On Tue, Oct 26, 2021 at 01:49 AM, Richard Merifield wrote:
Can someone confirm that the voltages on the schematic are DC voltages ? At the base of R27/R28 I see about 290V DC and not 215V as per the schematic ? I Also do not see a 30V drop across L6 (245V to 215V), in fact I see about a 6V increase. Also the resistance across L6 measures 226 Ohms which seems ok ??
Yes, those are all DC voltages. First, are you SURE that the manual you are using is correct for YOUR 200CD. Check the serial prefix on the serial number plate and compare it to what's listed on the title page of your manual. If they don't match, the voltages may not apply. If you don't have much current draw from the rest of the circuit, it's conceivable that reduced ripple in C13B&C, compared to C13A, might make the averaged DC measure higher across C13B&C. You could compare how much ripple you have across C13A and C13B&C; just switch your DVM to AC and measure across each one. To start, I'd measure directly across each of those caps, rather than from ground, and check R40, to make sure it's still 10 kOhms. It's odd that HP did not ground the neg side of C13, and I'm sure they did it for a good reason, but it's possible that R40 got messed up by the shorted 5AR4..
|
Re: Looking to buy HP6268B 40V 30A Power Supply
The 6268B (and similar models) holds up well in adverse conditions, and many pallets full of them have been sent to our military in Irag and Afghanistan for those "wars". I still see requests for them on want lists.
I have a few of them here. The problem is, they weigh a ton and are a royal PITA to pack and ship.
|
Re: Looking to buy HP6268B 40V 30A Power Supply
Bonjour à tous
We manufactured transformers since 1970s, and did not suffer magnetosstriction noise, as the lamination was secured tightly and usually vacuum varnish impregnated.
I have fixed loud hum in other HP linear power supplies, like 6114A and 6115a.
the "transformer hum" was caused by yellow Mylar 0.47 uf AC capacitors across the windings ( probably at primary side) used perhaps to reduce electrical noise.
I replaced them with new caps at a higher voltage rating. In the process I tightened the mounting screws in each lamination stack. My HP supplies are now quiet. The caps had loostened over the decades and became electrostatic speakers!
I am not familiar with the HP 6268B, but from the same era. I would check for such caps before blaming magnetostrepiction!
Bon courage
Jon
|
Re: Looking to buy HP6268B 40V 30A Power Supply
Starting to look for the HP6268B power supply, no hurry. Could be a fixer upper as long as cosmetics are decent. ? It would be worth looking at the 6674A too.? The standard model is 60 V, 35 A, but there are options for 70 V 30 A (quite rare), as well as options for voyages lower than 60 V, but currents higher than 35 A. Those are switch-mode, but very heavy. They only run from 240 V or thereabouts power supplies - you can't use them on 120 V. There is no IEC connector - the mains has to e hard-wiresd in.
Dave
|
HP 3245A Universal Source
--
Members
I am a new member, and I have a HP 3245A Universal Source,? I purchased this some years ago, and for a while it worked well. Eventually the IEC power input Socket/Filter broke down, with the attendant nasty smell and leakage - this was duly replaced, and the unit continued for some time to work just fine. My Model is the one with a single standard output ,and a second X 10 output. This latter facility , with its separate PCB has suffered a failure of? electrolytic caps which in turn caused some burning to the PCB. I would like to obtain a replacement (plug in) PCB for this item which is an 88809F Rev.A 03245-66503. Any reasonable offer would be considered, or any suggestions as to a possible source would be useful. It still works with the faulty PCB removed , but the x 10 facility would be good to have back.?
Many thanks
Roy
|
I’m sorry I can’t assist but my 200CDs and all my documents are home and I’m not.?
Jeremy?
On Tue, Oct 26, 2021 at 7:04 AM nigel adams via <bristol.rell6l= [email protected]> wrote: 120Hz…, sounds like that is PSU (double mains freq, assuming 60Hz) rather than actual output… ? ? Thanks Morris.?
