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Date
Re: RF Voltmeter?

[email protected]
 

I have a Ballantine 323 AC voltmeter and a Boonton 91H RF "millivoltmeter".? The Ballantine is solid-state and has a usable range to 20 MHz, the Boonton is vacuum-tube and has a usable range to 1200 MHz.? The Boonton meters are relatively easy to find, but the probes, cables and probe accessories are often very scarce.? Both meters have the lowest scale of 1 mV FS.??? The meters have different intended purposes.? I'm sure that you could use them interchangeably for a few limited applications, but that's not what they were designed for.

Mike, WB0LDJ
mharmon at att dot net
436A power meter front panel inquiry

 


Before I resort to that famous auction site I wanted to inquire on this list to see if anyone might have parted out a 436A power meter and have a spare front panel in good condition available.? I just acquired a 436A that is in near new condition but, as many of us may experience in our gatherings someone decided to remove labels from the front panel and utilized a pocket knife, paint scraper, razor blade or something of that nature.? My unit unfortunately has lost much of the panel nomenclature along the right 1/3 or slightly greater area from what appears to be scraping and some form of aggressive solvent (MEK, acetone, lacquer thinner, etc.) applied to the plastic surface.

?

The upside was a very reasonable price which included a working 18 GHz power sensor and the 30W attenuator as well.? The power meter itself is cosmetically perfect all the way around and works well.? Fortunately no one decided to use a permanent marker on the cover (classical military disposal depot trick). It’s just sad knowing that the non-technical don’t understand how to treat a fine piece of expensive (and working) equipment.


Thanks,


Greg
Re: Just purchased HP 3586B--EBAY

 

Hi Lamont

According to the HP 3586 user manual the B variant already has a BNC input that is switchable between 50 and 75 Ohms.

The A and B variants were teleco "specials" the C variant was the general use one, however it is quite possible that your B may not be as the manual and was customised for a specific client.

A by far larger problem with 3586's is the NiCad ram backup battery which leaks and contaminates/corrodes the PCB edge connector, this must be the first check that you do.

73 George G6HIG
________________________________________
From: hp_agilent_equipment@... <hp_agilent_equipment@...> on behalf of nojunk@... [hp_agilent_equipment] <hp_agilent_equipment@...>
Sent: 13 October 2017 17:14
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Just purchased HP 3586B--EBAY

I waiting to get it, I 'm pretty excited, but also concerned it will need repair.
In the listing I note is the display has error code of CE-1. The manual says,
"Operator error, Attempt made to Manualy change the FULL SCALE while in Auto Range"
So I hope that is not a real problem.
I will be changing the WECO input connectors to BNC. I note the unit is 75 ohm, I'll be working with
50 ohms.Is it wise to put a 50 ohm to 75 ohm L pad internal when I install the BNC connector?
And then note, "all measurements are MINUS5.72 DB".
What would I add/subtract if I just plugged a 50 source into the 75 ohm input?
Thanks, Lamont
.
Re: Just purchased HP 3586B--EBAY

 

Lamont,

Download the manual, look at the matching network. You will see how easily you can make it selectable for 50 or 75 or whatever tweaks your tuner. There may be several illustrations for different available networks, depends on ordered options. I suggest you read the manual or you will be scratching your head why things do not work the way you think they should. Look at 3586C, that has clearly the 50 / 75 selectable diagram you may want to use, or not!

Dennis


--------------------------------------------

On Fri, 10/13/17, nojunk@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Subject: [hp_agilent_equipment] Just purchased HP 3586B--EBAY
To: hp_agilent_equipment@...
Date: Friday, October 13, 2017, 1:14 PM






























I waiting to get it, I 'm pretty excited, but also
concerned it will need repair.
In the listing I note is the display has error code of?
CE-1. The manual says,
"Operator error, Attempt made to Manualy change the
FULL SCALE while in Auto Range"
So I hope that is not a real problem.
? I will be changing the WECO input connectors to BNC.
I note the unit is 75 ohm, I'll be working with
50 ohms.Is it wise to put a 50 ohm to 75 ohm L pad internal
when I install the BNC connector?
And then note, "all measurements are MINUS5.72
DB".
?What would I add/subtract if I just plugged a 50
source into the 75 ohm input?
???????????????????????
Thanks, Lamont
.
Re: RF Voltmeter?

