开云体育

There was such a modification in June and July issues of AudioXpress (which, I am going to guess, you don't have!). Uses a pair of 1N4742 12V 1W zeners to split the supply.

There's an important utility to running the oscillator off batteries -- you're going to get a much lower noise floor and no pesky 60, 120, 180Hz power supply artifacts. You can rebuild the battery packs with Nicads, or button cells and use the existing charge circuit, or use one of the intelligent charger chips from, for instance Texas Instruments (Unitrode.)

I rebuilt the battery pack of my HP3581 wave analyzer -- and it was worth the investment.

--- In hp_agilent_equipment@..., "willcoele@..." <willcoele@...> wrote:

I have three 204B oscillators I'm restoring. One had a problem where C2 (the 3 section, 1% capacitor) had a shorted section. I replaced the shorted section with single 1%, .3uF. Close enough for the Government!

My problem is, I'm converting the battery units to AC. It has a transformer a bridge rectifier and some filtering but secondary of the transformer isn't center tapped and it's not referenced to ground. I used a 7812 and a 7915 regulator to provide the +/- 12volts but when I wired it to the transformer the plus side dropped to 5.6 volts and the minus side was 37.6 volts. The plus side was drawing more current than the minus side. To balance it out I used a 15v Zener diode on the minus side and the plus side increased to 25.75 volts.

It appeared to be working but when the frequency was set to 250to 1KHz, there was a small amount ripple on the + 12v. To reduce the ripple, I used a 1000uF electrolytic on the +12v side.

Has anyone done a similar modification? Is there a better way?

I have three 204B oscillators I'm restoring. One had a problem where C2 (the 3 section, 1% capacitor) had a shorted section. I replaced the shorted section with single 1%, .3uF. Close enough for the Government!

My problem is, I'm converting the battery units to AC. It has a transformer a bridge rectifier and some filtering but secondary of the transformer isn't center tapped and it's not referenced to ground. I used a 7812 and a 7915 regulator to provide the +/- 12volts but when I wired it to the transformer the plus side dropped to 5.6 volts and the minus side was 37.6 volts. The plus side was drawing more current than the minus side. To balance it out I used a 15v Zener diode on the minus side and the plus side increased to 25.75 volts.

It appeared to be working but when the frequency was set to 250to 1KHz, there was a small amount ripple on the + 12v. To reduce the ripple, I used a 1000uF electrolytic on the +12v side.

Has anyone done a similar modification? Is there a better way?

Hello all,

Due to our "Files" area restriction ( it is full ) I can not upload what I
promised few hours ago. Sorry !
In any case I will send to anyone who wish. Just ask.

Regards.
Roumen / LZ3RV

On Tue, Aug 30, 2011 at 12:52 PM, Roumen Velev <roumen.velev@...
<mailto:roumen.velev%40gmail.com>>wrote:

Hello all.

First - please excuse my bad English.

I am going to share my experience to restore defective HP8593A Power

Supply

(PS). Nothing useful found in the net...except: you
can send PS for repair or buy another one from Ebay.Not reasonable

for me,

so I decide to repair my self.

Looking today at mine notes I see I could write more details, but it is
late...PS already repaired, assembled and installed.
During time of repair I had no idea my experience can be shared with
you...I was very depressed/worried to return my SA to live.

Will send today pdf file in Files area with my personal hand made
schematics and pictures about this named HP8593A Power Supply repair. I
believe information there could be helpful for some of you.

Some notes:
1. Original manufacturer: MICRO Energy INC p/n 10-0060 , HP p/n

0950-1977

2. Due hand made schematics drawn from PCB's it is possible to have
errors.Schematics are partial for control part of PS and
pictures are not very good.
3. Pinout's of PS J13 DB37 connector:
+15V - 1,2,3,20,21,22
- 15V - 4,5,6,23,24,25
+ 5V - 9,10,11,12,28,29,30,31
+12V - 13,32
Fan - 7
Analog GND - 7,26,27
Digital GND - 14,15,16,17,33,34,35,36
LINE_TRIG - 18
HPWRUP - 37
LPWRON - 19
4. PS has standby power supply designed by UC3842 and P2N85

producing +18V

and *always ON.*
5. To switch PS ON connect pin 19 (J13) to GND.
6. PS need minimum 50% of nominal load current of any voltage to produce
correct +5.2V.
7. Not clear for me how +5.2V regulator works.For what is transistor

