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Re: A homemade diode power sensor for HP meters

 

Hello Tobias, some information for your diode power sensor please.
Best regards.
Francesco.
G7OYO
Re: A homemade diode power sensor for HP meters

 

The output of the detector AD8318/17 is positive any idea to make it negative? Please diagram I'm one geriatric old man.
Regards.
Francesco.
G7OYO
Re: A homemade diode power sensor for HP meters

 

Thank you Dave for the imput to this post, I'm aware there is some difficulty fot the detectot part on the power head.
I hope if there someone want share is exsperience and like give some sugestion and diagram to help to build one will be apreciate.
Francesco.
G7OYO

?
?
Sent:?Sunday, May 30, 2021 at 6:47 PM
From:?"Dave McGuire" <mcguire@...>
To:?HP-Agilent-Keysight-equipment@groups.io
Subject:?Re: [HP-Agilent-Keysight-equipment] A homemade diode power sensor for HP meters
On 5/30/21 1:14 PM, Francesco wrote:
> This topic is on the dead track?? It is one very interesting topic,
> considering there is one Hi number of HP 435, 436, 437 models for a low
> price is a good opportunity for small lab and student on the RF world to
> grab one of these simple instrument for 50/100 pounds, the big problem
> the second-hand market is on the hand of surplus scavengers they sell
> the hold and rusty powerhead at Hi price.
> Way no make one at a low price and nice fun to handmade one with some
> good result making a one-hybrid system like es: detector AD8318/17 the
> chopper, and the amplifier using the 8484A diagram using the chopper FET
> circuit and the NPN Transistor amplifier.

Some people have done this. I had something very much like this
running in a bench test configuration several years ago. It worked
reasonably well, but not well enough to productize, and there were still
unresolved problems. The power sensor interface is simple, but not
quite as simple as it looks.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA




?
Re: General opinion on 180 series scopes?

 

Currently eBay is showing 1804a 4 channel plugins for around $20-50. The 1804 does 4 channels but no math. The 2 channel units have addition and the specs say when one Chanel is inverted it acts like a differential input instrument! The 1821 dual time base is spectacular. It can be set up to have a variable width time delayed window within the display which is higher intensity on the screen and thus can magnify a signal within the signal. Also, a trigger can be set within that segment and a separate external trigger can be use for the main and the delayed segment. This gets you behavior like on a digital storage scope. Imaging the ability to trigger on certain glitches during the delay time. I used to use it to pluck out separate scan lines in an NTSC composite signal. Set up a separate circuit to count pulses in the signal and feed the counter output into the secondary trigger and you could pick the scan line. This is very flexible triggering. ?Fun to use scope. I just picked up a 4 channel plug in and now have a 4 channel analog scope. ?Screen display is rock solid when you get the trigger set up. The scope is intuitive to use. Schematics available. I think it is a great beginner scope if working. It is easy to repair with all discreet components. It has a cool feature of a signal delay line so you can see a bit of the signal before the trigger fires.
Re: HP 180A and 1804A manuals ?

 

Same thing happened to me years ago. Replaced the transistor and all was well. Until it was in storage, then started up and it died the same way. I’ll have to fix it the same way, but perhaps the unused scope has marginal power supply electrolytics. ?So I’ll need to trace out the power supply on that. Thanks to the group for the transistor recommendation.
Re: Three-volume Book about Hewlett Packard South Queensferry history to be available soon

 

The reason for this timeline is that subscription is possible until June 12, 2021, then production starts.
BTW: expect to get a heavy packet: the books are not regular book size, it is 1200 pages A4!

One adjustment about my previous posting I need to make. I was not precise enough about the role Hugh Walker had in the 3721A Correlator development. Even though he has a deep insight into what is going on in this box, he was not directly involved in the design. That was done before he joined HPSQF. His babies were for example the 3710MLA and the 3745 SLMS. Just to be historically correct...

Chris


On Sat, May 29, 2021 at 09:28 PM, Larry McElhiney wrote:
FYI:

Acknowledgement

"We expect to dispatch from Scotland, UK, via AIRMAIL
on the 16 July 2021 and will email you again then
with dispatch details including your Invoice."

