Those seem ok as the unregulated supplies.

Peter

On Nov 3, 2018, at 3:36 PM, Tony Goodhew <tony_goodhew@...> wrote:

Hey All,

My 8902A stopped powering up and I've just started looking at the power supply.

I worked through the manual troubleshooting steps and it seems to leave the finger pointing at the regulators (basically no rail other than the +15 came up when I tried the steps and it doesn't appear to indicate a short in any other area).

Looking at the unregulated -15V and +5V I'm seeing -23.5V and +10V. I understand they're not regulated but that seems a bit far away from the values on the schematic.

Is this expected or should they be closer to -15V & +5V?

Thanks,

TonyG

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Hubbell is a good source of US standard industrial and residential electrical connectors:
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8560E New to Me: Some Issues & Questions

?

While I have an extensive background in computers, communications and electronics in general, I have just recently gotten back to hands-on troubleshooting and repair after 50+ years on the business side of technology. I wanted to know more about spectrum analyzers so decided to purchase a project instrument as a learning tool. Some months ago I found a listing for an Agilent 8560E on one of the amateur radio sale/swap forums; the seller described it as “working” and in good condition, so I made an offer he could easily refuse, but he didn’t! ?I wound up with s/n 39434A04625 and it was much as represented. The physical condition is excellent, and except for one small blemish on the case, it might pass for new. When I originally received the instrument several months ago, I powered it up to see if it could get through the onboard diagnostics; it passed all of these tests and went on the shelf until I could devote more time to the project. It’s now back on the bench and I am starting to dig in. For a first quick & dirty evaluation, I compared the results on the 8560E to two other spectrum analyzers using a calibrated signal generator over the range of 100 KHz to 520 MHz (top end for my signal gen), and the results across all three SAs were virtually identical. In this process I noticed two issues that I’d like to learn more about:

1.?????? The alphanumeric information on the screen is irregular in appearance. It is readable in every case, but the brightness varies within each character. The signal trace and graticule traces do not have this problem. I looked through the service manual and it mentions something like this but the troubleshooting tips seem vague and limited in scope.

2.?????? In looking at the elapsed time readout via the Recall function, I am seeing what appears to be 60432 hours. Or is it 6043.2 hours, with the decimal point missing? Seems unlikely to me that it could be the higher number, but perhaps so. Neither the User or Service manual seem to give definitive info on the format of this number.

?

Any constructive guidance on these issues much appreciated. Given the nice overall condition of this instrument, I am somewhat inclined to invest some dollars to deal with known issues which arise with these instruments over time. Any pointers to a guru who would be willing to take this on also appreciated.

?

RB

I finally have time to work on my SA. I tried to remove the 8559A from my HP853A by loosening the Locking Knob and extracting it about an inch. I tried removing the module but it doesn't budge.

The module hasn't been removed in years; I don't know if is just tight or if something is amiss with the Locking Knob.

How does the Locking Knob work? When you tighten it clockwise does it have a locking tab which holds the module in place? When I try to tighten it is just turns clockwise and doesn't catch a latch or thread.?

I don't want to force the module out without breaking anything? Any suggestions?

Mike N2MS

?

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Sorry, this is a bit off-topic for the HP/Agilent list, but I'm hoping someone, (probably from the USA), can help me.

I bought a Gamma high-voltage regulated power supply (0-15 kV, 0-12 mA).



from eBay.

The UK seller said it is 120 V, so needs a transformer to run from the UK mains, The mains voltage here is supposed to be 230 -6%/+10%. But I have my suspicions that the UK seller may be wrong, as the US manufacturer sent me a manual on the power supply, which says its 220 VAC. But they wrote it is a 20-year old custom design. (It's entirely possible someone has changed things.)

Am I right in thinking the plug attached to this is not designed for 120 V use, but instead for 240 V? When I look at it, with the earth pin at the top, the live/neutral are horizontal. The live/neutal pins are approximate 1/4" across, with approximately 1/2" between them, so there is approximately 1" between the two furthest edges of the pins.

I know one can always start at a low voltage, and I have a variac. But I'm also aware in some cases that using too low a voltage can damage equipment. So if this thing is supposed to take 220 V, I'd rather not start with 120 V.

The manual has no tolerance for the mains voltage - it just says 220 VAC. My own voltage is typically 235 V.

Some time ago the voltage was logged here for a period of 4 days and peaked at 255 VAC (RMS value), but the transformer taps have since been changed, and the voltage dropped 5%, so I think it might peak at 243 VAC RMS - and that would only be very occasionally.

One other thing. When I cut this mains plug off, what colour cables would I expect to see, and what would be live and neutral?

Here in the UK, neutral is very close in voltage to the earth wire - ideally, it is zero. Would there be an equivalent wire colour on this mains lead?

This thing can produce 15 kV at 12 mA, which I would guess would give someone a nasty burn at the very least, and could even be fatal. But my biggest concern at the minute is how to get power to this.

Dave



--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Sorry, this is a bit off-topic for the HP/Agilent list, but I'm hoping someone, (probably from the USA), can help me.

I bought a Gamma high-voltage regulated power supply (0-15 kV, 0-12 mA).



from eBay.

The UK seller said it is 120 V, so needs a transformer to run from the UK mains, The mains voltage here is supposed to be 230 -6%/+10%. But I have my suspicions that the UK seller may be wrong, as the US manufacturer sent me a manual on the power supply, which says its 220 VAC. But they wrote it is a 20-year old custom design. (It's entirely possible someone has changed things.)

Am I right in thinking the plug attached to this is not designed for 120 V use, but instead for 240 V? When I look at it, with the earth pin at the top, the live/neutral are horizontal. The live/neutal pins are approximate 1/4" across, with approximately 1/2" between them, so there is approximately 1" between the two furthest edges of the pins.

I know one can always start at a low voltage, and I have a variac. But I'm also aware in some cases that using too low a voltage can damage equipment. So if this thing is supposed to take 220 V, I'd rather not start with 120 V.

The manual has no tolerance for the mains voltage - it just says 220 VAC. My own voltage is typically 235 V.

Some time ago the voltage was logged here for a period of 4 days and peaked at 255 VAC (RMS value), but the transformer taps have since been changed, and the voltage dropped 5%, so I think it might peak at 243 VAC RMS - and that would only be very occasionally.

One other thing. When I cut this mains plug off, what colour cables would I expect to see, and what would be live and neutral?

Here in the UK, neutral is very close in voltage to the earth wire - ideally, it is zero. Would there be an equivalent wire colour on this mains lead?

This thing can produce 15 kV at 12 mA, which I would guess would give someone a nasty burn at the very least, and could even be fatal. But my biggest concern at the minute is how to get power to this.

Dave



--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100