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Date
Re: Fake NI-USB-HS adapters on ebay.

 

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On 10/3/2015 5:11 PM, 'John Miles' john@... [hp_agilent_equipment] wrote:


The last couple of NI-USB-HS adapters I've purchased have come from Chinese vendors with multiple units for sale, but not the particular vendor or auction I mentioned the other day.??? Pricing was pretty similar, in the $150-$200 range, which is a good buy if the adapter works.??? The ones I bought worked fine with the 3048A and everything else around here, and I didn't get any notifications from the NI driver software about them not being genuine NI devices.??? So "caveat emptor" sounds like the best advice.???

I will echo exactly John's experience with one of these "used" adapters from China, it works fine with the 3048A software, and no warnings from the NI driver either.??? It has been the easiest install with my 3048A system, quite a contrast to my attempts to get both an -hp- card and an -hp- USB adapter to work on an XP computer.

I'm a happy emptor!

Dan
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

Hurray! Someone benefited from my OCD moment. :)

-----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Friday, October 23, 2015 1:04 AM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP8640B -140/+10dBm instead of -130/+20dBm?


Thanks Dave, I've annotated my paper copy.

Cheers,

On 23/10/2015, at 11:08 AM, David Wise david_wise@... [hp_agilent_equipment] wrote:

On Figure 16, page 10, the traces are mislabeled. The black traces are the 608, while the blue traces are the 8640.

JFYI,
Dave Wise

-----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 22, 2015 2:31 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP8640B -140/+10dBm instead of -130/+20dBm?


Yes there is.

, I believe.


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Posted by: Andy Gardner <ceo@...>
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Yahoo Groups Links
HP-8640B AM pulse modulation

 

Hi all,

following the recent thread about lowering the IMD of the HP-8640B
turning off the ALC or using a dc level with AM pulse modulation, I've
tried on both my 8640Bs to set AM slide to pulse and injecting a dc
level into the AM BNC, but the output level on the panel meter never
moves, as if I would turn off the output switch.
I've tried different dc levels, up to a few volts and rotating the AM
modulation knob, but nothing seem to have effect.
Are both of my generators broken in the same way or I just don't
understand how this is supposed to work?
Thanks in advance and best regards

Frank IZ8DWF
Re: HP 8341A power supply schematics

 

I will not stand on my head for this one but I have a suspicion the 40 and 41 supplies are the same.
<<<
Link to 8340B power supply drawing is much clearer than the 8341A drawing.

Dennis


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On Fri, 10/23/15, on1ev@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Subject: [hp_agilent_equipment] HP 8341A power supply schematics
To: hp_agilent_equipment@...
Date: Friday, October 23, 2015, 2:29 PM






























HI, all the HP lovers, I have received an HP 8341A
with a bad? power supply , +12 V is missing as well the
+5.2 V ,the schematics and the flowchart as an aid to
troubleshoot the power supply?available on the web are
unreadable .Is there a good soul with
decent schematic to help me ?please sent
it to ONE1V at yahoo.fr.Best
regardsON1EVGuy
HP 8341A power supply schematics

 

HI, all the HP lovers, I have received an HP 8341A with a bad? power supply , +12 V is missing as well the +5.2 V ,the schematics and the flowchart as an aid to troubleshoot the power supply?available on the web are unreadable .

Is there a good soul with decent schematic to help me ?

please sent it to ONE1V at yahoo.fr.

Best regards

ON1EV

Guy
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

The ALC pulling or modulation of the loop created IM in itself, hence it is worth doing. I know because I have measured the condition for both cases. There is little one can do because of the PIN attenuator system but that is a secondary IM contribution. On the 40's I have it is straight forward to accomplish, may be different in earlier models.



On Friday, October 23, 2015 9:20 AM, "Alan Ibbetson alan@... [hp_agilent_equipment]" wrote:


?
A friend of mine used to work as a design engineer for HP at Queensferry
in the UK, though he didn't himself work on the 8640B. I asked him about
turning off the ALC versus using external attenuators and couplers. He said

---

Turning off the ALC fixed ALC pumping. It doesn¡¯t fix the diode
nonlinearity from the detector influencing the output by being a
non-linear load, nor the non-linearity of the output amp.

Yes, a coupler with >=40dB isolation would be good. Snag is that
broadband HF ones use transformers, and to get higher frequency coverage
drives the designers to scoddy little cores. Ferrites do intermod too,
so finding a low intermod coupler is difficult.

---

The Clifton Labs website that Thomas referenced has details of couplers
that don't have significant IMD so that is the path I am going to
choose, leaving the inconvenience of ALC disabling for the day when I
can build receivers with substantially more than 100dB IMD dynamic range.

