Hi,
I have an 8592L that has a level discrepancy between high and low bands ... of around 16dB, its the high band that is measuring flat, but low. ... it's not the mixer, that has been swapped for a known worker with exactly the same result (+- 0.5dB) ...? the amplitude, frequency and YTF cals complete without issue ... where to look next?
I bought this with a blown mixer, the upper range was down, the lower range was dead.?? Swapping the mixer for a known good one has restored the low range to full function, but the upper range still has the same low level ...
Ideas?
-- Best regards,
Robin Szemeti
Redpoint Consulting Limited
E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371
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Re: Re-capping an HP-130 Scopes
I learned allot from his vids.? He does have 8k+ patreaons so I figure he is making at least 20k+ plus a month so he must be doing something right.
He manages to sell his? Cap tester quite well.? I have built is but it is the one thing I rarely use as I figured out 99.9% of all waxies/paper are bad and there is no sense in even testing them or even keeping any of them.
I did find a few dud mica domino caps with it but that was from a plie of 200+ NOS I acquired.??
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On Thu, Oct 28, 2021 at 06:42 PM, Dave_G0WBX wrote:
By the sound of it, non unlike some of the early Tek 465 'scope fans, but probably physically very different.
As it happens, some HP 8620 series were equipped with the very same Siemens fan motor that Tek used in their 465-family of 'scopes. A lot has been written about their behaviour and overhaul, see Tekscopes groups.io. Raymond
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Hi.
Anyone have any hard won experience as to how best to tackle the removal of the cooling fan from a HP8620C sweeper mainframe?
The fan in mine, is running slow (so the instrument, and especially the plug ins, "run rather warm.") It is also making "grumbling bearing" sounds, so I'd like to remove it for overhaul (clean and lube, as I've done for many others) or replace it with a more modern alternative.
I am aware it is an early DC driven device, with external motor position sensor and drivers, plus it's speed is governed by a temperature sensor somewhere.
By the sound of it, non unlike some of the early Tek 465 'scope fans, but probably physically very different.
I've a "user" manual so far, but that just talks about removing/cleaning/replacing the mesh air filter.
Any advice at this stage welcome.
Regards to All.
Dave B
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Re: Re-capping an HP-130 Scopes
I’m not a fan.? His assured spew of misinformation rubs me the wrong way.
?
Dave Wise
?
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From: [email protected] [mailto:[email protected]]
On Behalf Of Roy J. Tellason, Sr. via groups.io
Sent: Thursday, October 28, 2021 9:06 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Re-capping an HP-130 Scopes
?
On Wednesday 27 October 2021 10:58:33 pm Glen Slick wrote:
> On Wed, Oct 27, 2021 at 7:53 PM Jim Ford <james.ford@...> wrote:
> This might have been the video which was relevant to capacitor
> discussion in this thread:
>
> Are Your Capacitors Installed Backwards? Build this and find out
>
Wow, talk about over-complicating things...
You don't need a scope to do this test. Just a wire plugged into any handy audio amplifier will do. One way will get you more hum out of the speaker than the other. An RCA jack allows the use of any handy audio patch cable and it's way cheaper than a BNC.
If you do want to build a gizmo, you don't need 3 ICs, either, just a pair of transistors in an astable multivibrator circuit. Put the LEDs in line with the collector of each transistor, and when that one turns on that transistor's collector is going toward
ground. If I were going to build something like that a bit of perf board would do, no need to make a circuit board, no surface mount parts either.
He mentions the "CD" prefix as being more tolerant of higher power supply voltages than other brands. If he'd gone with the original 4066 rather than the 74HC4066, they can handle power supply voltages of up to 15V no problem.
He also mentions wanting longevity in terms of operation, but uses a bipolar 555 rather than the CMOS 7555.
