Re: 5383a counter-Need 7seg decoder IC (HP 1820-0914)
A rather rare one.? Crosses to a industry part number 9307PC (plastic package) or 9307DM (ceramic package).? Is currently stocked by Rochester Electronics but they want you to purchase a quantity of them for over $300.? I see that there is a single 9307DM on ePay if that is all that you need but is a bit pricey.
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Data sheet:
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Without digging further something like a 74LS 247 might work if the outputs meet the needs of the display.? It is pin-for-pin physically compatible with the 9307. ??Jameco Electronics appears to have them for a buck and some change.? And if you enter ¡°decoder driver¡± in their search window it will bring up several other components but you would have to compare data sheets to see if they would be suitable for the application with respect to pinout & electrical specifications.
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Greg
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Re: 8560E Second Converter
Sorry I rushed that last email.
For more relevance the second converter
I am talking about is a 5086-7957 and it is low on gain.
Dave
On 8/02/2022 1:10 pm, Dave Ireland
wrote:
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Has anyone had any joy repairing on of these.
Dave
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Has anyone had any joy repairing on of these.
Dave
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Is this supposedly a "stock" HP diode or do you suspect it has been repaired B4 with something link a 1n34 or 1n914?
Also, is there any kind of DC block in the system (that disk could be a capacitor. If no cap, why cutoff at 100K? If they are saying that because of chopped DC, then a parallel capacitor would fix that.
Any diode detector without a DC block will be acceptable.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
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Dave,
Interesting... Very simple. Were you able to easily find a replacement for
that diode? Does it look like it will be difficult to reassemble properly?
(I am thinking in its simplicity, mechanical/physical properties of
geometry, contact, fit, lengths of diode terminals, etc. will have a large
impact on results).
Also, are you able to measure its performance when repaired?
Radu.
On Mon, Feb 7, 2022 at 1:53 PM Dave Wright <davewrightsplace@...>
wrote:
See /g/HP-Agilent-Keysight-equipment/album?id=272489
My 8471A, diode is fried, (well, I did find it in a dumpster...) working
on replacement, will update results when done...
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Dave, Interesting... Very simple. Were you able to easily find a replacement for that diode? Does it look like it will be difficult to reassemble properly? (I am thinking in?its simplicity, mechanical/physical properties of geometry, contact, fit, lengths of diode terminals, etc. will have a large impact on results).? Also, are you able to measure its performance when repaired?? Radu.?
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Dave Wright <davewrightsplace@...> updated the album 8471A Internals: Disassembly of 8471A RF detector prior to diode replacement.
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Re: Cascaded amplifier for 8673D Watkins Johnson 6203-044 (HP 0955-0215 )
Hi Vladan, ? there was a problem with the amplifier, it had a variable gain, especially in low frequency, the cause: bad ground contacts by the PCB screws not tight enough. Now everything is stable, and the gain is 38dB in the middle of the band, the flatness about 1.2dB. Thanks for the information. ? -Yves ? ? No, I don't have any information about its flatness, but the numbers you give are too far off. I don't know the P1dB specification either. Given the relatively high gain, make sure you didn't test with a signal that's too strong. Also, check the return loss. That may confirm if it's defective.
Vladan
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Hi , who can share schematic and eprom dump?
thanks
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5383a counter-Need 7seg decoder IC (HP 1820-0914)
Looking for a replacement U1 IC for the 7 seg decoder in HP 5383a counter. Heres a pic of the 5383a display circuit The manual shows HP part number 1820-0914 or Fairchild 9307 or Motorola MC8307P. If anyone has 1 or 2 they would like to part with please let me know.? Otherwise looking for suggestions on whether a generic TTL 7448 or 74248 decoder could be used in its place. (Pinouts are same but still comparing the segment output drive specs) Thanks in Advance DB 
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Thank you for all your help.
I've decided to order the original part.
Istvan
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Re: Cascaded amplifier for 8673D Watkins Johnson 6203-044 (HP 0955-0215 )
No, I don't have any information about its flatness, but the numbers you give are too far off. I don't know the P1dB specification either. Given the relatively high gain, make sure you didn't test with a signal that's too strong. Also, check the return loss. That may confirm if it's defective.