The 200CD is only producing a rather odd shaped wave of perhaps 200mv and random frequency somewhere < 120hz. It responds slightly to the amplitude dial but not to the frequency dial. All tubes heat up but I do not see any glow on the bulbs at all.
I am just stepping through the circuit 1 component at a time. At present I have pulled R50 and R51 pots. R51 is ok, R50 only measures 33k and is very scratchy so I will replace both. Whn back in place I will measure the volages across R27/28. R40 measures 3.1k.
I don't know why but I suspect this side (i.e. globe side) of the circuit hence my query about T1 & T2. Ohh well, I was looking for a challenging project :) for a beginner.
Would love to know what other 200CD owners measure for the transformer outputs, unfortunately there is nothing on the schematic which I find odd ?
Regards
Richard?
|
Re: Looking to buy HP6268B 40V 30A Power Supply
Thanks for the confirmation of the humming described by some sellers being normal.
Sounded strange that HP would use regular transformers that would start to hum over time.
Now its clear its more like a feature.
|
Re: Looking to buy HP6268B 40V 30A Power Supply
On Mon, Oct 25, 2021 at 05:36 PM, Roy Thistle wrote: My question/curiosity... would be why?
I mean it's okay if you fancy one... say, just to hold the basement floor
down.
But assuming you want one to do something... why one of those? I will need to test 12V and 24V equipment up to 20Amps, so the 40V 30Amp model seemed to fit the bill. And HP being HP, why not. Do you have another suggestion? Thanks.
|
120Hz…, sounds like that is PSU (double mains freq, assuming 60Hz) rather than actual output… ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Richard Merifield
Sent: 26 October 2021 11:49
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP200CD oscillator? Thanks Morris.?
The 200CD is only producing a rather odd shaped wave of perhaps 200mv and random frequency somewhere < 120hz. It responds slightly to the amplitude dial but not to the frequency dial. All tubes heat up but I do not see any glow on the bulbs at all.
I am just stepping through the circuit 1 component at a time. At present I have pulled R50 and R51 pots. R51 is ok, R50 only measures 33k and is very scratchy so I will replace both. Whn back in place I will measure the volages across R27/28. R40 measures 3.1k.
I don't know why but I suspect this side (i.e. globe side) of the circuit hence my query about T1 & T2. Ohh well, I was looking for a challenging project :) for a beginner.
Would love to know what other 200CD owners measure for the transformer outputs, unfortunately there is nothing on the schematic which I find odd ?
Regards
Richard?
|
Thanks Morris.?
The 200CD is only producing a rather odd shaped wave of perhaps 200mv and random frequency somewhere < 120hz. It responds slightly to the amplitude dial but not to the frequency dial. All tubes heat up but I do not see any glow on the bulbs at all.
I am just stepping through the circuit 1 component at a time. At present I have pulled R50 and R51 pots. R51 is ok, R50 only measures 33k and is very scratchy so I will replace both. Whn back in place I will measure the volages across R27/28. R40 measures 3.1k.
I don't know why but I suspect this side (i.e. globe side) of the circuit hence my query about T1 & T2. Ohh well, I was looking for a challenging project :) for a beginner.
Would love to know what other 200CD owners measure for the transformer outputs, unfortunately there is nothing on the schematic which I find odd ?
Regards
Richard?
|
Yes, the voltages on the schematic are DC using a voltmeter with a high input resistance quoted on the schematic as 122 megohms. The voltage using a modern DMM with an input resistance of 10 megohms or so should be pretty similar.? Is the 200CD producing any output and does this vary with the coarse frequency range switch? Assuming the mains voltage is correct, the higher voltage at the junction of R27/28 and reduced voltage drop across L6 suggests no current draw by the oscillator circuitry. You could check that by measuring the voltages across R27 and R28 which should be about 30 volts each. If it is much lower than that or even zero you should check all the tubes by substitution if possible. Also check R40.
The output voltage into 600 ohms at the maximum output setting should be 11.5 volts AC.
Good luck!
Morris
|
Sorry for the multiple posts.
Does anyone know what voltages should be seen for the secondaries of transformers T1 & T2 ??
