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Re: HP 8640B - internal counter suddenly got crazy
Francesco, we cross posted.
If not EECL, what? The most intriguing behavior is "External counter input works OK in the 0-10Mhz range, but doubles the reading in the 10-512Mhz range (BUT not if signal is coming from output REF (rear panel) !!" I'll double check the band switch wipers... they seem in place and none found floating inside the instrument.. |
Re: HP 8640B - internal counter suddenly got crazy
On Wed, Nov 24, 2021 at 9:55 AM Emanuele Girlando via groups.io
<emanuele_girlando@...> wrote: when that IC dies, usually the counter doesn't show any count when switched to the high frequency input. I've done a similar replacement as described in the N2GX article, but that circuit didn't work for me, I've had much better success by using a proper transistor based level converter instead of the simple diode level shifter he used. I've reported my changes to its schematic on this group years ago (it was 2014 or 2015 afair). I don't recall much of the details now, my 8640B's counter is working fine since then, even better than with the original prescaler. Frank IZ8DWF |
Re: HP 8640B - internal counter suddenly got crazy
I've received the manual.
I am going to go through the counter tests to isolate the fault. I suspected the unobtainable? EECL front end chip. Just in case, does anybody have experience replacing it with Motorola MC100EL31D (or with MC10EL31DG) as described in a 1999 article from n2gx I've found on the Internet ? Thx. Emanuele. |
Re: HP 8640B - internal counter suddenly got crazy
I don't think it's the EECL prescaler or any other EECL in the counter
assembly, it usually makes the high frequency input dead. However I've succesfully replaced the EECL prescaler with a modern ECL IC, that was more than 5 years ago, but it should be found in the groups archives. In these cases, the first thing to do is get the correct schematic and manual for your 8640B serial prefix. This instrument went through a lot of different revisions and schematics can have large differences between the revisions. Once you get the correct schematic, the usual method is following the troubleshooting procedures. You need some good test equipment though. Frank IZ8DWF On Wed, Nov 24, 2021 at 9:11 AM george edmonds via groups.io <G6HIG@...> wrote:
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Re: BASIC on the HP 3396B Integrator II ?
BTW, there was a discussion going on on the ChromForum that points out that Peak96 obviously needs a special cable to run properly:
pinout Peak 96 Data Transfer Cable Configuration: .....DB 15 Connector..........DB 9 Connector ............1................................... 1 ............2....................................3 NC........3.................................... SH........4....................................4.....SH SH........5....................................7.....SH NC........6....................................8.....SH NC........7.................................... NC........8.................................... ............9...................................5 NC........10.................................. NC........11..................................6.....NC NC........12 ................................9.....NC NC........13.................................. ............14.................................2 NC........15................................. NC = No Connection SH = Pins shorted together Chris |
Re: BASIC on the HP 3396B Integrator II ?
...another approach would be to look at the description of the instruments and SW that are supposed to run with the 3396B, for example the 5890 GC documentation. I added a description that details out the RS232 configuration required for the 5890 GC to connect to UniChrom.
Chris |
Re: BASIC on the HP 3396B Integrator II ?
Hello Martin,
maybe the Agilent 3396 Series Integrator BASIC Reference Guide might help here? Please see attached. The Agilent website mentions the 3396-90335 manual as obsolete (which initially was a manual for the 3396A, as far as I know), but it might be worth a request: Chris |
Re: HP 8640B - internal counter suddenly got crazy
Bonjour I dont comprendre if it was OK and now changes or it was always that way.
Please clarify, counter indication was first OK and something changes or failed or it was always bad? The behavior of the counters depends on the option for doubler extending the highest band to 1024 MHZ. I am sure this is a moved or oxidized contact on the band switch. 8640B options and serial number manuals are available as free PDF perhaps from BAMA archive or on an HP legacy site. Bon Chance Jon |
Re: I'm old 70+, the 70K system is old; good or bad omen?
