Re: HP435 measuring head? kW's?
Building a 11683A isn¡¯t as simple as using an old 8481A and a few precision resistors. The range switch in the HP 11683A is not your run-of-the-mill SP 10 pos rotary switch. HP used a very low resistance contacts in the switch. In fact,
there¡¯s a procedure in the 11683A¡¯s manual for checking the integrity of the switch. The switch has an in house part number and Keysight lists the switch at $3.000!
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Gud luk
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Dave
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From: [email protected] < [email protected]>
On Behalf Of Orin Eman
Sent: Saturday, October 10, 2020 10:35 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP435 measuring head? kW's?
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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.
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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.
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Re: HP435 measuring head?
Well if it was, I'd sure hate to be in a bad one!
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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
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Re: HP435 measuring head?
Ugh. That doesn't sound like a "good home" to me.
-Dave
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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
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Dave McGuire, AK4HZ
New Kensington, PA
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Dave McGuire, AK4HZ
New Kensington, PA
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Re: HP435 measuring head? kW's?
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 ?
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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!
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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
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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
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Dave McGuire, AK4HZ
New Kensington, PA
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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
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Hi?
have here an oscillator and need schematic and pinout for test.
Does somebody has a datasheet of the YIG?
Best regards
Armin
HB9MFL
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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.?
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Re: HP435 measuring head?
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.
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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
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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
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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
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Dave McGuire, AK4HZ
New Kensington, PA
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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!
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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
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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
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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
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Re: HP435 measuring head?
Interesting thread!
Dave, so how long did it take the Cray to balance ur checkbook?
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Re: Hp 8563E analyzer for sale refurbished price 1725Euro
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
Dear
I have sent you a PM on your address oz1lpr@...
BR
Diego Gustin
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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.
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Dave Smith
Dave McGuire
Armin Roesch
