have found to online to date.?
That's a mid- to late- 1950s vintage. The coding of the date into the serial prefix did not start until 1960. Before 1960, HP just used a plain serial number. After 1960, HP used a serial prefix that encoded the year and week the design was finalized, then a letter followed by a sequencial serial number. I found a error notice from HP on the 400D, dated 1959, that talked about serial nos. before 29721, so yours must be well before 1959. The first thing to do with your 400D is to replace all 4 of the large paper caps. These are ALL bad (leaky) by now. Three are plate to grid coupling caps in the amplifier stages and one is in the power supply. The three will pull the following grids up high putting those tubes into way too much conduction. Each of those three is in parallel with a mica cap for higher frequencies. The micas are usually fine, but I've had one that was also leaky. Check the grid voltages when you think you're done, to make sure none of them are still being pulled high. Leakage in the 4th cap doesn't seem to bother the power supply, but you might as well replace it anyway, while you're at it.
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Hello Jeff,
?
I have an HP 8640B to repair for a fellow radio amateur. When it
came to me, none of the knobs would move, and it appeared as though someone had
used a pipe wrench to turn the frequency band select knob ¨C the wing was broken
off. Internally, the gears were stripped and many bearings were seized up.
After an overall lubrication and replacement of stripped gears, I got it going
again, except that the frequency readout doesn¡¯t work.
?
To get this set back to serviceable condition, I want to replace
the frequency band select knob and the frequency counter. Can you help, please?
?
Cheers, Brian, VK2GCE (Australia)
?
?
I
have several parts units I bought to keep mine that I used to teach with going.
Not needed any longer, so if you need something, get in touch and I can pull
the part out. I suspect the fingers are gone on the bandswitch, which is why
these were sold as parts. Otherwise complete.
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Below is a high level YIG tuning coil freq v current graph. 50 mA is to low, 125mA is about mid range 3-7GHz based on a similar HP YIG from a HP-8594E. 
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Howdy all,
I'm working on an 8753A and it seems that I am having an issue with the B channel.? I noticed this when I went to check the loss on a cable and ran an S21 scan that gave me some really wonky readings.? I did some digging in the manual and ran through some of the test - specifically Test 17 (ADC Linearity Test) which promptly failed.? ?This led me to run a receiver noise test and it confirmed what I was seeing - B isnt working so good.? From the receiver noise test on A I get a reading of 15uU (about -96db within spec) and on B I get a reading of 60 mU ( -25db not so good).? I swapped the receivers for A and B and get pretty much the same result and I'm a little suck at this point on what to look at next.? I know there are a few test points on A10 but I can't find any values for them.? I do know that just casually probing in the mv range I get the following but not sure the data is meaningful -
After the gain stage on A10
TP3 - I get a fluctuation of about -29 to -31 mv (A)
TP6 - I get a steady 31.5 mv - no fluctuation (B)
Before the gain stage on A10
TP 18 - I get -31.5 mv which seems pretty steady (A)
TP 20 - I get -1mv (B)
I've also pulled the bottom cover off and pulled the A10 card out and measure the same voltages at P1 4 (A TP18) and 7 (B TP20) without the A10 card in place.? Any help at this point is appreciated.
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Anyone know how I can get an E1437A calibrated? (Keysight says they no longer support this product)
I'm hoping one of you guys knows where I can get a VXI?E1437A board calibrated.? It's for work, and I tried to get Keysight to cal it, but after 2 weeks they said they are unable as their cal software no longer works.?
Prefer a location in the US if possible.
Thank you,
Dave
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A lot of them tune at 20 MHz/mA, so 100 mA may not have been enough.? I'd crank the main coil current up to 200 mA and see if that makes a difference. ? -- john, KE5FX ?
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From: [email protected] [mailto:[email protected]] On Behalf Of piecolav via groups.io
Sent: Monday, August 29, 2022 10:09 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO? Today I tried to power the YTO 5086-7906, that of the 8563E, externally to the analyzer.