Not much of a fan of that channel, I guess...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
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Re: Re-capping an HP-130 Scopes
On Wednesday 27 October 2021 10:58:33 pm Glen Slick wrote: On Wed, Oct 27, 2021 at 7:53 PM Jim Ford <james.ford@...> wrote:
This might have been the video which was relevant to capacitor
discussion in this thread:
Are Your Capacitors Installed Backwards? Build this and find out
Wow, talk about over-complicating things... You don't need a scope to do this test. Just a wire plugged into any handy audio amplifier will do. One way will get you more hum out of the speaker than the other. An RCA jack allows the use of any handy audio patch cable and it's way cheaper than a BNC. If you do want to build a gizmo, you don't need 3 ICs, either, just a pair of transistors in an astable multivibrator circuit. Put the LEDs in line with the collector of each transistor, and when that one turns on that transistor's collector is going toward ground. If I were going to build something like that a bit of perf board would do, no need to make a circuit board, no surface mount parts either. He mentions the "CD" prefix as being more tolerant of higher power supply voltages than other brands. If he'd gone with the original 4066 rather than the 74HC4066, they can handle power supply voltages of up to 15V no problem. He also mentions wanting longevity in terms of operation, but uses a bipolar 555 rather than the CMOS 7555. Not much of a fan of that channel, I guess... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: OT: NI GPIB-USB-HS+ repair question
<>
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of nigel adams via groups.io Sent: 28 October 2021 15:04 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question Please can you describe how you rewrote the memory chip and where did you find the code and routine to perform it. -----Original Message----- From: [email protected] < [email protected]> On Behalf Of David C. Partridge Sent: 28 October 2021 14:00 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question You have to pry it open with a metal spudger. Good luck with it ... I'd be very interested to know what the problem is. I managed to fix a GPIB-USB-HS (the older version) by re-writing its memory IC. David -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Tom B Sent: 28 October 2021 12:57 To: [email protected]Subject: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question Hello All, I have a National Instruments GPIB-USB-HS+ adapter that appears to be dead. It does not respond at all when plugged into a USB port. What I need to know is how to open it up. I took out the two visible screws but would not come apart. There do not appear to be any additional screws under the labels. Could someone tell me how to open this device without damaging it? Tom Bryan N3AJA
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Re: Looking to buy HP6268B 40V 30A Power Supply
Alwyn
I use my 6271B all the time with My GRC 106 Military transceiver. Puts out maybe 350 W with two 350Z tubes.
But the GRC is so loud (fan) that I would not notice any PS noise.
Wally
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Re: OT: NI GPIB-USB-HS+ repair question
Please can you describe how you rewrote the memory chip and where did you find the code and routine to perform it.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of David C. Partridge Sent: 28 October 2021 14:00 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question You have to pry it open with a metal spudger. Good luck with it ... I'd be very interested to know what the problem is. I managed to fix a GPIB-USB-HS (the older version) by re-writing its memory IC. David -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Tom B Sent: 28 October 2021 12:57 To: [email protected]Subject: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question Hello All, I have a National Instruments GPIB-USB-HS+ adapter that appears to be dead. It does not respond at all when plugged into a USB port. What I need to know is how to open it up. I took out the two visible screws but would not come apart. There do not appear to be any additional screws under the labels. Could someone tell me how to open this device without damaging it? Tom Bryan N3AJA
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Re: Looking to buy HP6268B 40V 30A Power Supply
Dear Wally,
I have the 60V version, 6274B. Under J3E syllabic loading the noises from the mains transformer were loud and a little worrying, so I decided not to use it for transmitter powering.
Perhaps the experts on here could comment whether such use is likely to cause problems.
Other than that, the Rifa capacitors went up with a sizzle on 240V switch-on after a couple of years unused. Replaced those with more generously voltage rated modern alternatives and has worked well since.
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.
SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________
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Re: OT: NI GPIB-USB-HS+ repair question
You have to pry it open with a metal spudger.
Good luck with it ... I'd be very interested to know what the problem is. I managed to fix a GPIB-USB-HS (the older version) by re-writing its memory IC.
David
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Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Tom B Sent: 28 October 2021 12:57 To: [email protected]Subject: [HP-Agilent-Keysight-equipment] OT: NI GPIB-USB-HS+ repair question Hello All, I have a National Instruments GPIB-USB-HS+ adapter that appears to be dead. It does not respond at all when plugged into a USB port. What I need to know is how to open it up. I took out the two visible screws but would not come apart. There do not appear to be any additional screws under the labels. Could someone tell me how to open this device without damaging it? Tom Bryan N3AJA
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Re: Looking to buy HP6268B 40V 30A Power Supply
On Wed, Oct 27, 2021 at 12:36 PM, kc0wox Leeper wrote: Where are you located? I may have one but I'm near Denver and won't ship it.
If you are close enough I'll check on it.
Leonard Would have to ship to Miami FL. I know these can be a bear to pack and ship. Thank you.
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OT: NI GPIB-USB-HS+ repair question
Hello All,
I have a National Instruments GPIB-USB-HS+ adapter that appears to be dead.? It does not respond at all when plugged into a USB port.?? What I need to know is how to open it up.? I took out the two visible screws but would not come apart.? There do not appear to be any additional screws under the labels.? Could someone tell me how to open this device without damaging it?
Tom Bryan
N3AJA
|
Re: Looking to buy HP6268B 40V 30A Power Supply
On Wed, Oct 27, 2021 at 02:59 PM, Wallace Gasiewicz wrote: I bought the PS because I was sick and tired of dealing with birdies on SMPS
PS. This thing has no birdies. (Maybe the humming scares them?)
