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 ?
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-------- 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.
?
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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.
|
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.
|
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 ??
|
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
|
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
|
Re: Hp 400D serial number decoder
I have been told that the "16" part means 16 years since 1960 so about 1976.
regards
|
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
|
Re: Boonton 25A Power Meter Calibrator “error.”
You can use 478A Opt.: h75 / h76 . They starts @1Mhz to 1GHz …? 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 29 Aug 2022, at 23:18, Steve J. Noll, WA6EJO <sjnoll@...> wrote:
? Recently someone has been selling brand new Boonton 25A Power Meter Calibrators on eBay at a great price. I picked one up to check my HP 478A mounts and 431C and 432A meters. I find a -5 dB error on all settings! The problem turns out to be that the 25A output (0-100 mW) is at 1 MHz. The 478A mounts are only rated down to 10 MHz and are seriously inaccurate below that.
|
Boonton 25A Power Meter Calibrator “error.”
Recently someone has been selling brand new Boonton 25A Power Meter Calibrators on eBay at a great price. I picked one up to check my HP 478A mounts and 431C and 432A meters. I find a -5 dB error on all settings! The problem turns out to be that the 25A output (0-100 mW) is at 1 MHz. The 478A mounts are only rated down to 10 MHz and are seriously inaccurate below that.
|
-------- Original message --------
From: "Dave ." <ktx85@...>
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 --------
From: Dave Wise <david_wise@...>
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@...?
|
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...
toggle quoted message
Show quoted text
-------- Original message --------
From: Dave Wise <david_wise@...>
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 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
?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]>
On Behalf Of Dave . via groups.io
Sent: Monday, August 29, 2022 3:44 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Hp8640b
?
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@...?
|
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-8753E Power Cycles at Start Up
Thanks Dan; this problem is happening on an 8753B and an 8753E with old capacitors. What you experienced is exactly why I don't want to replace the capacitors without a reason. The last thing I need is a second fault. We suspect something like what you describe but cannot figure what would trip it intermittently. I just heated the protection circuit then (gently) sprayed it with freeze spray. I also gently moved the 10/220 switch in case it was intermittent.? It is difficult when I cannot get it to quit again. Peter
Re: Power Supply for 8753E
Peter:
Take a look at the + and - 15V supplies. If the filter cap there draws too much peak current during cycle peaks, the current limit shuts down the supply. I found this when putting in new capacitors and the 'better one' I put in with lower ESR casued this.?
So, do check the voltage drop with a scope on the current limit resistors.....
Dan in Chandler, AZ
|
Re: HP-8753E Power Cycles at Start Up
Re: Power Supply for 8753E
Peter:
Take a look at the + and - 15V supplies. If the filter cap there draws too much peak current during cycle peaks, the current limit shuts down the supply. I found this when putting in new capacitors and the 'better one' I put in with lower ESR casued this.?
So, do check the voltage drop with a scope on the current limit resistors.....
Dan in Chandler, AZ
|
Re: HP-8753E Power Cycles at Start Up
Peter:
After putting in a new SMPS (Newer SMPS), I have had no failures. I would like to repair the SMPS I pulled but it has not failed yet. This is why I think its a current sense problem.
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On Aug 29, 2022, at 4:56 PM, peter bunge <bunge.pjp@...> wrote:
? Rich, Mine are all Sprague and the more I test the?less I think they?are the?problem,?but.....? I should test one. Right now it is running rock solid. Has your's failed again? You said you had eliminated A8 as the problem? I have seen dipped tantalums short but they stay shorted. Peter On Mon, Aug 29, 2022 at 4:38 PM Rich Miller via <av8torrich= [email protected]> wrote: Peter:
While I cannot answer your question directly, the capacitor's in mine are Nippon’s. I have seen those last forever without fault. They were sparing no expense in this department when making the supply.?
Off the top of my head, I can’t think of anything I have seen inside this supply that would short intermittently and then recover.?
I had to leave the office, so I am not in front of the supply any longer.?
|
Jeremy Nichols
Dr. David Kirkby, Kirkby Microwave Ltd
Brian
Patricio A. Greco
Steve J. Noll, WA6EJO