Granted that I have checked all the components of the small PCB on the oscillator, I noticed that the current absorbed values are:
+5 VDC, 98 mA
+15 VDC, 28 mA
-15VDC, 1mA
I also powered the main coil (pins 5 and 6) with a current from 50 to 100 mA, not knowing the exact operating value.
By adjusting the latter, the value read on the power meter does not change: about -28 dBm. Instead of the expected +10 dBm!
Now I'm sure the YTO is broken.
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Hi Ed, unfortunately the RF signal output connection is via a female SMA connector. The YTO 5086-7906 is built very well, as per HP tradition, and it is also easy to open it, having a little foresight and in a non-dusty environment.
I opened one of the two, broken, that I have, to check if inside there were any burn marks or gold wires, welded with the wire bonding technique, interrupted. Unfortunately, even with the microscope I did not find anything abnormal.
Opening the YTO is very easy: just remove the locked rear cover and unscrew the rear spacers.
The oscillator thus opens in two parts, the rear contains the two windings of the MAIN COIL and the FM COIL and the front contains all the electronic circuitry I believe on a sapphire substrate, including the ball in yttrium iron garnet.
Much of what I know I learned from reading the Keysight forum thread at: https://community.keysight.com/forums/s/question/0D52L00005IdorQSAR/hp-8560e-spectrum-analyzer-yig-yto- a11-questionproblem
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I have several parts units I bought to keep mine that I used to teach with going. Not needed any longer, so if you need something, get in touch and I can pull the part out. I suspect the fingers are gone on the bandswitch, which is why these were sold as parts. Otherwise complete.
Jeff Kruth
kmec@...
In a message dated 8/30/2022 11:35:15 AM Eastern Standard Time, ktx85@... writes:
?
Ok....is there someplace I can find parts to repair mine....
?
I am not the original owner...how can I tell if they have gone to far and done any damage to the VFO ?
?
?
-------- Original message --------
From: Dave Wise <david_wise@...>
Date: 8/30/22 9:53 AM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
?
The eight-turn stop is essential.? If you go more than eight turns and smash the back end of the cavity, the VFO is irreparably ruined.
I don¡¯t know what is safe to degrease that plastic.
?
?
-------- Original message --------
Date: 8/29/22 6:07 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
What about the small bit of plastic on each side of the cam closest to the pin that has worn away on each side creating a small ramp....?? ?What do you suggest to use as a cleaning agent or solvent?
I haven't posted very many times and tried to resend the pictures...
-------- Original message --------
Date: 8/29/22 6:00 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
The stacked plates of the eight-turn stop should be free to rotate with respect to each other to the limits of their respective dogs.? Sounds like yours have frozen together into a single rigid lump.? You¡¯ll need to free them up, degrease with something that doesn¡¯t attack them, and put on a bit of fresh grease.
?
HTH,
Dave Wise
?
?
Hello all,
I recently acquired a hp8640b..
With a quick.? Checkout all seems to function...EXCEPT a detent in the frequency generator...when it hits this plastic (cog) it makes it very difficult to tune the frequency...( it does tune.)? This is my first generator and I have searched the internet for this issue elsewhere....it appears that all the other places I have found a picture of these cogs( think combination lock tumblers ) they are spaced out and not all bunched togeather like stair steps as in my picture...I have a red pointer pointing at the issue....the metal pin hits the cog on each revolution of the dial
I look forward to your help in this repair. And sourcing the parts to repair it...I am also looking for 1 black foot
73
Ktx85@...?
|
Ok....is there someplace I can find parts to repair mine....
I am not the original owner...how can I tell if they have gone to far and done any damage to the VFO ?
toggle quoted message
Show quoted text
-------- Original message --------
From: Dave Wise <david_wise@...>
Date: 8/30/22 9:53 AM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
The eight-turn stop is essential.? If you go more than eight turns and smash the back end of the cavity, the VFO is irreparably ruined.