Thanks, Alan G3XAQ
Re: Spectrum analyzer choice between ESA and PSA

 

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?

Unless you need the portability, I¡¯d take the PSA over the ESA any day.

?

Much better performance including lower noise floor and phase noise, faster, more accurate amplitude measurements, and fewer adjustment pots to give trouble (they¡¯re all electronic memory values now!).

?

The only concern would be the condition, as the PSA generally is a much more expensive box so a cheap one could prove to be a problem..

?

Tom Holmes, N8ZM

?
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

A friend of mine used to work as a design engineer for HP at Queensferry in the UK, though he didn't himself work on the 8640B. I asked him about turning off the ALC versus using external attenuators and couplers. He said

---

Turning off the ALC fixed ALC pumping. It doesn¡¯t fix the diode nonlinearity from the detector influencing the output by being a non-linear load, nor the non-linearity of the output amp.

Yes, a coupler with >=40dB isolation would be good. Snag is that broadband HF ones use transformers, and to get higher frequency coverage drives the designers to scoddy little cores. Ferrites do intermod too, so finding a low intermod coupler is difficult.

---

The Clifton Labs website that Thomas referenced has details of couplers that don't have significant IMD so that is the path I am going to choose, leaving the inconvenience of ALC disabling for the day when I can build receivers with substantially more than 100dB IMD dynamic range.

Thanks, Alan G3XAQ
Re: Problem with 3MHz Filter in IF Section 8552B

 

Youre going to have to find your own photo, then post a link to it.

I may be blind, but I can't see anything from you in the Photo's section.

Regards.

Dave B.
Re: Problem with 3MHz Filter in IF Section 8552B

 

I made a folder "8552B 3MHz filter" in Photos sedction, where you can find a screenshot.
Thanks for looking.
Ernst
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

Andy Gardner
 

Thanks Dave, I've annotated my paper copy.

Cheers,

On 23/10/2015, at 11:08 AM, David Wise david_wise@... [hp_agilent_equipment] wrote:

On Figure 16, page 10, the traces are mislabeled. The black traces are the 608, while the blue traces are the 8640.

JFYI,
Dave Wise

-----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 22, 2015 2:31 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP8640B -140/+10dBm instead of -130/+20dBm?


Yes there is.

, I believe.
HP-7550 Plotter with HP-8568B

 

Hello Group. ?I have been having a blast with my new to me HP-8568B SA, and since I had an old HP-7550A plotter available, I thought it would be fun to see if I could get them connected together and get some hard copies plotted.


My plotter has both an HP-IB and RS-232 interface and thus I have connected the two instruments together with an HP HP-IB interface cable I assume is good. ?I am not having much luck in knowing where to go next as far as configuring either the plotter or SA to make them see and talk to each other. I have DL the manual for the SA but not for the plotter yet and have not read the SA yet WRT plotter operations.


Is there anyone who can work with me on or off-line to get these two working together? ?TU.


Gedas, W8BYA

Gallery at 
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

Dave Brown
 

Alan-
Not used 8640s for many years so can't answer your query, sorry. Your figures make sense to me, BTW. But check the hybrid isolation at the highest frequency you're going to test at.
If you're looking at SDR rx testing, as opposed to conventional rx architectures- you might like to check this out- implementation depends on whether you can get hold of some old white noise gear.

73
Dave, ZL3FJ

----- Original Message -----
From: "alan@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: <hp_agilent_equipment@...>
Sent: Friday, October 23, 2015 11:21 AM
Subject: Re: [hp_agilent_equipment] HP8640B -140/+10dBm instead of -130/+20dBm?


Thanks, guys. I see the ALC on/off switch S1 on board A26A4 in the manual but it involves opening the diecast box and maybe pulling the board out to toggle the switch, though it's at the top edge of the board and perhaps can be moved with a pointed stick.

The app note fig 14 suggests a hybrid with 40dB isolation will achieve the same result as disabling the ALC. My Hatfield Instruments 6dB hybrid shows 50dB isolation at 14MHz so I am inclined to go that route. Assuming everything is well behaved one might hope that keeping the generators at -10dBm (or maybe as high as 0dBm) would give spurs at least -100dBc, which is the minimum I need for evaluating 100dB DR receivers, and still give me 14dB or more attenuation to dial in with a step attenuator with receiver noise floors around -130dBm.

Does anyone know just how low the IPs go if both the ALC is disabled and a combiner are used?

Do my numbers look realistic, or have I made some idiot arithmetical error?

