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Re: HP435 measuring head? kW's?

 

On Sat, Oct 10, 2020 at 7:07 AM Tom Holmes <tholmes@...> wrote:

By the way, what is involved in calibrating a power meter, not the sensor?


An 11683A, 432A plus 478A-H75 sensor, a counter and a DMM.

11683A is rare, but you can make one from a dead 8481A (and there are plenty of those around):



Then you just need a stable voltage source in the range of a few hundred uV to 15.8 V.

I made one and using a Fluke 343A as a voltage source and 34461A to measure the voltage, my 346A gave readings well within specs.

Calibrating the power reference is difficult... it requires the H75 option for the 478A sensor (good luck finding that) and a somewhat complicated procedure involving measuring voltages from the 432A.

Orin.
Re: HP435 measuring head?

 

Well if it was, I'd sure hate to be in a bad one!

On 10/10/2020 17:40, Dave McGuire wrote:
Ugh. That doesn't sound like a "good home" to me.

-Dave

On October 10, 2020 9:21:16 AM "Steve - Home" <steve-krull@...> wrote:
I wish I still had it but it went to a good home when money was tight. I¡¯ll check but I¡¯m afraid it was probably crushed for scrap.

Steve
WB0DBS



On Oct 9, 2020, at 10:06 PM, Dave McGuire <mcguire@...> wrote:

?On 10/9/20 10:52 PM, Steve - Home wrote:
Not a Cray but I had an Intel iPSC sitting in my living room for quite a while. Got a lot of attention from Intel and others.
We would SO give that a home at LSSM, if you still have it, or know where it is.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head?

 

Ugh. That doesn't sound like a "good home" to me.

-Dave

On October 10, 2020 9:21:16 AM "Steve - Home" <steve-krull@...> wrote:
I wish I still had it but it went to a good home when money was tight. I¡¯ll check but I¡¯m afraid it was probably crushed for scrap.

Steve
WB0DBS



On Oct 9, 2020, at 10:06 PM, Dave McGuire <mcguire@...> wrote:

?On 10/9/20 10:52 PM, Steve - Home wrote:
Not a Cray but I had an Intel iPSC sitting in my living room for quite a while. Got a lot of attention from Intel and others.
We would SO give that a home at LSSM, if you still have it, or know where it is.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA








--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head? kW's?

 

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Roy...

?

?

I'll assume your first sentence needed a sarcasm font. ?

?

I don¡¯t recall anyone asserting that they believed that they had a NIST traceable cal setup, but there was an implication, as you suggest, that the power meter box wasn't suspect even if not calibrated, and you are correct that the system needs to be totally 'in cal'. However, for amateur purposes (and not everyone on this list is in that category), having some other corroborating measurement at least provides some confidence that the measurements made are close enough for most amateur needs. Three corroborating measurements are even better, of course.

?

And frankly, I doubt that anyone believes that their newly acquired bargain priced sensor is reasonably accurate until the above has been done. And although most of us don¡¯t need NIST traceability for what we are doing, we'd like a little assurance that we are close enough for our needs.

?

By the way, what is involved in calibrating a power meter, not the sensor?

?

Tom Holmes, N8ZM

?
Re: Agilent 54831M

 

Don't worry, I save way more time with this group that I can ever give back, so it's really my pleasure.?

I'll upload it an other way (not zipped, so everything can be download once at a time). I'll post the link when it's ready!
Re: HP435 measuring head?

 

I wish I still had it but it went to a good home when money was tight. I¡¯ll check but I¡¯m afraid it was probably crushed for scrap.

Steve
WB0DBS

On Oct 9, 2020, at 10:06 PM, Dave McGuire <mcguire@...> wrote:

?On 10/9/20 10:52 PM, Steve - Home wrote:
Not a Cray but I had an Intel iPSC sitting in my living room for quite a while. Got a lot of attention from Intel and others.
We would SO give that a home at LSSM, if you still have it, or know where it is.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: 8673G Service Manual?

 

Hi James,
Have you managed to get hold of a copy of the service manual? So far I have not and my 9673G suffers from low output.
Generally 30 dB too low, so I suspect the final amp died. The attanuator and all other functions are OK.
There must be some doc around, they are not that rare beasts. Even a detailed circuit diagram would help.

Cheers, Hans PA0LED
YIG Oscillator #photo-notice

 

Hi?

have here an oscillator and need schematic and pinout for test.
Does somebody has a datasheet of the YIG?
Best regards
Armin
HB9MFL

IMG_6987.JPG

Re: HP435 measuring head?

 

Orin, Glad you chimed in!
I have couple 436's and when I auto zero they tend to drift a little after short period of time. I thought my sensors were at fault since my room has window AC nearby causing the room temp to fluctuate +- couple degrees.?
Re: HP435 measuring head?

 

On Fri, Oct 9, 2020 at 7:12 PM N8AUM via <n8aum=[email protected]> wrote:

To stay "on topic", I've collected 4 or 5 of the 435's just to have the cal. source that's inside. I know they are old and the freq. drifts on them but the output level is what I cares about when calibrating the sensor before I make any measurements. As old as they are I couldn't believe that they were all dead on for my needs and survived ups & fedex "gentle' handling lol


It wouldn't surprise me at all that the output level is still good.

