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Re: HP 8656B

 

This is also done in finance where M is 1000 and MM is million. Really odd!

On 8/24/2018 7:19 PM, Brad Thompson wrote:
On 8/24/2018 4:25 PM, Dave McGuire wrote:
<snip>
?? I never did understand the point of the 0F13 notation and have never
particular cared for it.? Arbitrarily moving the units into the decimal
position seems like a very random thing to do.

?? But a leading zero makes 0.013F pretty readable, IMO.

?? The real problems come in, as Chuck pointed out, when the industry
does things like "MFD".? Gads am I glad those days are over!
Hello--

Another pitfall from the "good old days" awaits the beginning
restorer or repairer who examines the schematics of certain
older (tubed) radios. Some manufacturers used "M" as a
multiplier of 1,000 in resistor values.

For example, I'm looking at a schematic for a 1930s Grunow
model 1291 receiver in which various resistors sport labels of
"ohms", "M" and "megohms".

Fortunately, a little knowledge of circuit design would tell you
that using a 47M (megohm) plate resistor in an audio-amplifier
stage would be highly unlikely.

73--

Brad? AA1IP
Re: HP 8656B

 

On 8/24/2018 4:25 PM, Dave McGuire wrote:
<snip>
I never did understand the point of the 0F13 notation and have never
particular cared for it. Arbitrarily moving the units into the decimal
position seems like a very random thing to do.
But a leading zero makes 0.013F pretty readable, IMO.
The real problems come in, as Chuck pointed out, when the industry
does things like "MFD". Gads am I glad those days are over!
Hello--

Another pitfall from the "good old days" awaits the beginning
restorer or repairer who examines the schematics of certain
older (tubed) radios. Some manufacturers used "M" as a
multiplier of 1,000 in resistor values.

For example, I'm looking at a schematic for a 1930s Grunow
model 1291 receiver in which various resistors sport labels of
"ohms", "M" and "megohms".

Fortunately, a little knowledge of circuit design would tell you
that using a 47M (megohm) plate resistor in an audio-amplifier
stage would be highly unlikely.

73--

Brad AA1IP
11729C oscillations

 

I'm having some problems with some oscillations in the low noise
amplifier of my 11729C with serial prefix 2329A.
The frequency is around 27MHz, and I beleve it is from the pre-amp
section of the low noise section. Mixing products of this are also
appearing as low frequency modulations on the detected noise.

Since my testset is older than the available manuals (2509A), I was
hoping someone had one for the earlier version, either for sale or
available for scan?

As far as I can determine, all the ferrite beads are in place, as well
as the decoupling capacitor, although I question the usage of only
electrolytics as decoupling in a amplifier with response 10Hz-25MHz.
The transistors used has a Ft of 2.4GHz so I guess a next test may be
to parallel the electrolytics with some smaller ceramic capacitors.

Have anyone seen this problem before? any hint on where to go forward
is appreciated.

BR.
Thomas.
--
With Best regards, Thomas S. Knutsen.

Please avoid sending me Word or PowerPoint attachments.
Re: HP 8656B

 

On Fri, Aug 24, 2018 at 1:25 PM Dave McGuire <mcguire@...> wrote:
? I never did understand the point of the 0F13 notation and have never
particular cared for it.? Arbitrarily moving the units into the decimal
position seems like a very random thing to do.

? But a leading zero makes 0.013F pretty readable, IMO.


It was almost certainly done because decimal points would disappear, or a spec of dust would turn into a decimal point, especially on those parts lists that came from micro-fiche.? It's pretty hard to mess up 0F013.? I remember the change with resistors where 2.2K became 2K2.? It was annoying at first, but I got used to it.? It's perhaps debatable that the current practice of using the final digit as the number of zeros to add is better or worse.? So now we have 2.2K resistors marked 222... and back in capacitor land, 0.1uF marked 104.? Now which three digit number on this capacitor is its value... or is it the date code?
Re: HP 8656B

 

On 08/24/2018 09:13 AM, Kuba Ober wrote:
I somehow didn¡¯t run into the xxxF notation, where the first digit is 10^-1. Writing 13mF as 013F would be be IMHO crazy. I¡¯d understand 0F13. But of course I didn¡¯t notice the decimal point in front of the zero in Chuck McC¡¯s post ¡ª he seemingly was aware that it was not 13F, perhaps. Only one mention had the correct scaling. I think that in this day and age, all electrolytics can afford to have the capacity written in SI units with international standard scale suffixes. With a zero leading the decimal point, if applicable. It¡¯s extremely easy to misread, say .200F as 200F :) Especially after a long day. I imagine over the years some lives and/or lots of money must have been lost to mishaps of that kind. A space probe, even :)
I never did understand the point of the 0F13 notation and have never
particular cared for it. Arbitrarily moving the units into the decimal
position seems like a very random thing to do.