Thanks, Alan
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

Thanks, guys. I see the ALC on/off switch S1 on board A26A4 in the manual but it involves opening the diecast box and maybe pulling the board out to toggle the switch, though it's at the top edge of the board and perhaps can be moved with a pointed stick.

The app note fig 14 suggests a hybrid with 40dB isolation will achieve the same result as disabling the ALC. My Hatfield Instruments 6dB hybrid shows 50dB isolation at 14MHz so I am inclined to go that route. Assuming everything is well behaved one might hope that keeping the generators at -10dBm (or maybe as high as 0dBm) would give spurs at least -100dBc, which is the minimum I need for evaluating 100dB DR receivers, and still give me 14dB or more attenuation to dial in with a step attenuator with receiver noise floors around -130dBm.

Does anyone know just how low the IPs go if both the ALC is disabled and a combiner are used?

Do my numbers look realistic, or have I made some idiot arithmetical error?

Thanks, Alan
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

On Figure 16, page 10, the traces are mislabeled. The black traces are the 608, while the blue traces are the 8640.

JFYI,
Dave Wise

-----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 22, 2015 2:31 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP8640B -140/+10dBm instead of -130/+20dBm?


Yes there is.

, I believe.

On Oct 23, 2015, at 10:16 AM, alan victor amvictor88@... [hp_agilent_equipment] wrote:



There is an extensive HP application note on using the 8640 specific to IMD. Significant improvements in IMD measurement is realized but not allowing a pair of 8640 generators to modulate each other via their internal ALC loops. Hence, HP provided the ability to TURN THE GENERATOR ALC LOOP OFF. If you pop the hood on the 8640 your should find an ALC switch. Of course, I am going out on a limb and cannot recall if early units had this option, however I do believe the date code your addressing will work this option.


VISIT YOUR GROUP
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* New Photos 3

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Yahoo Groups Links
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

[email protected]
 

Yes there is.

, I believe.

On Oct 23, 2015, at 10:16 AM, alan victor amvictor88@... [hp_agilent_equipment] wrote:



There is an extensive HP application note on using the 8640 specific to IMD. Significant improvements in IMD measurement is realized but not allowing a pair of 8640 generators to modulate each other via their internal ALC loops. Hence, HP provided the ability to TURN THE GENERATOR ALC LOOP OFF. If you pop the hood on the 8640 your should find an ALC switch. Of course, I am going out on a limb and cannot recall if early units had this option, however I do believe the date code your addressing will work this option.


VISIT YOUR GROUP
? New Members 15
? New Photos 3

? Privacy ? Unsubscribe ? Terms of Use
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

There is an extensive HP application note on using the 8640 specific to IMD. Significant improvements in IMD measurement is realized but not allowing a pair of 8640 generators to modulate each other via their internal ALC loops. Hence, HP provided the ability to TURN THE GENERATOR ALC LOOP OFF. If you pop the hood on the 8640 your should find an ALC switch. Of course, I am going out on a limb and cannot recall if early units had this option, however I do believe the date code your addressing will work this option.



On Thursday, October 22, 2015 4:35 PM, "Alan Ibbetson alan@... [hp_agilent_equipment]" wrote:


?
Hello Thomas. Thanks very much for those useful references. It seems I
won't be needing external amplifiers for my simple receiver testing.
Jack at Clifton Labs mentions using LPFs to avoid confusion caused by
generator harmonics, but mine are -60dBc so I hope added filtering will
not be necessary.

Thanks everyone. Best wishes, Alan G3XAQ
--

Alan Ibbetson
alan@...
Re: HP8640B -140/+10dBm instead of -130/+20dBm?

 

Hello Thomas. Thanks very much for those useful references. It seems I won't be needing external amplifiers for my simple receiver testing. Jack at Clifton Labs mentions using LPFs to avoid confusion caused by generator harmonics, but mine are -60dBc so I hope added filtering will not be necessary.

Thanks everyone. Best wishes, Alan G3XAQ
--

Alan Ibbetson
alan@...
Re: Problem with 3MHz Filter in IF Section 8552B

 

Make sure the sweep rates used are commensurate with the IFBW - the shape will appear greatly distorted if sweeping too fast.

Ed
Re: HP-182C repair

[email protected]
 

Dave,

I have an HP182C with a 8559 spectrum analyser plugin. It too has developed a fault that I think is EHT-related.? It was working ok, then the brightness gradually increased but, the brightness control had no effect. I turned it off, waited 30 minutes and turned it on. Nothing showed on the screen.

I haven't stared the fault-finding yet, I was about to post in this forum and you got there first. You're obviously ahead of me in the game, but I wonder what your symptoms were?

73

Chris G3WIE
79661 - 79680 of 151548