 

The big limitation in using probe type RF voltmeters, is the probe. It becomes very difficult to establish a good low impedance ground above perhaps 700 MHz, making measurements questionable. This also applies to oscilloscope probes.

The impedance of any probe also decreases with frequency. Trying to make measurements in a relatively high impedance environment, may become impossible even at low microwave frequencies.

Working in a 50 or 75 ohm transmission line system has been the industry standard for a long time.

Stuart?
K6YAZ
Los Angeles, California
Re: Why Under FILa file for the 3586 with 419MB, but nothing there?

 

?I don't see any other fole for the 3586!
????????????????? Lamont
Re: Why Under FILa file for the 3586 with 419MB, but nothing there?

 

?
The folder is empty so?the upload failed or something. Maybe they were deleted.
The 419MB is the total space used of the 2GB allocation. Try another file.
?
Alan
G3NYK

----- Original Message -----
Sent: Friday, October 13, 2017 9:53 PM
Subject: [hp_agilent_equipment] Why Under FILa file for the 3586 with 419MB, but nothing there?

Under FILES> 3586> 419MB---- file empty.
Anyone known why I can't see the files?
????????????????????????? Thank, Lamont.
Why Under FILa file for the 3586 with 419MB, but nothing there?

 

Under FILES> 3586> 419MB---- file empty.
Anyone known why I can't see the files?
????????????????????????? Thank, Lamont.
Just purchased HP 3586B--EBAY

 

I waiting to get it, I 'm pretty excited, but also concerned it will need repair.
In the listing I note is the display has error code of? CE-1. The manual says,
"Operator error, Attempt made to Manualy change the FULL SCALE while in Auto Range"
So I hope that is not a real problem.
? I will be changing the WECO input connectors to BNC. I note the unit is 75 ohm, I'll be working with
50 ohms.Is it wise to put a 50 ohm to 75 ohm L pad internal when I install the BNC connector?
And then note, "all measurements are MINUS5.72 DB".
?What would I add/subtract if I just plugged a 50 source into the 75 ohm input?
??????????????????????? Thanks, Lamont
.
Re: Frequency calibration?

 

You need to investigate, and measure Allen Variance, a better
indication of the quality of an oscillator. What you will most
likely find is the GPS disciplined oscillator, though very good
in terms of "accuracy", is poor for short term Allen Variance,
and that the HP 107 is very good for short term Allen Variance,
and poor for long term Allen Variance.

This path is well trodden for a group of people that are known
as timenuts, and they have a group of their own where they
discuss such things.

-Chuck Harris

jtml@... [hp_agilent_equipment] wrote:

We need extreme freq stability for our master freq reference for a particle accelerator that is 770 meters long. The original 46 year old oscillator was first a HP107BR special that was at 6.289xxxx MHz, then multiplied up with a TCI multiplier assembly. Later it was HP105B, again special crystal in double oven setup. Backup was a Vectron oscillator. Four years ago, a digital engineer replaced the crystal sources with a Meridian End Run GPS-disciplined oscillator and a TCI phase locked assembly with multipliers. This is used to generate a 100.625 Mhz, 201.25 Mhz and 805 MHz reference. With phase stability giving trouble, I took to comparing the GPS ultra-stable reference to the HP105B, 10 MHz vs 6.289xxxx. I used a HP 5372A dual channel frequency analyzer, and recorded histograms and stats of each oscillator. The GPS-disciplined oscillators are clearly inferior by a factor of 10 for medium term stability over a few hours. Two of them were tested. Then I found an old Racal Rubidium oscillator in VXI format. It works great. The moral of this story is, specs on paper aren't always enough. The GPS oscillators claimed 10^-11 and such, over 24 hours. But over shorter term even, they jumped around and covered a few millihertz spread. Stanford Research has a nice crystal oscillator that is also available as a Rubidium oscillator option. These are not very expensive.
Re: Frequency calibration?

