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Re: WTB HP-8753E Handles

 

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I would never ship it with the front handles on, I would have thought the handles would be more robust than these side straps. I have no confidence in them handling the weight.?

Rich

On Feb 25, 2022, at 12:42 PM, Lothar baier <Lothar@...> wrote:

?

Unless you find a new set the handles are fairly hard to come by ,? most companies removed them to avoid people trying to lift the units of benches using the front handles and as a result either dropping and damaging the unit and/or hurting themselves for the units that entered the used equipment market with handles the handles usually get bent up when the units were shipped and subsequently were removed by dealers ,? I fixed and calibrated hundrets of 8753D, E,ES units when I worked at tucker and 90% of the units that came in the lab either came in with no handles or the handles were bad

?

Sent from for Windows

?

From: Wilko Bulte via groups.io
Sent: Friday, February 25, 2022 11:36 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] WTB HP-8753E Handles

?

I smell a small amount OCD. But kidding aside, *beautiful* kit!

I too want my equipment as clean as possible. Which, eg for the 5342a took quite a bit of time to assemble the cosmetically best parts into my shack unit. The 2nd best looking 5342a is on loan to a ham friend, #3 is incomplete and lives in the cellar.

For those in EU, I have 2 sets of HP handles available, ex-HP 8642a, for sale/trade.

Wilko






?
Re: WTB HP-8753E Handles

 

Actually - My instrument came with no front handles, and I do not trust the straps when carrying this behemoth.

Rich

On Feb 25, 2022, at 12:36 PM, Wilko Bulte <wkb@...> wrote:

?I smell a small amount OCD. But kidding aside, *beautiful* kit!

I too want my equipment as clean as possible. Which, eg for the 5342a took quite a bit of time to assemble the cosmetically best parts into my shack unit. The 2nd best looking 5342a is on loan to a ham friend, #3 is incomplete and lives in the cellar.

For those in EU, I have 2 sets of HP handles available, ex-HP 8642a, for sale/trade.

Wilko
Re: HP 1727A CRO: Problem with the vertical output amplifier.

 

There is also no ripple on any of the voltage rails or voltage drop between U1 and U2.

Yesterday I did remove the whole board and clean U1 and U2 with isopropyl alcohol, I wanted to avoid oily things.
Re: HP 1727A CRO: Problem with the vertical output amplifier.

 

I appear to have misreported some things...

I can get pins 5&7 of U2 to be exactly the same with the balance control(R23), then on U2 pin 2 I get 42.30V and on pin 3 I get 41.81V, that is still a difference of half a volt give or take a millivolt or two, is this what causes the distortion?
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?

 

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Whoever cited parasitic inductance of resistors as something to worry about in this case is worrying way too much! The transformer will of course dominate by orders of magnitude.

-- Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 2/25/2022 10:00, Jim Adney wrote:

I just measured a very large (~3/4" x 7") 3 Ohm Ohmite Brown Devil. It measues ~3 Ohms and ~5 uH. My inductance meter is quite cheap, but I don't think it's off by a factor of 10,000.

Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?

 

I just measured a very large (~3/4" x 7") 3 Ohm Ohmite Brown Devil. It measues ~3 Ohms and ~5 uH. My inductance meter is quite cheap, but I don't think it's off by a factor of 10,000.
Re: WTB HP-8753E Handles

Lothar baier
 

¿ªÔÆÌåÓý

Unless you find a new set the handles are fairly hard to come by ,? most companies removed them to avoid people trying to lift the units of benches using the front handles and as a result either dropping and damaging the unit and/or hurting themselves for the units that entered the used equipment market with handles the handles usually get bent up when the units were shipped and subsequently were removed by dealers ,? I fixed and calibrated hundrets of 8753D, E,ES units when I worked at tucker and 90% of the units that came in the lab either came in with no handles or the handles were bad

?

Sent from for Windows

?

