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