I don¡¯t know what is safe to degrease that plastic.
?
?
-------- Original message --------
Date: 8/29/22 6:07 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
What about the small bit of plastic on each side of the cam closest to the pin that has worn away on each side creating a small ramp....?? ?What do you suggest to use as a cleaning agent or solvent?
I haven't posted very many times and tried to resend the pictures...
-------- Original message --------
Date: 8/29/22 6:00 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
The stacked plates of the eight-turn stop should be free to rotate with respect to each other to the limits of their respective dogs.? Sounds like yours have frozen together into a single rigid lump.? You¡¯ll need to free them up, degrease
with something that doesn¡¯t attack them, and put on a bit of fresh grease.
?
HTH,
Dave Wise
?
?
Hello all,
I recently acquired a hp8640b..
With a quick.? Checkout all seems to function...EXCEPT a detent in the frequency generator...when it hits this plastic (cog) it makes it very difficult to tune the frequency...( it does tune.)? This is my first generator and I have searched the internet for
this issue elsewhere....it appears that all the other places I have found a picture of these cogs( think combination lock tumblers ) they are spaced out and not all bunched togeather like stair steps as in my picture...I have a red pointer pointing at the
issue....the metal pin hits the cog on each revolution of the dial
I look forward to your help in this repair. And sourcing the parts to repair it...I am also looking for 1 black foot
73
Ktx85@...?
|
The eight-turn stop is essential.? If you go more than eight turns and smash the back end of the cavity, the VFO is irreparably ruined.
I don¡¯t know what is safe to degrease that plastic.
?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]>
On Behalf Of Dave . via groups.io
Sent: Monday, August 29, 2022 4:11 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
?
-------- Original message --------
Date: 8/29/22 6:07 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
What about the small bit of plastic on each side of the cam closest to the pin that has worn away on each side creating a small ramp....?? ?What do you suggest to use as a cleaning agent or solvent?
I haven't posted very many times and tried to resend the pictures...
-------- Original message --------
Date: 8/29/22 6:00 PM (GMT-06:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Hp8640b
The stacked plates of the eight-turn stop should be free to rotate with respect to each other to the limits of their respective dogs.? Sounds like yours have frozen together into a single rigid lump.? You¡¯ll need to free them up, degrease
with something that doesn¡¯t attack them, and put on a bit of fresh grease.
?
HTH,
Dave Wise
?
?
Hello all,
I recently acquired a hp8640b..
With a quick.? Checkout all seems to function...EXCEPT a detent in the frequency generator...when it hits this plastic (cog) it makes it very difficult to tune the frequency...( it does tune.)? This is my first generator and I have searched the internet for
this issue elsewhere....it appears that all the other places I have found a picture of these cogs( think combination lock tumblers ) they are spaced out and not all bunched togeather like stair steps as in my picture...I have a red pointer pointing at the
issue....the metal pin hits the cog on each revolution of the dial
I look forward to your help in this repair. And sourcing the parts to repair it...I am also looking for 1 black foot
73
Ktx85@...?
|
Re: Hp 400D serial number decoder
On Tue, Aug 30, 2022 at 01:03 AM, Dave Miller wrote:
A 400D found it¡¯s way home tonight.?
I am trying to decode serial number to approximate its vintage.?
Serial number is 16210. ?That does not seem to fit into any of the decoders I have found to online to date.?
That's a mid- to late- 1950s vintage. The coding of the date into the serial prefix did not start until 1960. Before 1960, HP just used a plain serial number. After 1960, HP used a serial prefix that encoded the year and week the design was finalized, then a letter followed by a sequencial serial number. I found a error notice from HP on the 400D, dated 1959, that talked about serial nos. before 29721, so yours must be well before 1959. The first thing to do with your 400D is to replace all 4 of the large paper caps. These are ALL bad (leaky) by now. Three are plate to grid coupling caps in the amplifier stages and one is in the power supply. The three will pull the following grids up high putting those tubes into way too much conduction. Each of those three is in parallel with a mica cap for higher frequencies. The micas are usually fine, but I've had one that was also leaky. Check the grid voltages when you think you're done, to make sure none of them are still being pulled high. Leakage in the 4th cap doesn't seem to bother the power supply, but you might as well replace it anyway, while you're at it.