From: Wilko Bulte via groups.io
Sent: Friday, February 25, 2022 11:36 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] WTB HP-8753E Handles

?

I smell a small amount OCD. But kidding aside, *beautiful* kit!

I too want my equipment as clean as possible. Which, eg for the 5342a took quite a bit of time to assemble the cosmetically best parts into my shack unit. The 2nd best looking 5342a is on loan to a ham friend, #3 is incomplete and lives in the cellar.

For those in EU, I have 2 sets of HP handles available, ex-HP 8642a, for sale/trade.

Wilko






?
Re: WTB HP-8753E Handles

 

I smell a small amount OCD. But kidding aside, *beautiful* kit!

I too want my equipment as clean as possible. Which, eg for the 5342a took quite a bit of time to assemble the cosmetically best parts into my shack unit. The 2nd best looking 5342a is on loan to a ham friend, #3 is incomplete and lives in the cellar.

For those in EU, I have 2 sets of HP handles available, ex-HP 8642a, for sale/trade.

Wilko
Re: HP 1727A CRO: Problem with the vertical output amplifier.

 

On Thu, Feb 24, 2022 at 11:42 AM, Alex_03 wrote:
The input signal for the captures was not the calibrator, it was an external function generator. I chose triangle because it makes it easiest to see the distortion on the screen, sine shows it too and obviously square does not, hence the external function generator.

I completely forgot that I had my scope in AC coupling for those captures. new ones are attached along with pics of both sine and triangle on the screen, which I just realized I never attached to my original post, oops.

Attached in order of pins 3/6, 4/5, and 12/13 of U1(hopefully). I also captured the final vertical output(AC coupled so you can actually see something).
-----------
The measurement that is most puzzling is pin 7 of U2 (=pin 13 of U1) is at 27.77V, pin 5 of U2 (=pin 12 of U1) is at 27.5V but pins 2&3 of U2 are nicely balanced at 42V. If internals of U2 is exactly like the figure, 270mV difference across the input transistors should steer the current completely to pin 2 which should cause different voltages at pin 2 and pin 3 of U2.?

With zero input could you re-measure pins 12&13 of U1 and pins 2&3 of U2? Possible scenarios:
1) 165-ohm terminations at the other side of the plates drifted and not balanced anymore.
2) Look at 53.3VF supply for ripple and DC voltage while you are feeding in the signal.?
3) There may be a large voltage drop from pins 12/13 of U1 to pins 5&7 of U2, and in reality voltage at pins 5&7 of U2 could be closer at the IC terminals. If you measure DC voltages touching the IC pins vs touching components (e.g. R24/R25) do you see a difference? You may try carefully removing U1 and reseating it. Removing, cleaning terminals of U2 and reseating is also a good idea but it is trickier so you have to decide whether you are comfortable with it after reading the service manual.

I recommend focusing on why pins 5&7 of U2 are 270mV apart but pins 2&3 of U2 match to the same voltage.?

As you also wrote this is not a push-pull stage so there is no NPN/PNP cross over. Also U2 has cascoding inside but its function is beyond a simple cascode, it is built as a transimpedance amplifier.?


Ozan
Re: Off Topic : Admiralty B40 Receiver

 

On Friday 25 February 2022 11:44:46 am Harold Foster wrote:
I would also highly recommend the site:



especially the forums.
Seconded! I'm not currently active in there, but have been in the past...

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Re: Off Topic : Admiralty B40 Receiver

 

I would also highly recommend the site:



especially the forums.

Hal
Re: Off Topic : Admiralty B40 Receiver

 

¿ªÔÆÌåÓý

Hi the group you want is

?[email protected]

They talk about a lot of different WW2 radio equipment?

I assume you have the service information on the B40 note there are various versions that use different valve set ups is an A,B,C,D

The SSB adapter is in a different service manual

?

Regards Paul

?

From: [email protected] [mailto:[email protected]] On Behalf Of donald collie
Sent: 25 February 2022 15:17
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Off Topic : Admiralty B40 Receiver

?