Regards
Richard
|
Re: Agilent/Keysigh ESG series CLIP
Hi XU and Eman ? Thank you Eman for reminding me that Xu makes the excellent replacement LCD displays? for HP equipment and has been a member of this group for a time ? But the copy right issue keeps rising its head and just confuses all that do not have the back ground to the hard work that went into sorting it out ? Best regards ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Orin Eman
Sent: 26 October 2021 08:24
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent/Keysigh ESG series CLIP ? Xu is hardly new to HP... He's been around here quite a while and?makes the NewScope LCD displays ?:) ? On Tue, Oct 26, 2021 at 12:10 AM Paul Bicknell <admin@...> wrote: Dear Xu ? I assume you are new to this site and specifically HP ? ?
|
Re: Does anyone have an Agilent 16452A Liquid Test Fixture?
On Tue, 26 Oct 2021 at 02:21, Jim Allyn - N7JA < jim@...> wrote: On Sat, Oct 23, 2021 at 05:03 PM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:
There’s a document from NPL that discourages the use of the term “dielectric constant”, since it is not a constant, but as you say, varies with temperature, pressure etc. You can’t have a variable constant! The two words are mutually exclusive.?
The correct term to use is permittivity, or relative permittivity.
A search of the web site of the National Institute of Standards And Technology turns up 34718 documents that use the term "dielectric constant", but only 26531 documents that use "relative permittivity", and only 1016 instances of "permittivity."
"The United States and Great Britain are two countries separated by a common language."
The term "dielectric constant" is widely used in the UK, so it's not just the USA which uses it. However, if you think about it logically
* Pi is a mathematical constant (3.14159..).
* c is a physical constant (299792458? m/s, which is approximately 3 x 10^8 m/s)
* something that changes can not be a constant.
Science and engineering advances, and just because we have always done it one way, does not mean we should continue to do it that way. NPL's argument for discouraging the use of the term dielectric constant is to discourage people from thinking they are measuring a constant.
If you accept that relative permittivity is a better term, you can then, when appropriate, mention it is actually a complex number. The relative permittivity Er of a material is a complex number, normally written with a dash and double-dash like
Er = Er' - j Er''
where the Er'' is the loss term
? Just because
* you Americans have used the term "dielectric constant" for years * I myself have used the term "dielectric constant" for use * many Brits have used the term for years
does not mean we should continue to use such a term, when someone points out that it is not a constant but a variable.
Feel free to continue to call this variable a constant if you wish - many Brits will no doubt do it too. But this particular British person is not a stick in the mud.
Dave G8WRB
|
Re: Agilent/Keysigh ESG series CLIP
On my best knowledge, "digital"? version of this CLIP never existed. Ony paper in the past but not today.? Milan
Xu is hardly new to HP...
He's been around here quite a while and?makes the NewScope LCD displays ?:) On Tue, Oct 26, 2021 at 12:10 AM Paul Bicknell < admin@...> wrote: Dear Xu ? I assume you are new to this site and specifically HP ?
|
Re: Agilent/Keysigh ESG series CLIP
Xu is hardly new to HP...
He's been around here quite a while and?makes the NewScope LCD displays ?:)
On Tue, Oct 26, 2021 at 12:10 AM Paul Bicknell < admin@...> wrote: Dear Xu ? I assume you are new to this site and specifically HP ?
|
Re: Agilent/Keysigh ESG series CLIP
Thank you Paul for clearing this up! BR, Milan
On Tue, 26 Oct 2021, 09:20 Paul Bicknell, < admin@...> wrote: Hi Milan? Bruce is correct? we went through this all over 15 years ago
With several of us talking to the HP offices? all over the would? I personally spoke to HP UK on the subject
So there is no problems with what we are presently doing also HP did come to us for help with providing the manuals they were missing in PDF format
Regards Paul
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Bruce
Sent: 26 October 2021 03:14
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent/Keysigh ESG series CLIP
Do NOT worry -
I believe HP has issued a blanket permission on most ot their CLIPS.
Chers!