But a leading zero makes 0.013F pretty readable, IMO.

The real problems come in, as Chuck pointed out, when the industry
does things like "MFD". Gads am I glad those days are over!

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: 8970B Noise figure unit

 

¿ªÔÆÌåÓý

No, sorry, it was over a year ago.?


Peter

On Aug 24, 2018, at 1:01 PM, kevin kearns <kkyahoo@...> wrote:

Peter, Any recall of the physical size?
?
Kevin
----- Original Message -----
Sent: Friday, August 24, 2018 5:27 PM
Subject: Re: [HP-Agilent-Keysight-equipment] 8970B Noise figure unit

I have, but it was one I had already so don¡¯t remember the number. These kinds of fans are readily available, and the newer ones have a reduced noise level for the same CFM and backpressure.?


Peter

On Aug 24, 2018, at 11:41 AM, kevin kearns <kkyahoo@...> wrote:

Has anyone changed their fan on the 8970? Mine is very noisy and likely to fail soon. Original is a Dryco 411M-11, 30CFM, 115V.

Kevin

Re: 8970B Noise figure unit

kevin kearns
 

?
Peter, Any recall of the physical size?
?
Kevin

----- Original Message -----
Sent: Friday, August 24, 2018 5:27 PM
Subject: Re: [HP-Agilent-Keysight-equipment] 8970B Noise figure unit

I have, but it was one I had already so don¡¯t remember the number. These kinds of fans are readily available, and the newer ones have a reduced noise level for the same CFM and backpressure.?


Peter

On Aug 24, 2018, at 11:41 AM, kevin kearns <kkyahoo@...> wrote:

Has anyone changed their fan on the 8970? Mine is very noisy and likely to fail soon. Original is a Dryco 411M-11, 30CFM, 115V.

Kevin

Re: HP 8656B

 

¿ªÔÆÌåÓý

Late into this thread, may be misunderstanding the issue.

Reads like you need a 20V 24,000uF axial cap to fit in a 104 x 28mm space on a pcb?

Digi and Mouser both have a 15,000 uF axial 25V part with a 3700mA ripple that is 50x22mm - would not look 'elegant' but two of those could be fitted in parallel fairly easily in the space. If it is actually on the 5V line then Digi have a 22,000uF 16V part with 3.7A ripple that would probably work fine on it's own, that one is also small at 51x22mm.

Adrian

On 8/24/2018 5:47 PM, Chuck wrote:

Ok. thanks for the info...........BUT
?
I removed the Cap and have it in front of me as I type:
?
It says on the can:
?
Sprague
0180-3209
53D190
24000UF20VDC
-10+75%
+85C 9050H
Made in USA
?
The ONLY difference is on the Schemaitc and part list it says .013F. (ie: 13000) so there must have been a up-grade I have not found.
?
The size is:
?
4.12-in long (104.6mm)
1.128-in diam. (28.66mm)
with Axial leads
?
All the ones I have found are for screw mount and are WAY to large to fit on the A10 board.
?
Thanks,
?
Chuck McClurg
Communications, Ltd
Carson City, NV
N7UVZ
?
Re: 8970B Noise figure unit

 

¿ªÔÆÌåÓý

I have, but it was one I had already so don¡¯t remember the number. These kinds of fans are readily available, and the newer ones have a reduced noise level for the same CFM and backpressure.?


Peter

On Aug 24, 2018, at 11:41 AM, kevin kearns <kkyahoo@...> wrote:

Has anyone changed their fan on the 8970? Mine is very noisy and likely to fail soon. Original is a Dryco 411M-11, 30CFM, 115V.

Kevin

Re: HP 8656B

 

Change to P/N 0180-3209 starting w/ s/n prefix 2425A, 24000uF, 20VDC, Service Manual p/n 08656-90214- April 1986, rev 20 Oct 87.