TIP30C

?
*8. When two PCB's are removed from box you have to connect four GND
points with additional wires during repair time.
See diagram.* *Two parts of metal box are used as GND wire. Due this
all PCB screw have to be installed and well
tighten when you finish repair.*
9. When assembly PS after repair be careful with:
- one of six screw for mounting of radiator is *shorter! *See drawing.
- remember how connector DB37 was. It must be uppermost when assembly
back. See drawing.

Feel free to ask for questions and good luck !

Regards and 73

Roumen / LZ3RV

Hello all.

First - please excuse my bad English.

I am going to share my experience to restore defective HP8593A Power Supply
(PS). Nothing useful found in the net...except: you
can send PS for repair or buy another one from Ebay.Not reasonable for me,
so I decide to repair my self.

Looking today at mine notes I see I could write more details, but it is
late...PS already repaired, assembled and installed.
During time of repair I had no idea my experience can be shared with
you...I was very depressed/worried to return my SA to live.

Will send today pdf file in Files area with my personal hand made
schematics and pictures about this named HP8593A Power Supply repair. I
believe information there could be helpful for some of you.

Some notes:
1. Original manufacturer: MICRO Energy INC p/n 10-0060 , HP p/n 0950-1977
2. Due hand made schematics drawn from PCB's it is possible to have
errors.Schematics are partial for control part of PS and
pictures are not very good.
3. Pinout's of PS J13 DB37 connector:
+15V - 1,2,3,20,21,22
- 15V - 4,5,6,23,24,25
+ 5V - 9,10,11,12,28,29,30,31
+12V - 13,32
Fan - 7
Analog GND - 7,26,27
Digital GND - 14,15,16,17,33,34,35,36
LINE_TRIG - 18
HPWRUP - 37
LPWRON - 19
4. PS has standby power supply designed by UC3842 and P2N85 producing +18V
and *always ON.*
5. To switch PS ON connect pin 19 (J13) to GND.
6. PS need minimum 50% of nominal load current of any voltage to produce
correct +5.2V.
7. Not clear for me how +5.2V regulator works.For what is transistor TIP30C
?
*8. When two PCB's are removed from box you have to connect four GND
points with additional wires during repair time.
See diagram.* *Two parts of metal box are used as GND wire. Due this
all PCB screw have to be installed and well
tighten when you finish repair.*
9. When assembly PS after repair be careful with:
- one of six screw for mounting of radiator is *shorter! *See drawing.
- remember how connector DB37 was. It must be uppermost when assembly
back. See drawing.

Feel free to ask for questions and good luck !

Regards and 73

Roumen / LZ3RV

I forgot to mention that it is important to glue the plastic tube to the nozzle otherwise the pressure will send the whole assembly including needle across the room. I used a plumbers PVC adhesive.
Dick

--- In hp_agilent_equipment@..., "tcxo" <tcxoe@...> wrote:

Interesting and informational!

Thanks,
Greg

----- Original Message -----
From: ferrymanr
To: hp_agilent_equipment@...
Sent: Monday, August 29, 2011 12:42 PM
Subject: [hp_agilent_equipment] Re: 8558B centre frequency wildly unstable above 1250MHz

I have a customised nozzle for my aerosol can of contact fluid. I still have the supplied 10cm length of tube but have fitted a hypodermic needle to the end. This allows me to get a little fluid into awkward places without spraying everything else. A careful inspection of the 10 turn potentiometer with a watchmakers lens showed that there is a tiny gap to the side of ech end connnection. I squirted it in there. The Bourns potentiometer fitted and many others have the rear cover held on with metal clips but I did not want to release these in case the whole thing came apart. That little dribble that got in did the trick.
Dick

Interesting and informational!

