Hi I am using a HP8592B to do RF measurements and the marker, after a passed
auto calibration, could be out 100 or 150 khz when measuring signals over
the 300Mhz range.

This spectrum analiser is a non synthetised VCO type, and I don't quite know
what frecuency measurement precision can be expected from it.

- Any experience on the marker frecuency precision on that type of spectrum
analiser?

A link to the manual will be apperciated.

Tks in advance

Salva

"Salvador Ferrairo" wrote in message
...
Hi I am using a HP8592B to do RF measurements and the marker, after a
passed auto calibration, could be out 100 or 150 khz when measuring
signals over the 300Mhz range.

This spectrum analiser is a non synthetised VCO type, and I don't quite
know what frecuency measurement precision can be expected from it.

- Any experience on the marker frecuency precision on that type of
spectrum analiser?

Looking in a 1991 HP catalog, I see that you can expect a readout accuracy
of no better than 0.01% of center freqency + 2% of freqency span + 5 x N MHz
(this appears to be a term for the timebase accuracy). Keep in mind that
many spectrum analyzers are not precision measurement instruments.

-NM

Rigth, I have seen that info, (0.01% of center freqency + 2% of freqency
span + 5 x N MHz), but I quite don't understand it ...

If say I am measuring a 300 Mhz signal, and I have a span of say 500 Khz..

- What is the precision or error that I can expect ?

Any hands on experience with that spectrum analizer, and in special
regarding frecuency marker precision, will be welcomed.

Salva

"Norm Mann" escribió en el mensaje
news:JeYmf.9018$Ea6.4054@trnddc08...

"Salvador Ferrairo" wrote in message
...
Hi I am using a HP8592B to do RF measurements and the marker, after a
passed auto calibration, could be out 100 or 150 khz when measuring
signals over the 300Mhz range.

This spectrum analiser is a non synthetised VCO type, and I don't quite
know what frecuency measurement precision can be expected from it.

- Any experience on the marker frecuency precision on that type of
spectrum analiser?

Looking in a 1991 HP catalog, I see that you can expect a readout accuracy
of no better than 0.01% of center freqency + 2% of freqency span + 5 x N
MHz (this appears to be a term for the timebase accuracy). Keep in mind
that many spectrum analyzers are not precision measurement instruments.

-NM

"Salvador Ferrairo" wrote in message
...
Rigth, I have seen that info, (0.01% of center freqency + 2% of freqency
span + 5 x N MHz), but I quite don't understand it ...

If say I am measuring a 300 Mhz signal, and I have a span of say 500 Khz..

- What is the precision or error that I can expect ?

Any hands on experience with that spectrum analizer, and in special
regarding frecuency marker precision, will be welcomed.

I haven't used that particular spectrum analyzer, but I've used similar
ones.
Let's deal with the first two terms:

0.01% of center frequency ( 300 MHz x .0001 = 30 KHz )
+ 5% of frequency span ( 500 KHz x .05 = 25 KHz )
= 55 KHz

Note: The catalog states that spans 10 MHz have 5% accuracy, not 2%.

This means that the readout may be 55 KHz off and still be within
tolerances. Added to this is the term: 5 x N MHz. What this is isn't
explained in the catalog, but there are other things which affect the
accuracy which may be included in this term. i.e.:
timebase accuracy/stability, readout precision and method of digitization.
Timebase accuracy (0.007%) and digitization (span/intervals) are probably
included in the first two terms. The last term might be concerned with the
frequency displays. Marker readout precision is a function of the number of
significant digits in the display. The display is essentially a frequency
counter and they typically are affected by the time base and have an
uncertainty of +/- one on the least significant digit. i.e.:
If the display shows 300, it may be 299 to 301. (3.33% error)
If the display shows 300.0, it may be 299.9 to 300.1. (0.333% error)
If the display shows 300.00, it may be 299.99 to 300.01. (0.0333% error)
.... and so on.

Hope this helps, I'm not sure I can do more to help.

-NM

In article Wc5nf.36638$Y7.27808@trnddc02,
says...

"Salvador Ferrairo" wrote in message
...
Rigth, I have seen that info, (0.01% of center freqency + 2% of freqency
span + 5 x N MHz), but I quite don't understand it ...

If say I am measuring a 300 Mhz signal, and I have a span of say 500 Khz..

- What is the precision or error that I can expect ?

Any hands on experience with that spectrum analizer, and in special
regarding frecuency marker precision, will be welcomed.


N is the 1st LO harmonic used for the front-end conversion. It is
always 1 for any frequency in the first band of coverage, so the
tolerance at 300 MHz would be +/- 5.055 MHz.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

Rigth, so if in doing the measurement of frecuency at 300 Mhz with a span of
500Khz I get say 299.870 my unit is OK, rigth ?

I don't see those big errors of 5 Mhz.

Any pointers to the user manualfor that unit ?

Salva





"John Miles" escribió en el mensaje
...
In article Wc5nf.36638$Y7.27808@trnddc02,
says...

"Salvador Ferrairo" wrote in message
...
Rigth, I have seen that info, (0.01% of center freqency + 2% of
freqency
span + 5 x N MHz), but I quite don't understand it ...

If say I am measuring a 300 Mhz signal, and I have a span of say 500
Khz..

- What is the precision or error that I can expect ?

Any hands on experience with that spectrum analizer, and in special
regarding frecuency marker precision, will be welcomed.


N is the 1st LO harmonic used for the front-end conversion. It is
always 1 for any frequency in the first band of coverage, so the
tolerance at 300 MHz would be +/- 5.055 MHz.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

In article , says...
Rigth, so if in doing the measurement of frecuency at 300 Mhz with a span of
500Khz I get say 299.870 my unit is OK, rigth ?

Sure.

I don't see those big errors of 5 Mhz.

If the analyzer doesn't have a stabilization feature, and its frequency
accuracy is that good, it is pure luck. Don't count on it being that
close at any other frequency, or remaining that close at 300 MHz for
very long.

Any pointers to the user manualfor that unit ?

Try www.manualsplus.com for a hardcopy, or if a search at agilent.com
doesn't turn anything up, ftp://ftp.agilent.com/pub/manuals/ .

-- john, EK5FX