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Re: VNA Resonance Methodology

 

If half the length (while holding everything else constant), then you get about twice the inductance, so your resonant frequency will be about 70% what you targeted.

It is best in general to space the windings apart by something similar to the wire diameter. In the frequency range you're looking at, you'll about double the Q if you do so.

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070

On 11/25/2024 5:38 PM, Jinxie via groups.io wrote:
I think this is where I may have gone wrong. I'm winding this on a 31mm diameter paxoline former with no core as per the formulas. The wire is 0.4mm and the overall length of the solenoid should have been 20mm. Mine was less than half that as I'd wound the turns touching (yes, they are varnished). That must have thrown the calcs out. Not sure how I made such an oversight but there it is.
Re: VNA Resonance Methodology

 

I think this is where I may have gone wrong. I'm winding this on a 31mm diameter paxoline former with no core as per the formulas. The wire is 0.4mm and the overall length of the solenoid should have been 20mm. Mine was less than half that as I'd wound the turns touching (yes, they are varnished). That must have thrown the calcs out. Not sure how I made such an oversight but there it is.
?
-J.
File /All HP, Agilent and Keysight instruments in folders by part numbers/5000 to 5999/HP_5315A_Operating_and_Service_Manual.pdf uploaded #file-notice

Group Notification
 

The following items have been added to the Files area of the [email protected] group.

By: jack <jfrazer716@...>

Description:
HP 5315A operating and service manual
Re: VNA Resonance Methodology

 

To avoid disappointment with the Q that you achieve on your initial attempt, it might be worth it to list what inductance you want and what Q you would be happy with at 1.45 MHz.?
?
If I assume 50uH and about 250pF for your resonator, I think you would have to make something quite large if you were hoping for a high Q at 1.45 MHz from a classic air cored 50uH solenoid.?
This assumes you are using enamelled copper wire of maybe 1mm diameter. Having close wound turns makes the winding easier but it will obviously produce a lower Q.
?
You could always use Litz wire if this is practical for you as this should boost the Q quite a lot at 1.45 MHz even with close wound?turns.
?
The other alternative would be to use a ferrite core based inductor. It should be possible to get a Q of about 400 at 1.45 MHz with a small ferrite core inductor with about 50uH inductance. But this won't be suitable for large signal operation.
Sticky ink of schematics

 

Hello, I want to scan and save forever schematics I recently found from a warehouse. The problem is the ink. Storage conditions for decades are unknown but I assume this wasn¡¯t kept in an air conditioned environment. It wasn¡¯t exposed directly to a flood so at least I have that going for me. However, hot and cold with possible humidity in the mix for decades will still take a toll. Any tips and tricks on how to separate papers from themselves or it¡¯s plastic cover without lifting the ink?
?
-Lex
Re: HP 10811-60085 (10 MHz OCXO) No hits when searching for data...

 

I spotted my mistake as well.
?
The only 10811- I had in my junk box was a -60111 but I decided to try it
in spite of not being specified for PN anyway.
?
I also decided to replace a few capacitors around the POL regulator
on the interface board.
?
Before and after the steps above, I listended to a carrier using a 145 MHz
FM radio for hum and noise.
?
I also used a 89441 in spectrogram mode and could verify that
the power line frequency noise present close to the carrier when testing
before modifications was gone.
Also a sort of "random noise bursts" around the carrier
which could be seen at first was gone as well.
?
It would be intersting to know what types HP replaced the 8662A/8663A
with when they were discontinued.
?
Ulf
SM6GXV
Re: HP 8341B 1992 firmware version

 

Hello,
?
You can find it here:
?
Regards
Re: HP 10811-60085 (10 MHz OCXO) No hits when searching for data...

 

It has a looser spec than the standard 10811D/E:
?
Ref https://www.febo.com/pages/hp10811/HP10811-Specs.pdf
Re: HP 10811-60085 (10 MHz OCXO) No hits when searching for data...