Thanks,
Greg

----- Original Message -----
From: ferrymanr
To: hp_agilent_equipment@...
Sent: Monday, August 29, 2011 12:42 PM
Subject: [hp_agilent_equipment] Re: 8558B centre frequency wildly unstable above 1250MHz

I have a customised nozzle for my aerosol can of contact fluid. I still have the supplied 10cm length of tube but have fitted a hypodermic needle to the end. This allows me to get a little fluid into awkward places without spraying everything else. A careful inspection of the 10 turn potentiometer with a watchmakers lens showed that there is a tiny gap to the side of ech end connnection. I squirted it in there. The Bourns potentiometer fitted and many others have the rear cover held on with metal clips but I did not want to release these in case the whole thing came apart. That little dribble that got in did the trick.
Dick

I guess no one is interested in these, as I've gotten no offers. If I don't sell them here for a small price, later in the week I'm going to list them on ebay. They seem to fetch a rather ridiculous price there.

As for whether they work, as I said, I have no way to test these. However, they came from a shop that was in the habit of tagging defective equipment and putting it in a back room. These probes were not tagged and were in the shop area with the working equipment. Based on this and the fact that all the other equipment in the shop worked, I'd say that these probes are most likely OK.

--- In hp_agilent_equipment@..., "mojoehand" <mojoehand@> wrote:

I have two HP 54701A 2.5 GHz Active Probes in plastic cases. They look complete and almost new, but I have no way to test these. I'll sell these cheap, so make me an offer. Shipping within the US will be $10 extra for Priority Mail.

It is still useful information! Thanks to all.

I have a Velleman two channel digital scope that runs on the USB on a
computer. It will do X-Y and I may try that for the units that have
analog outputs.

However for the 4815A I need two verticals and a horizontal because it
plots Z and Phase. Using the Velleman as a dual I/P scope with a
matching sweep speed and triggering it from the 4815A may work, but
sounds tricky.

I wonder about building a PIC circuit to record Impedance, Phase, and
Sweep and then sending this to another program (Excel?), or has
someone done this? Perhaps the old plotter is easier. I have seen
various adapters to get away from the HP pens that dry out after a
year even if unused. They are also entertaining to watch.
Peter.

--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>, werner haussmann
<w_haussmann@...> wrote:

So I looked up the 4815A and it does not have a screen. My reply

below was only meant for instruments with a screen. Sorry

So I looked up the 4815A and it does not have a screen. My reply below was only meant for instruments with a screen. Sorry

Congratulations Dick!

It might be helpful to the rest of us to know the details of how you injected the cleaner. Did you drill a hole into the case? Or???

Cheers!
Greg


----- Original Message -----
From: ferrymanr
To: hp_agilent_equipment@...
Sent: Monday, August 29, 2011 4:23 AM
Subject: [hp_agilent_equipment] Re: 8558B centre frequency wildly unstable above 1250MHz



Found that a new Bourns 10 turn pot is rather expensive so took the risk of injecting a little jungle juice into it. Now the 8558B is back to normal. I love simple faults.
Dick G4BBH

--- In hp_agilent_equipment@..., "tcxo" <tcxoe@> wrote:

Noisy / Intermittent / Bad tuning potentiometer?

-Greg

----- Original Message -----
From: ferrymanr
To: hp_agilent_equipment@...
Sent: Sunday, August 28, 2011 4:26 PM
Subject: [hp_agilent_equipment] 8558B centre frequency wildly unstable above 1250MHz



I have an 8558B which becomes totally unstable if the centre frequency is set above about 1250MHz at any span setting. If the span is sufficiently wide it is clear that the SA it is covering perfectly up to about 1550MHz or 1600MHz with some loss of sensitivitity at the top end. When the centre frequency is set above about 1250MHz the frequency display becomes random from blank up to some random number. This indicates to me that the control voltage is unstable above that frequency setting. The display looks like it is jumping all over the spectrum (have I discovered 'spread spectrum').
Any suggestions as to a likely cause or common problem before I delve into the murky depths.
Thanks
Dick G4BBH





[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

A simple question to anyone who may know: what are the legalities of copying HP service manuals? Some of them seem to be in the public domain, since they are offered on the HP information web site. But some of these electronic manuals are very low resolution, and practically unusable for repair purposes. Did each piece of test gear come with a service manual or did they have to be purchased separately? Just curious, since the market for used service manuals commands a premium for the printed materials.

Thanks,
br4