 

I liked the story about the man with 3 watches. This is what measurement is all about, making a conclusion of the data that you have. The measurements give you an indication of the precision you have but not much about accuracy. Your data can be off by x ppm, and you can not tell…


G?ran
Re: Frequency calibration?

 

"Not very expensive" as in "compared to buying a particle accelerator" ? ;)
Re: Some HP 8341A questions

 

开云体育

Hi,

I was able to remove theYTO from the instrument and test it with the aid of a spectrum analyzer and a few power supplies. Mine needs +20V, -10V, and +5V.



With a coil current of approx. 50mA, I was able to see some oscillation on the spectrum analyzer. YAY!

However, as soon as I installed the YTO back in the instrument, it stopped working.
I found out why: The Main Coil, pin 9, has a connection to ground. As one can see, if pin 9 on the A44 YIG OSC Assembly has a connection to ground, this creates a short circuit and -40V are applied to the main coil. Then, the tuning current is so incredibly high that the YTO won't oscillate.

As soon as I remove the YTO from the instrument, it works fine because with my lab power supplies I have no ground connuection and therefore can properly apply the tuning current.

I wonder now whether it could theoretically be possible, somehow, to open the YTO, find the short circuit and place some isolation tape or so. Has anybody ever done something like that? the YTO microcircuit is definitely fine and oscillates, as it should, but the main coil is somehow connected to the housing, which, according to the schematics, should not be the case I think.


Any ideas?

Best
Tobias


From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Wednesday, October 04, 2017 23:28
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Re: Some HP 8341A questions

?

Yes, it is possible to test the YTO out of the box. It usually needs +15V, -5V. Heater is not necessary for it to oscillator.


Be very careful about the FM coil. I would just tune the main coil only. You need an SA to watch the output. It's usually at +10dBm.

Regards,
Calvin
Re: Frequency calibration?

 

We need extreme freq stability for our master freq reference for a particle accelerator that is 770 meters long.? The original 46 year old oscillator was first a HP107BR special that was at 6.289xxxx MHz, then multiplied up with a TCI multiplier assembly. Later it was HP105B, again special crystal in double oven setup. Backup was a Vectron oscillator. Four years ago, a digital engineer replaced the crystal sources with a Meridian End Run GPS-disciplined oscillator and a TCI phase locked assembly with multipliers. This is used to generate a 100.625 Mhz, 201.25 Mhz and 805 MHz reference. With phase stability giving trouble, I took to comparing the GPS ultra-stable reference to the HP105B, 10 MHz vs 6.289xxxx. I used a HP 5372A dual channel frequency analyzer, and recorded histograms and stats of each oscillator. The GPS-disciplined oscillators are clearly inferior by a factor of 10 for medium term stability over a few hours. Two of them were tested. Then I found an old Racal Rubidium oscillator in VXI format. It works great. The moral of this story is, specs on paper aren't always enough. The GPS oscillators claimed 10^-11 and such, over 24 hours. But over shorter term even, they jumped around and covered a few millihertz spread. Stanford Research has a nice crystal oscillator that is also available as a Rubidium oscillator option. These are not very expensive.
Re: Frequency calibration?

 

Thanks to all that responded. I am playing with a receiver for Navtex. Problem there is that the nearest station only transmits for 10 minutes (max) every four hours so that makes tuning the receiver part a bit awkward.

Hence I need to be able to use a RF generator instead and a counter to make sure my LO and IFs are correct. The detector has narrow filters in DSP so accuracy is important. Nevertheless 1/1000 should suffice for me.

With the simple setup I have now (simple GPS, 1kHz) I know that the counter is fairly accurate so I assume that if it is acurate on 1kHz, then it should be accurate on 518kHz as well.