 

The OCXO part number is 08662-60085 not 10811-60085
This is the part number for a rebuilt 10811-60111
Hope this helps
Re: VNA Resonance Methodology

 

And if you want to do a first-order correction for fringing, replace the length with [length + 0.9*radius]. This correction is important if the coil length is not very much greater than the radius. Harold Wheeler gave us this correction back in the 1920s. I find that the inductance calculated this way rarely deviates from measurements by more than a couple of percent for most practical coils, so Wheeler's is a very effective correction.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070

On 11/25/2024 3:20 AM, Renaud F5ZR via groups.io wrote:
Hi Jinxie,
Back to the fundamentals!
L=n2.mu.S/l
With mu=1.26.10-6 as your inductor is on air?
S in sq meters
l in meters
Re: HP 10811-60085 (10 MHz OCXO) No hits when searching for data...

 

The basic OCXO is used in many products. Look at the 3325 A/B manual or the 53334 A/D manuals It may vave one of several interface boards The 3325 simply alows it to e chassis mounted, while the 5334A/b has an edge connector to pug it into the chassis. I am awaiting cataract surgery, so I will not attempt yo identify whicch version you have

A6 Control Assembly 03325-66506 is used in the 3325A/B but I dont have any tepair noyes on other modeless.

Here is the maual for the base model:

On Mon, Nov 25, 2024 at 9:31?AM Ulf Kylenfall via <ulf_r_k=[email protected]> wrote:
Forum,
?
Trying to figure out what version of the 10811- oscillator
that has the suffix 60085 is, what is the spec it has
and what version that can replace it.
?
This suffix -60085 is not listed when searching for data either
on the internet or in the 10811- manual.
?
The oscillator sits in the 8663A rear and is the
reference oscillator for the signal generator.
(The instrument has the Ext VCO control input
option if that is of significance...)
?
Ulf
SM6GXV
?
?
HP 8341B 1992 firmware version

 

Dear Colleagues,
Would someone be able to send me the 1992 firmware files for the 8341B sweeper? Unfortunately, I can't find it anywhere.
Best regards,
Wojciech
HP 10811-60085 (10 MHz OCXO) No hits when searching for data...

 

Forum,
?
Trying to figure out what version of the 10811- oscillator
that has the suffix 60085 is, what is the spec it has
and what version that can replace it.
?
This suffix -60085 is not listed when searching for data either
on the internet or in the 10811- manual.
?
The oscillator sits in the 8663A rear and is the
reference oscillator for the signal generator.
(The instrument has the Ext VCO control input
option if that is of significance...)
?
Ulf
SM6GXV
?
?
Re: VNA Resonance Methodology

 

Thanks, everyone; all noted. I believe that should nail it, now.
Re: VNA Resonance Methodology

 

Hi Jinxie,
Back to the fundamentals!
L=n2.mu.S/l
With mu=1.26.10-6 as your inductor is on air?
S in sq meters
l in meters
This usually works well for me!
Hope this helps Jinxie
Renaud
?
Re: 6632B supply stuck in PROT mode, unable to reset.

 

I forgot to mention, the values for voltage match what I read on the output pins on the PCB.
?
Re: 6632B supply stuck in PROT mode, unable to reset.

 

Thanks for the info¡­ Yeah, I know, you¡¯re right, I should have thought it through before hooking things up, but I¡¯ve charged these types of batteries many times without incident, but¡­

?

Anyway, I was following the flowchart, as you recommended; Display comes on, yes, Error messages, No; Protect Annunciator On, Yes. Then it directs me to 0V, I¡¯m assuming that means Zero Volts on the VFD, it does show zero volts momentarily, then it shifts to the voltages I mentioned so I assumed ¡®No¡¯ in the flowchart and followed it to RI, and that¡¯s where I got lost. I can find no reference to RI. What is RI? I¡¯m assuming it is RI capital I no a 1.? The flowchart directs me to check RI input, A2 Interface board. Again, I can see no reference to an AI on the A2 board. What do they mean "check RI input"

?

Again, Thoughts?