Dave


On Fri, Aug 24, 2018 at 08:49 AM, Chuck wrote:
Ok. thanks for the info...........BUT
?
I removed the Cap and have it in front of me as I type:
?
It says on the can:
?
Sprague
0180-3209
53D190
24000UF20VDC
-10+75%
+85C 9050H
Made in USA
?
The ONLY difference is on the Schemaitc and part list it says .013F. (ie: 13000) so there must have been a up-grade I have not found.
?
The size is:
?
4.12-in long (104.6mm)
1.128-in diam. (28.66mm)
with Axial leads
?
All the ones I have found are for screw mount and are WAY to large to fit on the A10 board.
?
Thanks,
?
Chuck McClurg
Communications, Ltd
Carson City, NV
N7UVZ
Re: HP 8656B

 

¿ªÔÆÌåÓý

Hi I have found the following on the paper work I used for my last order

?

25 volt at 22000 uf?? diameter 36 mm? length 62 mm? with screw terminals

?

From: [email protected] [mailto:[email protected]] On Behalf Of Chuck
Sent: 24 August 2018 17:48
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8656B

?

Ok. thanks for the info...........BUT

?

I removed the Cap and have it in front of me as I type:

?

It says on the can:

?

Sprague

0180-3209

53D190

24000UF20VDC

-10+75%

+85C 9050H

Made in USA

?

The ONLY difference is on the Schemaitc and part list it says .013F. (ie: 13000) so there must have been a up-grade I have not found.

?

The size is:

?

4.12-in long (104.6mm)

1.128-in diam. (28.66mm)

with Axial leads

?

All the ones I have found are for screw mount and are WAY to large to fit on the A10 board.

?

Thanks,

?

Chuck McClurg

Communications, Ltd

Carson City, NV

N7UVZ

?

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Version: 2016.0.8048 / Virus Database: 4793/15883 - Release Date: 08/14/18
Re: HP 8656B

 

¿ªÔÆÌåÓý

or Grads !

Gedas, W8BYA

Gallery at 
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/24/2018 11:46 AM, Chris Hayes wrote:

Or radians

Re: 8970B Noise figure unit

 

¿ªÔÆÌåÓý

Hi just a thought

?

some fans use roller bearings if so try your local model shop for replacement bearings

?

From: [email protected] [mailto:[email protected]] On Behalf Of kevin kearns
Sent: 24 August 2018 16:41
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] 8970B Noise figure unit

?

Has anyone changed their fan on the 8970? Mine is very noisy and likely to fail soon. Original is a Dryco 411M-11, 30CFM, 115V.

Kevin

No virus found in this message.
Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15883 - Release Date: 08/14/18
Re: HP 8656B

 

¿ªÔÆÌåÓý

Ok. thanks for the info...........BUT
?
I removed the Cap and have it in front of me as I type:
?
It says on the can:
?
Sprague
0180-3209
53D190
24000UF20VDC
-10+75%
+85C 9050H
Made in USA
?
The ONLY difference is on the Schemaitc and part list it says .013F. (ie: 13000) so there must have been a up-grade I have not found.
?
The size is:
?
4.12-in long (104.6mm)
1.128-in diam. (28.66mm)
with Axial leads
?
All the ones I have found are for screw mount and are WAY to large to fit on the A10 board.
?
Thanks,
?
Chuck McClurg
Communications, Ltd
Carson City, NV
N7UVZ
?
Re: HP 8656B

 

Or radians
8970B Noise figure unit

kevin kearns
 

Has anyone changed their fan on the 8970? Mine is very noisy and likely to fail soon. Original is a Dryco 411M-11, 30CFM, 115V.

Kevin
Re: HP 8656B

 

Just be glad they didn¡¯t use zero crossings.


Peter

On Aug 24, 2018, at 10:47 AM, Chuck Harris <cfharris@...> wrote:

Personally, I was off put when they chose
Hertz as the new cycle. I always thought
wiggle was a better unit, as in megawiggles,
and gigawiggles.

-Chuck Harris

W2HX wrote:
how about KMC? kilomegacycles for GHz!
________________________________________
From: [email protected] <[email protected]> on behalf of Chuck Harris <cfharris@...>
Sent: Friday, August 24, 2018 8:03 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8656B

Ok, I'm trying hard to figure out what you think is so
odd, or special about a 0.013F capacitor.