Thanks Stuart for the tip of the eBay receiver. I have seen those, but did not know if they were any good. I take your comment as a vote of confidence, so I might end up buying one.
Re: RF Voltmeter?

 

On Thu, Oct 12, 2017 at 9:24 AM, xhfeng2002@... wrote:
Is Boonton 93 more like HP3400, HP3403?
It's similar to the HP 3400A and the Ballantine 323. The HP 3403C is
a true thermal RMS meter, with 100MHz bandwidth.
Re: RF Voltmeter?

 

The Boonton cables start to have high resistance in the shields, allowing signal ingress ion. The Boonton 91 is a tube model (The only schematic I have is for the 91CA). It has a 50K balance pot across the probe input, that is labeled as R49. It has a 22Meg resistor from each end, to one of the inputs.

Boonton makes a 100:1 divider to extend the range of their RF voltmeters.It is part number '91-7C 100:1 Voltage Divider Adapter'. Here is an example of one:

-----Original Message-----
From: "xhfeng2002@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
Sent: Oct 12, 2017 1:35 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] RF Voltmeter?

Michael,

I think you are right. From the spec, the Boonton 92 seems has better sensitivity than HP410C, I don't have neither Boonton 92 nor HP410C so I can't comment on which one is actually better. Instead I have a Boonton 91 and a HP410B, they use different diode probes, Boonton has solid state, HP has tube, both 91 and 410B are quite stable and has good consistence, their frequency range is about the same, up to 1GHz, my Boonton 91 is off a lot at the 1mV range, it could be caused by some leaking caps. The HP410B's lowest range is 1V, not quite as sensitive as the Boonton.


Henry


---In hp_agilent_equipment@..., <mike.terrell@...> wrote :

The Boonton 93 is a True RMS Voltmeter, usable to 20 MHz. Maybe he meant the model 92?

-----Original Message-----
From: "xhfeng2002@... mailto:xhfeng2002@... [hp_agilent_equipment]" <hp_agilent_equipment@... mailto:hp_agilent_equipment@...>
Sent: Oct 12, 2017 11:24 AM
To: hp_agilent_equipment@... mailto:hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] RF Voltmeter?

Is Boonton 93 more like HP3400, HP3403?

Michael A. Terrell


Michael A. Terrell
Re: RF Voltmeter?

Bob Albert
 

I have wanted an rf millivoltmeter for some time.? I was using my HP410B which is fine except it won't measure down to the millivolts.

Then I realized that my HP54542A oscilloscope has great bandwidth and sensitivity down to 5 mV per division.? The probe situation presents a problem but if I'm willing to settle for 50 mV per division I can use a 10:1 probe.? Still pretty good, and useful in many situations.? A 10 mV rms signal (10,000 uV) will show as 28 mV p-p, about 1/2 division.? That won't show at all on the 410B.

Bob


On Thursday, October 12, 2017 10:45 AM, "David Wise david_wise@... [hp_agilent_equipment]" wrote:




Apples and Oranges.? The Boonton 92 is a specialized RF Millivoltmeter.? The HP 410 is a general-purpose VTVM whose AC probe works at UHF.
“Not quite as sensitive” – yeah, by three orders of magnitude!
?
Dave
?

From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 12, 2017 10:36 AM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] RF Voltmeter?
?


Michael,?
?
I think you are right. From the spec, the Boonton 92 seems has better sensitivity than HP410C, I don't have neither Boonton 92 nor HP410C so I can't comment on which one is actually better. Instead I have a Boonton 91 and a HP410B, they use different diode probes, Boonton has solid state, HP has tube, both 91 and 410B are quite stable and has good consistence, their frequency range is about the same, up to 1GHz, my Boonton 91 is off a lot at the 1mV range, it could be caused by some leaking caps. The HP410B's lowest range is 1V, not quite as sensitive as the Boonton.
?
Henry


---In hp_agilent_equipment@..., <mike.terrell@...> wrote :
The Boonton 93 is a True RMS Voltmeter, usable to 20 MHz. Maybe he meant the model 92?