A really nice PS.
Wally KC9INK There you go, just another -very- good reason to stay with a good old linear PS. I have enough birdies already just dealing with the Ethernet cables and routers, don't need any more :-)
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Re: HP54720D Service manual
Hello Dave,
yes shure I'm searching the Circuit sheet plan. I found out that the Resistors (22Ohm) positions 14,15 are interrupted also the Transistor (2SC3866) position 50 is short and the Z-Diode position 57 is short. What I would like to know is the Z-Diode value? I guess that is a 6V2 or 7V1 Z-Diode - I should use a crystal-ball for this information. I've never a power-supply like this where is no schematic circuit plan.
73 de OE1DOA
Volker
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X-rays don't happen at such low voltages. The blue glow, if on the envelope, is fluorescence caused by electron bombardment. If you get a glow that is inter-electrode, it is ionized gas. -Chuck Harris On Wed, 27 Oct 2021 20:15:24 -0700 "Richard Knoppow" <dickburk@...> wrote: ?? Some tubes like the ones you mentioned, have a deep blue glow
on the inside of the envelope due to x-ray bombardment. This is
different than a gas glow, which is inside the tube, usually
between the plate and heater. This is usually a violet glow. This
is from gas that has either evolved from the elements or has
gotten in due to a leak. If a tube glows brightly its not going
to last long.
On 10/27/2021 5:24 PM, Mark Bielman wrote:
Most power amp output tubes (6AQ5, 6L6, EL34, etc) will glow a
beautiful blue.
Suspect the EL86 would as well.
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Some tubes like the ones you mentioned, have a deep blue glow on the inside of the envelope due to x-ray bombardment. This is different than a gas glow, which is inside the tube, usually between the plate and heater. This is usually a violet glow. This is from gas that has either evolved from the elements or has gotten in due to a leak. If a tube glows brightly its not going to last long.
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Show quoted text
On 10/27/2021 5:24 PM, Mark Bielman wrote: Most power amp output tubes (6AQ5, 6L6, EL34, etc) will glow a beautiful blue.
Suspect the EL86 would as well.
--
Richard Knoppow
dickburk@...
WB6KBL
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Re: Re-capping an HP-130 Scopes
On Wed, Oct 27, 2021 at 7:53 PM Jim Ford <james.ford@...> wrote:
Thanks, Glen.
I've missed the last few days due to exceeding my email storage limit at my ISP. Friends sending me too many 10-15 MB videos!
Jim
This might have been the video which was relevant to capacitor discussion in this thread: Are Your Capacitors Installed Backwards? Build this and find out
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Re: Re-capping an HP-130 Scopes
On 2021-10-27 10:40 p.m., Glen Slick wrote: On Wed, Oct 27, 2021, 7:31 PM Jim Ford <james.ford@... <mailto:james.ford@...>> wrote:
Hmmm... could you please direct me to Mr C?? I couldn't find him
online; my google-fu must be rusty.
Mr Carlson's Lab
<> +1 to Mr C. I get a lot of value from his streams for just $2 a month to Patreon. --Toby
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Re: Re-capping an HP-130 Scopes
Thanks, Glen.
I've missed the last few days due to exceeding my email storage limit at my ISP.? Friends sending me too many 10-15 MB videos!
Jim
------ Original Message ------
Sent: 10/27/2021 9:41:03 PM
Subject: Re: [HP-Agilent-Keysight-equipment] Re-capping an HP-130 Scopes
The outside foil of condensers is
usually connected to ground for shielding. If this is ignored in
the IF section of some receivers, oscillations and instability
can be a problem. In a scope or audio amplifier, the result is
likely to be hum or strange signals that come from nowhere.
??? Bruce Gentry, KA2IVY
On 10/27/21 20:31, Jim Ford wrote:
Hmmm... could you please direct me to Mr C?? I couldn't find
him online; my google-fu must be rusty.
And, what does the foil side of a capacitor sound like??
Versus the other side?? I'd have to try that, although I don't
own a vacuum tube guitar or bass amp (not yet, anyway).
Thanks.
Jim Ford
------ Original Message ------
Sent: 10/27/2021 4:02:55 PM
Subject: Re: [HP-Agilent-Keysight-equipment] Re-capping an
HP-130 Scopes
Yep been a Mr C fan for a while.? He designed a neat little
rig that checks for foil side of a cap.? I think my second
build ever.? Works great.? I even took apart a few spare
modern caps to see if the the Mr C?SIFT works and it does.
The old 'Amp' test is one that works as well.? Plug the cap
into a guitar amp crank up the volume and you can hear the
foil side.
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David C. Partridge