1,000,000uF = 1.0F
100,000uF = 0.1F
10,000uF = 0.01F
1,000uF = 0.001F

0.013F is 13,000uF, which is rather common in circuits of
this sort.
Re: HP 8656B

 

Personally, I was off put when they chose
Hertz as the new cycle. I always thought
wiggle was a better unit, as in megawiggles,
and gigawiggles.

-Chuck Harris

W2HX wrote:

how about KMC? kilomegacycles for GHz!
________________________________________
From: [email protected] <[email protected]> on behalf of Chuck Harris <cfharris@...>
Sent: Friday, August 24, 2018 8:03 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8656B

Ok, I'm trying hard to figure out what you think is so
odd, or special about a 0.013F capacitor.

1,000,000uF = 1.0F
100,000uF = 0.1F
10,000uF = 0.01F
1,000uF = 0.001F

0.013F is 13,000uF, which is rather common in circuits of
this sort.
Re: HP 8656B capacitor units

 

Hayt and Kemmerly, indeed.? I think the best written textbook used in my formal education, along with Ralph J. Smith's "Circuits, Devices, and Systems".? Both are still in my library, and come off the shelf when I feel the need to refresh the "core".

Dave
Re: HP 8656B

 

¿ªÔÆÌåÓý

But you don¡¯t require 22 F? I believe you require 22000 uF?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Kuba Ober
Sent: 24 August 2018 14:01
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8656B

?

Yeah, but that is 0.022F, not 22F :)

?

Cheers, Kuba


24 aug. 2018 kl. 05:02 skrev Paul Bicknell <paul@...>:

Hi all this is easy? as I have just been through the same problem but not for HP equipment

?

Kemet do a large rang of capacitors? dependent on the size / mounting arrangement and terminals

?

For example? 40 v at 22000 uF? at 36 * 82 mm? screw terminals part number ALS30223DE040?? ?or stud mounting ALS31223DE040

Distributor ?is Mouser? please note can and stud is connected to ¨C terminal

?

Regards Paul? B

?

From: [email protected] [mailto:[email protected]] On Behalf Of Kuba Ober
Sent: 24 August 2018 06:54
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8656B

?

Although since DigiKey sells aluminum electrolytics up to 2.2F at 20V, at a cost of ~1/4k$ perhaps you do have 24F@40V. I imagine it would cost more than a thousand bucks, but I didn¡¯t search anywhere else. I can¡¯t imagine that those would let you discharge them very fast without destroying ?the metal electrode.

?

24F@40V is about 4% of a stick of dynamite if quickly discharged ¡ª but would any small (order of a soup can size) capacitor like that not have relatively high ESR??

?

Cheers, Kuba

?

?

24 aug. 2018 kl. 01:38 skrev Kuba Ober <kuba@...>:

How big is that cap, size-wise? It¡¯s unlikely to be a supercapacitor for such voltage in anything older than a few years or so, I¡¯d bet. It¡¯s a typo in the PL, and a common use of M for micro. Happens all the time. You¡¯re looking at 24,000uF @ 40V. Modern part will possibly be smaller than the one it will replaces. I have seen a 100F 48V array about 20 years ago, and it was rack-sized. That rating was with all modules connected in parallel, but they could be connected in series, too.?

?

Good luck! ¡ª Kuba Ober


24 aug. 2018 kl. 01:36 skrev Chuck <j-mcclurg@...>:

I have to thank you all for your advice on the Surge Suppressor for my bench.? I will got through all the answers and see what will work best for my Bench.

?

BUT....................

?

I was working on my 8656B tonight and found that I have about 1 VOLT of ac on the +5V line!!!? This shows that C18 could be bad.? BUT? I had to look it up in the Parts List as I was flabbergasted when I read the value.............................13,000Mf at 40V....................................

?

I looked in the PL and, Yep, it says A10C19 is .013F at 40Volts!!!!! And of course mine has to have been upgraded as it has a 24,000MF cap in it!!!!

?

Where/how am I going to come up with one of those I have no idea!

?

Hope someone can give me a clue as to what to do next, with out having to buy another 8656B for "parts" and hope it will have a good C18!

?

Thanks,

?

Chuck McClurg

Communications, Ltd.

Carson City, NV

N7UVZ

?

No virus found in this message.
Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15883 - Release Date: 08/14/18

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Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15883 - Release Date: 08/14/18
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