-----Original Message-----
>From: "xhfeng2002@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
>Sent: Oct 12, 2017 11:24 AM
>To: hp_agilent_equipment@...
>Subject: Re: [hp_agilent_equipment] RF Voltmeter?
>
>Is Boonton 93 more like HP3400, HP3403?



Michael A. Terrell



Posted by: xhfeng2002@...





Virus-free.

Re: RF Voltmeter?

 

开云体育

Sorry, I was thinking about the B, not the C.

?

Dave

?

From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 12, 2017 10:57 AM
To: hp_agilent_equipment@...
Subject: RE: [hp_agilent_equipment] RF Voltmeter?

?



Dave,

?

Not quite, the 410C has 15mV scale, same probe diode as 410B.

?

Henry



---In hp_agilent_equipment@..., <david_wise@...> wrote :

Apples and Oranges.? The Boonton 92 is a specialized RF Millivoltmeter.? The HP 410 is a general-purpose VTVM whose AC probe works at UHF.

“Not quite as sensitive” – yeah, by three orders of magnitude!

?

Dave

?

From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 12, 2017 10:36 AM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] RF Voltmeter?

?



Michael,?

?

I think you are right. From the spec, the Boonton 92 seems has better sensitivity than HP410C, I don't have neither Boonton 92 nor HP410C so I can't comment on which one is actually better. Instead I have a Boonton 91 and a HP410B, they use different diode probes, Boonton has solid state, HP has tube, both 91 and 410B are quite stable and has good consistence, their frequency range is about the same, up to 1GHz, my Boonton 91 is off a lot at the 1mV range, it could be caused by some leaking caps. The HP410B's lowest range is 1V, not quite as sensitive as the Boonton.

?

Henry



---In hp_agilent_equipment@..., <mike.terrell@...> wrote :

The Boonton 93 is a True RMS Voltmeter, usable to 20 MHz. Maybe he meant the model 92?

-----Original Message-----

>From: "xhfeng2002@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
>Sent: Oct 12, 2017 11:24 AM
>To: hp_agilent_equipment@...
>Subject: Re: [hp_agilent_equipment] RF Voltmeter?
>
>Is Boonton 93 more like HP3400, HP3403?


Michael A. Terrell



Posted by: xhfeng2002@...
Re: RF Voltmeter?

 

Dave,

Not quite, the 410C has 15mV scale, same probe diode as 410B.

Henry


---In hp_agilent_equipment@..., <david_wise@...> wrote :

Apples and Oranges.? The Boonton 92 is a specialized RF Millivoltmeter.? The HP 410 is a general-purpose VTVM whose AC probe works at UHF.

“Not quite as sensitive” – yeah, by three orders of magnitude!

?

Dave

?

From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Thursday, October 12, 2017 10:36 AM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] RF Voltmeter?

?



Michael,?

?

I think you are right. From the spec, the Boonton 92 seems has better sensitivity than HP410C, I don't have neither Boonton 92 nor HP410C so I can't comment on which one is actually better. Instead I have a Boonton 91 and a HP410B, they use different diode probes, Boonton has solid state, HP has tube, both 91 and 410B are quite stable and has good consistence, their frequency range is about the same, up to 1GHz, my Boonton 91 is off a lot at the 1mV range, it could be caused by some leaking caps. The HP410B's lowest range is 1V, not quite as sensitive as the Boonton.

?

Henry



---In hp_agilent_equipment@..., <mike.terrell@...> wrote :

The Boonton 93 is a True RMS Voltmeter, usable to 20 MHz. Maybe he meant the model 92?

-----Original Message-----

>From: "xhfeng2002@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
>Sent: Oct 12, 2017 11:24 AM
>To: hp_agilent_equipment@...
>Subject: Re: [hp_agilent_equipment] RF Voltmeter?
>
>Is Boonton 93 more like HP3400, HP3403?



Michael A. Terrell




Posted by: xhfeng2002@...
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