Larry
AC9OX
Re: A homemade diode power sensor for HP meters

 

On 5/30/21 1:14 PM, Francesco wrote:
This topic is on the dead track?? It is one very interesting topic,
considering there is one Hi number of HP 435, 436, 437 models for a low
price is a good opportunity for small lab and student on the RF world to
grab one of these simple instrument for 50/100 pounds, the big problem
the second-hand market is on the hand of surplus scavengers they sell
the hold and rusty powerhead at Hi price.
Way no make one at a low price and nice fun to handmade one with some
good result making a one-hybrid system like es: detector AD8318/17 the
chopper, and the amplifier using the 8484A diagram using the chopper FET
circuit and the NPN Transistor amplifier.
Some people have done this. I had something very much like this
running in a bench test configuration several years ago. It worked
reasonably well, but not well enough to productize, and there were still
unresolved problems. The power sensor interface is simple, but not
quite as simple as it looks.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: A homemade diode power sensor for HP meters

 

This topic is on the dead track?? It is one very interesting topic, considering there is one Hi number of HP 435, 436, 437 models for a low price is a good opportunity for small lab and student on the RF world to grab one of these simple instrument for 50/100 pounds, the big problem the second-hand market is on the hand of surplus scavengers they sell the hold and rusty powerhead at Hi price.
Way no make one at a low price and nice fun to handmade one with some good result making a one-hybrid system like es: detector AD8318/17 the chopper, and the amplifier using the 8484A diagram using the chopper FET circuit and the NPN Transistor amplifier.
If you need one power meter to make money BUY one 12.000 meters, but for hobby student and small lab the approach of Tobias whos the good one.
Re: HP 8662a 5.2V current draw

 

Attached the various power supplies and the 8662 seems to come up nicely. Its kind of a hodge podge in powering on. But the initial?100 MHz is 100 MHz. So good to see all I am fighting is the crazy dc-dc converter.?
I have the boards on the bench for the converter and its difficult to tell whats?going on. Having read the manual and what little is available online.
But no matter now I know what to focus on.
Thanks everyone.
Paul
WB8TSL
Re: HP 8662a 5.2V current draw

 

You can first try a lighter weight variable 5 V PS, say a 5-10 A bench type to juice it up part way. It won't run the full load, but you can see if anything bad happens as you bring it up, and trace shorts, etc. If you use only a high current fixed on/off one, it may be too much for anything shorted. Also, a fixed high current SMPS may deliver over 20 % beyond spec current, and may limit in various ways, from constant current, to foldback, to trip/restart and others. If you do use one, you should make sure of its limiting style.

Ed
Re: meaning of "DSA failure" in hp 3585A service manual

 

Hello Alberto,
DSA means Digital Signature Analysis. A signature analyzer (like the 5004 or 5005 series) is incredible helpful if there is a problem with the logic...
Repaired two of these recently, these are beasts and very difficult to repair. I recommend to try to perform a full calibration. The troubleshooting trees are very helpful for individual problems,? but as soon as an instrument has multiple problems, they sometimes might be misleading.
Chris


On Sun, May 30, 2021 at 01:26 PM, Alberto, IZ2EWV wrote:
Hello friends,
I'm repairing a 3585A spectrum analyzer that has problems with its local oscillator ("LOCAL OSC. UNLOCKED" on the screen).
First, I found a bad 2N3055 in the A34 LO control board, which didn't give +5V to its own circuits and to the A33 N-fractional divider.
But, even if, after this repair, something more begun to become alive in that area, I'm still going on with the LO Control (A34) Troubleshooting Tree (page 11-212 of the service manual) and I'm asking the meaning of this checkpoint: "Is the problem related to a DSA failure on another board?".
Thanks in advance to every guy who can give me the explanation of DSA, which allows me to take the appropriate answer and take the right branch of the tree!
Alberto

?Hello
Re: HP 8662a 5.2V current draw

 

Thank you everyone for sharing your insights. In the process of connecting up a pile of switchers and wires to temporarily replace the transistor eating inverter.
The smallest large 5V supply I have is 25A so should be good for a true smoke test in an hour or two.
The goal is to simply see if the rest of the unit is alive. There are no obvious shorts on any of the power busses.
Thanks again.
Paul?
WB8TSL
meaning of "DSA failure" in hp 3585A service manual

 

Hello friends,
I'm repairing a 3585A spectrum analyzer that has problems with its local oscillator ("LOCAL OSC. UNLOCKED" on the screen).
First, I found a bad 2N3055 in the A34 LO control board, which didn't give +5V to its own circuits and to the A33 N-fractional divider.
But, even if, after this repair, something more begun to become alive in that area, I'm still going on with the LO Control (A34) Troubleshooting Tree (page 11-212 of the service manual) and I'm asking the meaning of this checkpoint: "Is the problem related to a DSA failure on another board?".
Thanks in advance to every guy who can give me the explanation of DSA, which allows me to take the appropriate answer and take the right branch of the tree!
Alberto
Re: HP 8753C CAUTION: NO IF FOUND: CHECK R INPUT LEVEL

 

Hi

We have now measured the voltages both when the YTO 5086-7473 is connected and not: /g/HP-Agilent-Keysight-equipment/message/71364 and at 10 MHz:

Pin/Unconnected/Connected
1: -14,8 V; 14,6 V
2: NC
3: Ground
4: 5 V; 5 V
5: 21,2 V; see scope pictures
6: 0 V; 0 V
7: NC
8: 14, 9 V; 14,9 V
9: varies; 0 V
10: 0 V; 0 V

We also tried to run the YTO outside the NA through an extended ribbon cable, ~20 cm, but the the NA said that the R input was overloaded despite nothing was connected to it.