~M
Re: Fan replacement in general Which type(s) to choose?

 

I'm using ready-made masks like these:



Christian


Am 25. November 2024 02:45:41 MEZ schrieb "Eric Garner via groups.io" <garnere@...>:

What are you using for the mask? Cut silicone sheet or silicone o-rings

-Eric?

On Sun, Nov 24, 2024, 11:44?AM Ch. Stromberg via <christian.stromberg=[email protected]> wrote:
Hello Ulf.

For the 115V types found in instruments like the 3314A, I'm also using Papst all metal versions with similar pressure and flow performance than the original, just to be on the safe side. I can confirm that these Papst fans have an issue with vibration. But installing them with a vibration dampening, decoupling silicone mask takes away most of the vibrations, making them a viable choice.

Christian


Am 24. November 2024 15:10:01 MEZ schrieb "Ulf Kylenfall via " <ulf_r_k=[email protected]>:
Forum,
?
Part of instrument repair and refurbishing I am most often
faced with having to replace old worn out fans.
?
Recently, repairing an old 8663A Signal generator,
the old fan had to go. Being located next to the VCO's
was perhaps a good idea.
?
I happily ordered a new Papst Ball-bearing fan which unfortunately
was the "mother of all vibrations". This fan was all metal type.
Needless to say it went out right away.
?
So - What types of bearings in general do you recommend?
and also which brands has the best reputation?
?
Ulf
SM6GXV
?
?
Re: VNA Resonance Methodology

 

¿ªÔÆÌåÓý

How did you connect the LC to the analyzer? Any cable? If yes, did you perform the VNA cal at the DUT end of the cable?

Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070


On 11/24/2024 1:24 PM, Jinxie via groups.io wrote:

Greetings, gentlemen,
?
Earlier today I was trying to establish the resonant frequency of a tank circuit I'd put together. A simple enough task, you might think - as indeed it should be! Now since I was using really old-style components: single layer air-core inductor with air-spaced variable cap I was expecting pretty good Q and a marked 'dip' with my GDO.? Fo in this case was intended to be 1.45Mhz. Anyway, I couldn't get a reliable, repeatable dip so thought I'd switch to using a VNA instead. So I put a 50 ohm resistor in series with the tank and hooked it up to the analyzer. Sanity check: the tank is a parallel arrangement so therefore a 'rejector circuit' (high impedance) at resonance. So testing for S11 (reflection) with the Smith Chart display selected, I was expecting to sweep from 1Mhz to 2Mhz and see a dot/short line on the far right of the chart for the vast majority of the sweep, whilst seeing that move to a dot to dead centre at 1.45Mhz. But that's not what I'm seeing. Have I missed something?
?
Cheers,
Jinxie
Re: Fan replacement in general Which type(s) to choose?

 

What are you using for the mask? Cut silicone sheet or silicone o-rings

-Eric?

On Sun, Nov 24, 2024, 11:44?AM Ch. Stromberg via <christian.stromberg=[email protected]> wrote:

Hello Ulf.

For the 115V types found in instruments like the 3314A, I'm also using Papst all metal versions with similar pressure and flow performance than the original, just to be on the safe side. I can confirm that these Papst fans have an issue with vibration. But installing them with a vibration dampening, decoupling silicone mask takes away most of the vibrations, making them a viable choice.

Christian


Am 24. November 2024 15:10:01 MEZ schrieb "Ulf Kylenfall via " <ulf_r_k=[email protected]>:
Forum,
?
Part of instrument repair and refurbishing I am most often
faced with having to replace old worn out fans.
?
Recently, repairing an old 8663A Signal generator,
the old fan had to go. Being located next to the VCO's
was perhaps a good idea.
?
I happily ordered a new Papst Ball-bearing fan which unfortunately
was the "mother of all vibrations". This fan was all metal type.
Needless to say it went out right away.
?
So - What types of bearings in general do you recommend?
and also which brands has the best reputation?
?
Ulf
SM6GXV
?
?
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