Vladan
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I am seeking the schematics and troubleshooting pages for this instrument with the serial prefix 2501Axxxxx. This unit has pcbs 03312-66501 Rev. E and 03312-66502 Rev. E. The latest manual I have is for prefix range 1432Axxxxx.
Joe
KW4YW
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Re: HP 8753D Connection Adapters?
On Mon, 7 Feb 2022 at 08:08, James Sawle (MD0MDI) < james@...> wrote: Thanks everyone, I must have spent ages just looking at the ends and wondering why the leads would not connect to the unit and why I had not been supplied the connection adapters! Opps!
Rookie mistake, and thanks for the help, much appreciated.
James
I did not see the start of this thread, and don't have time to look back.
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I have had customers report problems with Chinese ones above 3 GHz, and others say they are okay - I have never measured any myself.? If I had a 6 GHz test set, and intended using at 6 GHz, I would probably be tempted to buy the Keysight ones, despite the much higher price. However, the VNA cal kit should take out the errors introduced by the adapters, but if there's a considerable loss, as some have reported to me, it will degrade your performance.
There's quite a bit of information on the 8753 here
Dave
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Re: Adjustment procedure for 355C VHF Attenuator?
is the nylon glide, but the price is quite high, along with the screws. The resistors are all obsolete, but you might find some on Ebay or other sources. I would see if some phillips head nylon screws to replace the glides.
According to the Keysight part description, the hole is 0.19" which would be a #10 screw.
I buy hardware from Fastenal, or Grainger but there are other sources.
may work, and they are much cheaper than $5.05 each from Keysight.
is another option, if you don't care about the color. 50/$7.80
Thanks for the info so far!
I have had a closer look and it seems someone has had their sticky fingers in here previously.
One screw and the 4 feet are missing, a BNC has been replaced, and one resistor had a crack at the end and the end-cap where the leg bonds to the body and just fell away. I think this may have been dropped at one point in its life probably.
I have measured all the resistors, and all but a few are way out of the 0.5% tolerane that is written on the resistor body, with the worst sitting at 10.5% high.
I also measured the microswitches and they all measure under 0.005 ohms with 4-wire measurement, so at least they seem good.
The cam action is perfect and the dial switches the microswitches properly too.
At this point, I think I don't have much to lose in replacing the resistors, I think there may have been water ingress as there was a little bit of corrosion of the aluminium inside, so maybe this has affected the resistors.
The trick is finding the correct resistor values... and a BNC connector, part number 1250-0254, and a screw and feet too... Anyone got some spare parts? :D
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Re: HP 8753D Connection Adapters?
Thanks everyone, I must have spent ages just looking at the ends and wondering why the leads would not connect to the unit and why I had not been supplied the connection adapters! Opps!
Rookie mistake, and thanks for the help, much appreciated.
James
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Given the performance required, I suspect that a garden-variety
transistor array (e.g., LM3046, etc.) might suffice electrically. I
have no idea how much room you have to work with, but if you have
sufficient space, you might be able to shoe-horn one of those more
commonly available arrays, appropriately cross-wired.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 2/6/2022 02:06, Istvan Kovacs wrote:
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Hello,
my first message to this group.
I'm looking for a cross-reference for an HP 1858-0015. It consists
of two differentially connected NPN transistor pairs in DIP-16. It
is used in limiter circuit between a local oscillator and a double
balanced mixer in my HP 3586B Selective Level Meter.
I've found two sellers on eBay but I'm trying to find a
cheaper/local source.
Thanks,
Istvan
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Re: Cascaded amplifier for 8673D Watkins Johnson 6203-044 (HP 0955-0215 )
Thanks for the answer, do you have the information for the flatness? My amp must be defective, it has 26dB of gain at 10 MHz and 30 dB at 2 GHz. ? ? 38dB gain
10 MHz - 2 GHz
VSWR 2.0 max
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Istvan,
This limiter IC was made at the HP Santa Clara division. It was also known as part number 5084-0160, but I see no useful information on the web. Maybe you can find an ECL line driver or buffer and modify the circuit.
Vladan
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Dr. David Kirkby, Kirkby Microwave Ltd
Michael A. Terrell
James Sawle (MD0MDI)