Quoting Milan Vasic <vasa1958@...>:
> OK, sorry for publishing this! Please forget all my previous posts.
> Files will go with me...
> Milan
>
> On Tue, Oct 26, 2021 at 12:53 AM Xu Wang via <simmconn=
> [email protected]> wrote:
>
>> With all the confidential markings on the schematic and such, it’s
>> best to have the manual scanned and distributed by someone who has a
>> license to do so. I’m sure some people in this group have the license
>> to distribute manuals for discontinued/obsolete HP/A/K test
>> equipment. Scanning a pdf for personal or organizational backup is
>> one thing, making it available to the public would be a different matter, for profit or not.
>> By the way, if we see missing line segments on the scanned
>> schematics, more than likely they are not there to begin with. It has
>> to do with the EDA tool that HP used back in the day. I’ve seen
>> original CLIPs missing segments or sometimes entire symbols.
>>
>> -Xu
>>
>>
>>
>
>
>
|
Re: Agilent/Keysigh ESG series CLIP
Hi Milan Bruce is correct we went through this all over 15 years ago
With several of us talking to the HP offices all over the would I personally spoke to HP UK on the subject
So there is no problems with what we are presently doing also HP did come to us for help with providing the manuals they were missing in PDF format
Regards Paul
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Bruce Sent: 26 October 2021 03:14 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Agilent/Keysigh ESG series CLIP Do NOT worry - I believe HP has issued a blanket permission on most ot their CLIPS. Chers! Quoting Milan Vasic <vasa1958@...>: OK, sorry for publishing this! Please forget all my previous posts.
Files will go with me...
Milan
On Tue, Oct 26, 2021 at 12:53 AM Xu Wang via groups.io <simmconn=
[email protected]> wrote:
With all the confidential markings on the schematic and such, it’s
best to have the manual scanned and distributed by someone who has a
license to do so. I’m sure some people in this group have the license
to distribute manuals for discontinued/obsolete HP/A/K test
equipment. Scanning a pdf for personal or organizational backup is
one thing, making it available to the public would be a different matter, for profit or not.
By the way, if we see missing line segments on the scanned
schematics, more than likely they are not there to begin with. It has
to do with the EDA tool that HP used back in the day. I’ve seen
original CLIPs missing segments or sometimes entire symbols.
-Xu
|
Re: Agilent/Keysigh ESG series CLIP
Dear Xu ? I assume you are new to this site and specifically HP ? The reason I say this is that copy right regarding HP equipment documentation was all sorted out approximately 15 years ago So much so that HP then asked the members of this present site for manuals in PDF format that they were missing ( this group was ?hosted by a different provider at the time ) Also HP direct their customers to Dave at ARTEK for documentation to support HP / Agilent equipment ????So all is OK to copy Scan and distribute ? Regards Paul ? ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Xu Wang via groups.io
Sent: 25 October 2021 23:53
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent/Keysigh ESG series CLIP ? With all the confidential markings on the schematic and such, it’s best to have the manual scanned and distributed by someone who has a license to do so. I’m sure some people in this group have the license to distribute manuals for discontinued/obsolete HP/A/K test equipment. Scanning a pdf for personal or organizational backup is one thing, making it available to the public would be a different matter, for profit or not.
By the way, if we see missing line segments on the scanned schematics, more than likely they are not there to begin with. It has to do with the EDA tool that HP used back in the day. I’ve seen original CLIPs missing segments or sometimes entire symbols.
-Xu
|
OK, I am still working away on this restoration. I have the new rectiier tube in place and now wanted to start probing some voltages.
Can someone confirm that the voltages on the schematic are DC voltages ? At the base of R27/R28 I see about 290V DC and not 215V as per the schematic ? I Also do not see a 30V drop across L6 (245V to 215V), in fact I see about a 6V increase. Also the resistance across L6 measures 226 Ohms which seems ok ??
Richard
|
Precaud
Froggie the Gremlin
Dr. David Kirkby, Kirkby Microwave Ltd
Jeremy Nichols
Paul Bicknell