On 11/23/21 11:31 PM, Gene Silvernail wrote:
All, Disregard previous 70900A power supply capacitor statements I made. A case of head? improperly arrange on my anatomy. My apologies.Yes, it's mechanical; I did mention this a day or two ago, I guess it just went by. My mistake was starting without a schematic. The caps are packed side by side tight preventing a clean view of the big arrow. Markings, which on most electrolytics points to the neg terminal on axial packages. In these the marling points to the Positive terminal, not THE END, arranged radially… oh hell… you live and learn even over 70.Fortunately they're not difficult to remove on those boards. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育Not? a problem. How technology has changed, though.? I remember single hole electrolytics that mounted with a single nut.? Inside, I think, may have been a boric acid solution.? Of course, the tubes in that one had two digit numbers, IIRC. Harvey
On 11/23/2021 11:33 PM, Gene Silvernail
wrote:
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Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育Thanks Harvey, ? My mistakes see my other apologies. ? Regards Gene ? From: [email protected] <[email protected]> On Behalf Of Harvey White
Sent: Tuesday, November 23, 2021 8:20 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] I'm old 70+, the 70K system is old; good or bad omen? ? Many of the typical capacitors with metal cans have more than one ground lug, arranged in a circle.? The lugs are, IIRC, only for grounding and mounting stability.? On the capacitors I've seen (not the two lead ones), inside the circle formed by the case mounting ears you'll find the hot lead of the capacitor.? If you remember the dual capacitors in tube equipment, the hot leads should be inside this circle as well. One thing to note (for instance, in the 468 series scope), the case can be used as a jumper to tie grounds together.? The little adaptor plates often have ties to a common ground ring, even though the replacement capacitor only has two leads.? You may have to run a wire from ground lug to ground lug if they are not obviously visually connected. Harvey ? On 11/23/2021 11:03 PM, Gene Silvernail wrote:
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Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育All, Disregard previous 70900A power supply capacitor statements I made. A case of head? improperly arrange on my anatomy. My apologies. ? What’s is now realized…duh ? The blue caps on the PS are NOT duals but standard low ESR caps. The third lone lead on the one end is for mechanical purposes only no electrical. This would help in shake table testing for vibe specs, an assumption. ? My mistake was starting without a schematic. The caps are packed side by side tight preventing a clean view of the big arrow. Markings, which on most electrolytics points to the neg terminal on axial packages. In these the marling points to the Positive terminal, not THE END, arranged radially… oh hell… you live and learn even over 70. ? Where can a schematic for the 70900A PS board be acquired? Its not Artek. Just bought theirs and no PS data. ? Pre-thanks for all the help and again my apologies. ? From: [email protected] <[email protected]> On Behalf Of Gene Silvernail via groups.io
Sent: Tuesday, November 23, 2021 8:04 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] I'm old 70+, the 70K system is old; good or bad omen? ? Thanks Kuba, ? Yeh coming from the era of tubes I had assumed a dual cap…so much for assuming. Now that’s starting to make sense with the single component designator, but leaves the question which 2 out of the 3 leads make up the capacitor and what purpose does the third lead serve. Is it a non-electrical, mechanical only? I’m working without a schematic even though I bought the CLIP from Artek which is minus the PS board. ? Pre-Thanks ? Gene/K7QHO ? From: [email protected] <[email protected]> On Behalf Of Kuba Ober ? My assumption would be that the number of legs has not much to do with anything: it’s a single capacitor each with 3 or 4 legs. Very common in that era. I’ e got lots of contemporaneous Tektronix equipment that has the same capacitor styles. ? The double and triple electrolytics were a thing in the vacuum tube era. ? Cheers, Kuba ?
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Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育Many of the typical capacitors with metal cans have more than one
ground lug, arranged in a circle.? The lugs are, IIRC, only for
grounding and mounting stability.? On the capacitors I've seen
(not the two lead ones), inside the circle formed by the case
mounting ears you'll find the hot lead of the capacitor.? If you remember the dual capacitors in tube equipment, the hot leads should be inside this circle as well. One thing to note (for instance, in the 468 series scope), the
case can be used as a jumper to tie grounds together.? The little
adaptor plates often have ties to a common ground ring, even
though the replacement capacitor only has two leads.? You may have to run a wire from ground lug to ground lug if they are not obviously visually connected. Harvey
On 11/23/2021 11:03 PM, Gene Silvernail
wrote:
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Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育Thanks Kuba, ? Yeh coming from the era of tubes I had assumed a dual cap…so much for assuming. Now that’s starting to make sense with the single component designator, but leaves the question which 2 out of the 3 leads make up the capacitor and what purpose does the third lead serve. Is it a non-electrical, mechanical only? I’m working without a schematic even though I bought the CLIP from Artek which is minus the PS board. ? Pre-Thanks ? Gene/K7QHO ? From: [email protected] <[email protected]> On Behalf Of Kuba Ober
Sent: Tuesday, November 23, 2021 7:26 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] I'm old 70+, the 70K system is old; good or bad omen? ? My assumption would be that the number of legs has not much to do with anything: it’s a single capacitor each with 3 or 4 legs. Very common in that era. I’ e got lots of contemporaneous Tektronix equipment that has the same capacitor styles. ? The double and triple electrolytics were a thing in the vacuum tube era. ? Cheers, Kuba
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70900A Artek CLIP Manual
Working on the PS board of the 70900A and bought the CLIP from Artek. Beautifully clear images, excellent for what's there. Unfortunately, the one thing I really needed it for isn't, that being the PS board. Anyone have any idea where that would that be found? Any help is greatly appreciated.
Pre-Thanks Gene/K7QHO |
Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育My assumption would be that the number of legs has not much to do with anything: it’s a single capacitor each with 3 or 4 legs. Very common in that era. I’ e got lots of contemporaneous Tektronix equipment that has the same capacitor styles. The double and triple electrolytics were a thing in the vacuum tube era. Cheers, Kuba 23 nov. 2021 kl. 9:54 em skrev Gene Silvernail <genesilvernail@...>:
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Re: I'm old 70+, the 70K system is old; good or bad omen?
开云体育Thanks Paul, ? Just got the component location PDF on the site which provides me the PS cap numbers; also ordered the 70900A CLIP. However, looking at them I’m confused further with the 3 leads. Only 1 component number associated with a dual capacitor…huh? Hopefully the schematic will clarify this. ? Regards ? Gene ? From: [email protected] <[email protected]> On Behalf Of Paul Bicknell
Sent: Tuesday, November 23, 2021 12:56 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] I'm old 70+, the 70K system is old; good or bad omen? ? Hi Gene |