What is a problem now with the 436A (at least on mine and with another A3 board I've tested) is that the sample and hold circuit for the auto-zero drifts excessively.? The 435A uses a very similar circuit to the 436A and I'd expect similar behavior.? In my case, the hold capacitor was excessively leaky - I dug it out of the potted circuit and tested it in a similar circuit (a source follower using a 2N7000).? I could get close to the original specs for the circuit with a very good teflon capacitor and a 2N7000, fairly close with a modern capacitor, but the original capacitor was terrible in comparison.? This is hard to test as given it's a MOSFET based source follower, the circuit is very temperature dependent.

Orin.
Re: HP435 measuring head?

 

On 10/9/20 10:52 PM, Steve - Home wrote:
Not a Cray but I had an Intel iPSC sitting in my living room for quite a while. Got a lot of attention from Intel and others.
We would SO give that a home at LSSM, if you still have it, or know where it is.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head?

 

Not a Cray but I had an Intel iPSC sitting in my living room for quite a while. Got a lot of attention from Intel and others.

Steve
WB0DBS

On Oct 9, 2020, at 8:10 PM, Dave McGuire <mcguire@...> wrote:

?On 10/9/20 8:57 PM, N8AUM via groups.io wrote:
Interesting thread!
Dave, so how long did it take the Cray to balance ur checkbook?
It was effectively instantaneous, as expected.

("ur"?)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head?

 

On 10/10/20 3:25 pm, Dave McGuire wrote:

? They really are well thought-out designs.? Even FedEx and UPS can't kill them!
Someone needs to tell FexEx and UPS that, because they still keep trying!
Re: HP435 measuring head?

 

On 10/9/20 10:12 PM, N8AUM via groups.io wrote:
("ur"?
short for "your".
Good heavens. Please don't do this, at least not here.

To stay "on topic", I've collected 4 or 5 of the 435's just to have the cal. source that's inside. I know they are old and the freq. drifts on them but the output level is what I cares about when calibrating the sensor before I make any measurements. As old as they are I couldn't believe that they were all dead on for my needs and survived ups & fedex "gentle' handling lol
They really are well thought-out designs. Even FedEx and UPS can't kill them!

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head?

 

On Fri, Oct 9, 2020 at 08:10 PM, Dave McGuire wrote:
("ur"?
short for "your".

To stay "on topic", I've collected 4 or 5 of the 435's just to have the cal. source that's inside. I know they are old and the freq. drifts on them but the output level is what I cares about when calibrating the sensor before I make any measurements. As old as they are I couldn't believe that they were all dead on for my needs and survived ups & fedex "gentle' handling lol
Re: HP435 measuring head?

 

On 10/9/20 8:57 PM, N8AUM via groups.io wrote:
Interesting thread!
Dave, so how long did it take the Cray to balance ur checkbook?
It was effectively instantaneous, as expected.

("ur"?)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: HP435 measuring head?

 

Interesting thread!
Dave, so how long did it take the Cray to balance ur checkbook?
?
Re: Hp 8563E analyzer for sale refurbished price 1725Euro

 

¿ªÔÆÌåÓý

Hello Diego the unit is sold but I get them from time to time as I do refurbish them I can keep you in mind if you like
best regards Peter

Fra: [email protected] <[email protected]> p? vegne af diego.gustin.dg@... <diego.gustin.dg@...>
Sendt: 8. oktober 2020 12:09
Til: [email protected] <[email protected]>
Emne: Re: [HP-Agilent-Keysight-equipment] Hp 8563E analyzer for sale refurbished price 1725Euro
?
Dear

I have sent you a PM on your address oz1lpr@...

BR
Diego Gustin
Re: HP435 measuring head? kW's?

 

On Thu, Oct 8, 2020 at 07:24 AM, avvidclif wrote:
Bird
... well they're still for the birds, allegedly, IMO.
Re: HP435 measuring head? kW's?

 

Hi N8ZM, et. al.:
Thanks for that.
I didn't know that Keysight (a.k.a. Agilent, a.k.a. HP) being a N.I.S.T. certified cal lab (through all the company's incarnations) was using cal equipment traceable to N.I.S.T!
Did you read the thread I posted: the one the OP above is referring to? (By the way, the OP didn't... yet spawned this orphan thread, the we are now embroiled in!)
Just because one sub-system of a system was "accurate," under N.I.S.T. laboratory conditions, at some N.I.S.T. certified lab, some time in the past... that does not mean the overall system being now used in the field is "accurate."
IMO it is gullible to maintain that a 20 year old, well worn, 150 USD 8481A, from some vendor, who tripped over it while dumpster surfing... and then added it to the Tiffany Lamp shades, he/she has for sale...on an online auction site. In my opinion, it is gullible to maintain that such a metrology device is now traceable to N.I.S.T.
Accuracy, precision, resolution, repeatability, robustness... these are all distinguishable. Guys/gals picking up that bargain HP power meter, at the hamfest... and now looking for a "head"... They might have forgot what they learned in their graduate school statistical metrology course.
And so, IMO, and allegedly... they are being taken advantage of by unscrupulousness vendors flying the caveat emptor flag.
If you buy an N8481A for about 1800 USD, or you send your bargain 6481A into Keysight for repair exor cal... then you'd still need cal on the hamfest power meter... and then you'd still have to use the right technique, under the right conditions, to get power measurements within Keysight's specs.
If someone thinks I'm wrong... I'm listening.
Best regards.
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