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Re: HP 8350B sweeper behaviour
On 19 Nov 2023, at 18:50, Jeff Kruth via groups.io <kmec@...> wrote:
What is interesting to me is the expectation of greater accuracy than was possible...I'm probably spoiled by these synthesised generators. When I was at school, many years ago, I build a generator myself. Certainly horrible performance, but I did not have any tools to measure that. Now I have the tools, so... But what about the noisy SA trace of the 83522A, compared to Yves's trace or the one from the older module? cheers Martin |
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Re: HP 8350B sweeper behaviour
What is interesting to me is the expectation of greater accuracy than was possible. Essentially, the display LEDs on an 8350B are part of a Voltmeter, not a FREQUENCY COUNTER. 5 MHz at 10 GHz is .05% accuracy: Pretty impressive for something designed 40+ years ago...
Non synthesized sources!
Jeff Kruth
In a message dated 11/19/2023 12:34:12 PM Eastern Standard Time, yves_tardif@... writes: ?
Martin, ? You wrote: "The microwave module is even worse, at 10GHz its off by 5MHz with no CAL as the other modules have." The frequency accuracy maybe off by 5MHz, in CW mode, the tolerance is ¡À20MHz. ? The FREQ CAL potentiometer on the front panel is only used to align a cavity oscillator for down conversion to cover a frequency band starting at 10 MHz. Your 83545A covers a range of 5.9-12.4GHz, so this FREQ CAL control will be missing. ? ? ? The DIP switch can be modified to configure certain parameters. Here is the list for each switch. Switch #2 and #3 do not show details, but for the 83540A, switch 2 is at 1, and switch#3 is at 0. ? ? De?: [email protected] <[email protected]> De la part de Martin via groups.io ? Hi Yves, ? |
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Re: HP 8350B sweeper behaviour
¿ªÔÆÌåÓýMartin, ? You wrote: "The microwave module is even worse, at 10GHz its off by 5MHz with no CAL as the other modules have." The frequency accuracy maybe off by 5MHz, in CW mode, the tolerance is ¡À20MHz. ? The FREQ CAL potentiometer on the front panel is only used to align a cavity oscillator for down conversion to cover a frequency band starting at 10 MHz. Your 83545A covers a range of 5.9-12.4GHz, so this FREQ CAL control will be missing. ? ? ? The DIP switch can be modified to configure certain parameters. Here is the list for each switch. Switch #2 and #3 do not show details, but for the 83540A, switch 2 is at 1, and switch#3 is at 0. ? ? De?: [email protected] <[email protected]> De la part de Martin via groups.io ? Hi Yves, |
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Re: HP 8350B sweeper behaviour
On 11/19/23 10:15, Chuck Harris wrote:
The other possibility is the dip switches on the pluginAt LSSM, failed DIP switches are the #2 failure that we have to deal with on half-century-old computers, second only to small electrolytic capacitors. We nearly always just replace them. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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Re: HP 8350B sweeper behaviour
Hi Yves,
here are my results. 1) HP 83522A set as yours, also about the same parameters on my SA. The trace is similar, but much noisier than yours. 2) Hp 86222B (same frequency range) plugged in with the adaptor. Same settings, peak is a bit sharper and much less noisier. But less stable too, doing significantly more wandering around. BTW, the DIP-switches were set to 10001010!! Don't know what that belongs to, but once I set it to 00000010 everything was fine. Why is this configuration modifyable at all? With the wrong setting I could get frequencies up to around 2,8GHz. The attenuator was OK only below 2GHz, above it worked in steps of 10dB (with the relay clicking). With the correct DIP setting it worked fine on all (allowed) frequencies. cheers Martin HP 83522A HP 86222B |
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Re: 8510C System Bus Address Error
Hi folks,
problem solved. Previously, I only checked the GPIB addresses of present instruments. I have now set the GPIB addresses of not-connected units (like the second source which I don't have) to 31 and the error is gone. GPIB works flawlessly. Btw, meanwhile I have also swapped the dead CMOS battery. Now the clock keeps ticking... Two more questions: 1. Upon power-up the unit comes up in factory state, i.e. in hold state. I would like it to come up sweeping. How can I change this? Setting the user preset state is not sufficient. 2. Is the low frequency behavior of the 8517A test set normal? I remember that some units have wideband bridges with no drop at low frequencies while others have couplers showing the drop at low frequencies. I'm not sure which type the 8517A is. Tom |
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Re: HP 3400A Upgrade PCBs Available
The original boards with edge connectors were nickel or gold plated, the ones I saw on ebay looked to be HASL, this could be a problem with the gold edge connector sockets, a warning from an ex-HP designer that they can get quite stuck here;
I prefer my HP TE to be original where possible, but I do have a 1976 prefix design Rev. that got modernized by HP with a 03400-66512 Rev C board from 1984. I've got quite a few 3400As, can't remember the PSUs causing much trouble, except where an incorrect manual was used by a previous repairer & Ge/Si parts got mixed up, some diodes & resistors changed for biasing, all mine are using Ge power transistors, TO-3 parts are getting pretty much obsolete these days anyway, so finding genuine parts from reputable suppliers is a problem. Wonder what people are doing with the old but still working A6 boards? Noting the large & small optical chopper assemblies were used in other HP analog meters & some DVMs. One thing I've never found is a decent readable manual for the later serial prefix of the 3400A, I tried the manual bundle from Artek, the 03400-OSM-90008 is a decent scan of the 1972 manual (marked part no. 01768 on the pages), the 1972 03400-90008 is available for free download, but I haven't checked how much it differs. But the 03400-90013 is the exact same one available by download from Agilent/Keysight, the scan quality isn't great. Has anyone got a decent scan covering the later variants? i.e. A6 with part no. 03400-66512 Rev A & C, Also I've found there was an 03400-66512 Rev D board, but the manual fails to cover that. Has anyone got a good picture of that board showing both sides? As I'm currently working on making my own version of this board. David |
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Re: HP 3400A Upgrade PCBs Available
No results from either eBay?or eBay.de. Later today, when I¡¯m more awake, I¡¯ll try Google translate and see if that helps.? Jeremy? On Sun, Nov 19, 2023 at 12:31 AM Don Brown, N3DEB <dbawatsonville@...> wrote: It is Germany. Seller chatted with me on Ebay messaging and said he will provide instructions in English. I asked for the BOM to see if anything unusual for US sourcing, which he promptly provided. |
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Re: 4195A restoration adventure*
On 18. Nov 2023, at 12:19, RubenRubio <rubenrb2019@...> wrote:
You mean inject -12 volt in the rail externally? I thought about it, but I wasn't sure if it would be safe.Thats something I do quite often, and I think its not risky if you take a lab supply and limit current to some intelligent value. More than once I had shorted caps that drew most of the current. That way I can easily identify the culprits with a thermal imager. This method also works well for shorted paths /contacts etc. cheers Martin |
Martin
Dave McGuire
factory
Jeremy Nichols