Is there a group that would deal with the Admiralty B40 general coverage [Valve/Tube] Receiver? It`s a WW2 superhet with Loctal tubes - a real beauty. Thankyou......Don C.

Re: WTB HP-8753E Handles

 

"Why do you want the handles?? The instrument will work fine without them."

I'm not that guy!.? I love the appearance of the instruments with handles!? True, some people don't care about appearance, but these instruments were very expensive.? Sitting in front of it, the only thing that separates you from when it was 20, 30, 40 or more thousand $ is a little time.? It's no different than a used car.? "Why wash it?? It's not new"

I try to make every instrument I get look it's best.? I clean off any stickers, touch up any scratches, clean off any grunge on the paint.? I hope you do to!

Be aware that HP / Agilent used the same handle design for many years so there are at least three different color combinations.? You can see some of the minor differences in this picture of my RF bench.? For example - my 8753ES is from Agilent, but the S-parameter test set is an HP so the handle (and instrument) colors aren't the same.?

There should be plenty of the handles on that auction site.? Other people must love them too because they're usually expensive.

RF Bench Ver 2.jpg

Re: Off Topic : Admiralty B40 Receiver

 

Hello:

I own one with the SSB Adapter, and am restoring it. There is a facebook group that is active. You will see tons of technical post from me and others on restoring these fine receivers.?

73

Rich, AJ3G

On Friday, February 25, 2022, 10:17:28 AM EST, donald collie <donaldbcollie@...> wrote:


Is there a group that would deal with the Admiralty B40 general coverage [Valve/Tube] Receiver? It`s a WW2 superhet with Loctal tubes - a real beauty. Thankyou......Don C.

Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?

 

¿ªÔÆÌåÓý

I wonder what Z0 the Smith chart was normalized to? ?

?

From: [email protected] <[email protected]> On Behalf Of Jim Adney
Sent: Friday, February 25, 2022 9:08 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] How can I measure the bandwidth of an audio transformer with the HP8903B ?

?

It should also be understood that no speaker, or speakers w/crossover, will be pure resistive either. I recall seeing reviews of speaker systems where the impedance as a function of frequency was displayed on a Smith chart. I don't know whether this data came from the speaker maker or from the reviewer. This is probably more than most people want to know, but it's there.

Off Topic : Admiralty B40 Receiver

 

Is there a group that would deal with the Admiralty B40 general coverage [Valve/Tube] Receiver? It`s a WW2 superhet with Loctal tubes - a real beauty. Thankyou......Don C.
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?

 

Hi Jon,
I have no "real data", but I find it VERY hard to believe that a 10 ohm, 10 W resistor could possibly have 55 or 505 *millihenrys" of inductance.
I strongly suspect that your numbers units should be *microhenrys".
For a speaker, a small number of millihenrys is definitely reasonable, since it has a "ferrous" core.

Pete
WTB HP-8753E Handles

 

Wondering if anyone in the group has a set of what I believe are 5U handles for the 8753E. If I am not mistaking the handles were generic, and likely fit other instruments in the same form factor enclosure.? I found a set in Europe, but the shipping cost is far too great to consider.?

Rich
Re: How can I measure the bandwidth of an audio transformer with the HP8903B ?

 

It should also be understood that no speaker, or speakers w/crossover, will be pure resistive either. I recall seeing reviews of speaker systems where the impedance as a function of frequency was displayed on a Smith chart. I don't know whether this data came from the speaker maker or from the reviewer. This is probably more than most people want to know, but it's there.
Re: HP8903B - Plotting from HP-IB

 

Hello everybody,
 I got the HP82357B interface and I can finally use Pete Millett's programs.
I entered address 7 for the interface and 28 for the HP8903B.
It works well, I just wanted to understand if it is possible to delete the track or if every time you have to exit and re-enter the program.


-- Cheers
??? Attilio
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