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Re: Hp 400D serial number decoder
Thanks Jeremy, That fills in the missing information. I have found other information that says they started in 1954. Cool Thank you very much.
Dave ?
On Tue, Aug 30, 2022 at 6:46 AM Jeremy Nichols < jn6wfo@...> wrote: Early HP serial numbers did not use a date reference. All we can tell is that it was before 1960. When I get up, I¡¯ll see if I can learn when the 400D was introduced. For now, my guess would be ¡°late 1950s.¡±
On Mon, Aug 29, 2022 at 11:04 PM Dave Miller < ve7hr@...> wrote: A 400D found it¡¯s way home tonight.?
I am trying to decode serial number to approximate its vintage.?
Serial number is 16210.? That does not seem to fit into any of the decoders I have found to online to date.?
The online manual I have found does mention that serial number range but the is not copyright date on the manual.?
Thanks
Dave
Jeremy Nichols
6.
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Re: Hp 400D serial number decoder
Early HP serial numbers did not use a date reference. All we can tell is that it was before 1960. When I get up, I¡¯ll see if I can learn when the 400D was introduced. For now, my guess would be ¡°late 1950s.¡±
On Mon, Aug 29, 2022 at 11:04 PM Dave Miller < ve7hr@...> wrote: A 400D found it¡¯s way home tonight.?
I am trying to decode serial number to approximate its vintage.?
Serial number is 16210.? That does not seem to fit into any of the decoders I have found to online to date.?
The online manual I have found does mention that serial number range but the is not copyright date on the manual.?
Thanks
Dave
|
Re: Hp 8590a spectrum analyzer
I have ordered the replacement caps from mouser. I was noticing a sticker on the side of the power supply board that shown the test points and voltages but I can't find them on the power supply board. Is that indicating a molex connector ? Maybe I overlooked something.? Also I did find a lose screw on the if board. I left the unit on for 2 hours and it passed the confidence test. Did it again and it failed.. I hate intermittent troubles. How important is the noise fail ??
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Re: Large assortment of H-P parts available
On Mon, 29 Aug 2022 at 20:03, greenboxmaven via <ka2ivy= [email protected]> wrote:
Could you please repost the list of
equipment in PDF format, so eveyone can read it? Thamks,
Bruce Gentry. KA2IVY
Or you could download LibraOffice, OpenOffice or I expect any number of other programs. LibraOffice works well.
Dave
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Re: Large assortment of H-P parts available
Hello Bob,
?
I can¡¯t open your xlsx document.
?
Can you help with the HP-3476A DMM? I have two in which the
hybrid 1813-0091 has failed.
?
Cheers, Brian
?
?
?
I've uploaded an inventory of what we've found so far. The
list is shorter than we thought. More parts may be uncovered in the future.
/g/HP-Agilent-Keysight-equipment/files/hpparts.xlsx
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Re: Hp 400D serial number decoder
I have been told that the "16" part means 16 years since 1960 so about 1976.
regards
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Hp 400D serial number decoder
A 400D found it¡¯s way home tonight.?
I am trying to decode serial number to approximate its vintage.?
Serial number is 16210. ?That does not seem to fit into any of the decoders I have found to online to date.?
The online manual I have found does mention that serial number range but the is not copyright date on the manual.?
Thanks
Dave
|
Re: Boonton 25A Power Meter Calibrator ¡°error.¡±
Buyer beware. Sometimes it's the small things that get you.
Stuart k6yaz
Los Angeles, California
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Brian
Jeremy Nichols
Dr. David Kirkby, Kirkby Microwave Ltd