Is it fair to conclude that the YTO needs to be repaired or are there more tests to carry out before concluding?

Bo

HP_5086_7473_Pin5_a.jpg
HP_5086_7473_Pin5_b.jpg

Re: HP 8662a 5.2V current draw

 

P.D.:
Also, the oven draw 600 mA peak with 30-31 volt suply and the cooling fan is 140 mA (mine is 230 VAC)
Re: HP 8662a 5.2V current draw

 

Hello!

In my 8663A the peak current draws are:?~12 amps in the 5.2 rail, 0.4 A in the -40 volt rail, 2.2 A in the -10V rail and 1.83 A in the +20V.
The last three measured with a calibrated programmable linear power supply, and the 5.2 estimated and now working perfectly with a brand new meanwell brick RS-75-5, which is designed to deliver 12 amps max.

Hope this helps,?

R.
HP 53150A CLIP or Service Manual

 

Hey guys,

Any ideas if the CLIP or the Service Manual are out for these counters?

Regards,
Razvan
Re: HP 8662a 5.2V current draw

 

Hi Paul,

I have noted just under 13A on the 5.2V supply on my HP 8663A.
The 8662 should not be much different.

Regards,
Askild


On Sat, May 29, 2021 at 8:10 PM paulswed <paulswedb@...> wrote:
Hello to the group.
Working on a HP 8662a power supply issue. Its a complex switching power supply.
Most of the power supplies use the classic sense resistor and a base emitter sense voltage of .6V so current can easily be calculated.
But the 5.2V power supply is a huge question. It uses a .005 ohm resistor. The service manual doesn't say what it can deliver. But looking at the diodes they can handle 35 amps. The wire to the diodes is 14 Gauge appear to handle less current. Though the wires are about 1" long. Traces indicate maybe 14 amps.
Measuring a 8662b that works but can't be opened. The power draw in VA is 300 VA. Subtracting the other supplies leaves 217 VA or 40 amps at 5.2V. I really do not believe that number. But can not find what else could be consuming lots of power.
Also actually providing a voltage into the overcurrent circuit shows that 3 mv is the trip point .003V/.005 ohms is .6A. So thats not correct.
The reason I need to figure this out is to insert external supplies temporarily to confirm nothing else is an issue with the 8662 and would like to set a reasonable current limit. I have 50 and 60A supplies. Kind of scary inserting something that large.
The switcher is very very good at eating transistors in about 1 second.
Appreciate any help.
Thank you
Paul
WB8TSL

Re: Three-volume Book about Hewlett Packard South Queensferry history to be available soon

 

FYI:

Acknowledgement

"We expect to dispatch from Scotland, UK, via AIRMAIL
on the 16 July 2021 and will email you again then
with dispatch details including your Invoice."

Larry
AC9OX
Re: HP 8662a 5.2V current draw

 

On Sat, May 29, 2021 at 11:10 AM, paulswed wrote:
Hello to the group.
Working on a HP 8662a power supply issue. Its a complex switching power supply.
Most of the power supplies use the classic sense resistor and a base emitter sense voltage of .6V so current can easily be calculated.
But the 5.2V power supply is a huge question. It uses a .005 ohm resistor. The service manual doesn't say what it can deliver. But looking at the diodes they can handle 35 amps. The wire to the diodes is 14 Gauge appear to handle less current. Though the wires are about 1" long. Traces indicate maybe 14 amps.
Measuring a 8662b that works but can't be opened. The power draw in VA is 300 VA. Subtracting the other supplies leaves 217 VA or 40 amps at 5.2V. I really do not believe that number. But can not find what else could be consuming lots of power.
Also actually providing a voltage into the overcurrent circuit shows that 3 mv is the trip point .003V/.005 ohms is .6A. So thats not correct.
The reason I need to figure this out is to insert external supplies temporarily to confirm nothing else is an issue with the 8662 and would like to set a reasonable current limit. I have 50 and 60A supplies. Kind of scary inserting something that large.
The switcher is very very good at eating transistors in about 1 second.
Appreciate any help.
Thank you
Paul
WB8TSL
----
Is the schematic of "A7A2 Control" block available online? I could only find a block diagram.
Ozan
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