Signal generator calibration

1/31/2011 6:32:55 PMMitch

Hello to all,

I have a Heathkit signal generator and have the manual. There seems to be several techniques to calibrate the generator using a radio or the manual. I was reading some posts on ARF and i thought i read where someone recommended using a frequency counter to check/calibrate the signal generator if you have one. Is this a good idea?

Thanks,
Mitch

1/31/2011 6:35:04 PMLou

Mitch:

I usually connect a frequency counter to my generator before I use it. Some generators have an accessory BNC output so that you can connect the counter and use another output from the generator.

I even have a WWII unit that I use with a modern counter this way.

Lou

:Hello to all,
:
:I have a Heathkit signal generator and have the manual. There seems to be several techniques to calibrate the generator using a radio or the manual. I was reading some posts on ARF and i thought i read where someone recommended using a frequency counter to check/calibrate the signal generator if you have one. Is this a good idea?
:
:Thanks,
:Mitch
:

1/31/2011 6:55:35 PMGary W. Prutchick

Lou,

I do the same as Mitch. I have an Eico, Heath and a Precision Apparatus signal generator, all of which I have modified to add the BNC connector Mitch mentioned. This BNC is connected to my HP5326 Frequency Counter. In my opinion the frequency counter is the way to go.

Gary

:Mitch:
:
:I usually connect a frequency counter to my generator before I use it. Some generators have an accessory BNC output so that you can connect the counter and use another output from the generator.
:
:I even have a WWII unit that I use with a modern counter this way.
:
:Lou
:
::Hello to all,
::
::I have a Heathkit signal generator and have the manual. There seems to be several techniques to calibrate the generator using a radio or the manual. I was reading some posts on ARF and i thought i read where someone recommended using a frequency counter to check/calibrate the signal generator if you have one. Is this a good idea?
::
::Thanks,
::Mitch
::
:
:

2/1/2011 1:33:51 AMPeter G Balazsy

Yes.
The freq counter will absolutely be better at letting you know what freq you are at.
... and it is WAY better than just trying to read the dial on the signal generator.. that's for sure.

However.. the frequency counter ought to be calibrated as well. oscillator counters use an internal crystal oscillator as a reference... but that isn't "absolute" either as the crystal will drift with temperature.

So as long as your freq counter has been calibrated some-what recently... that's the way to go.

2/1/2011 6:46:25 AMLewis L

:Yes.
: The freq counter will absolutely be better at letting you know what freq you are at.
:... and it is WAY better than just trying to read the dial on the signal generator.. that's for sure.
:
:However.. the frequency counter ought to be calibrated as well. oscillator counters use an internal crystal oscillator as a reference... but that isn't "absolute" either as the crystal will drift with temperature.
:
:So as long as your freq counter has been calibrated some-what recently... that's the way to go.

Of coourse, a "zero beat" with WWV is the most accurate way of all, if you can do it. Broadcast stations are usuallay within a cycle or two of the correct frequency. And the above are right, counters can get out of calibration, also.
Lewis
:

2/1/2011 10:02:09 AMNorm Leal

Mitch

As others have mentioned a frequency counter is nice but you may not have one.

You can use radio stations and beat your signal generator against them. Can even use harmonics. A signal generator set to 455 will zero beat with a radio station on 910.

Norm

::Yes.
:: The freq counter will absolutely be better at letting you know what freq you are at.
::... and it is WAY better than just trying to read the dial on the signal generator.. that's for sure.
::
::However.. the frequency counter ought to be calibrated as well. oscillator counters use an internal crystal oscillator as a reference... but that isn't "absolute" either as the crystal will drift with temperature.
::
::So as long as your freq counter has been calibrated some-what recently... that's the way to go.
:
:
:Of coourse, a "zero beat" with WWV is the most accurate way of all, if you can do it. Broadcast stations are usuallay within a cycle or two of the correct frequency. And the above are right, counters can get out of calibration, also.
:Lewis
::
:
:

2/1/2011 3:30:06 PMElmer F.

Don't worry about calibration of the counter unless it is obviously wacko. Even if it is 10-4 (pretty lousy for anything with a crystal) that is only 45.5 Hz at 455KHz, likewise 10-5 (much more reasonable for a cheapie)is 4.55 Hz.

2/1/2011 7:23:13 PMPeter G Balazsy

What is "10-4 or 10-5" ?
... I've never heard that expression

2/1/2011 8:23:14 PMRichard

:What is "10-4 or 10-5" ?
:... I've never heard that expression
:
It is a mathematical expression for the error in measurement. 10 to the -4th power or 10 to the -5th power.

2/1/2011 11:14:36 PMElmer F.

Look up "scientific notation" and you'll see what this is all about.

::What is "10-4 or 10-5" ?
::... I've never heard that expression
::
:It is a mathematical expression for the error in measurement. 10 to the -4th power or 10 to the -5th power.
:

2/2/2011 7:08:23 AMLewis L

:Look up "scientific notation" and you'll see what this is all about.
:
:
:::What is "10-4 or 10-5" ?
:::... I've never heard that expression
:::
::It is a mathematical expression for the error in measurement. 10 to the -4th power or 10 to the -5th power.
::
:
:

Should read 10^-4 or 10^-5
10-4 used to be used on the CB by truckers.
Lewis

2/2/2011 8:04:08 PMPeter G Balazsy

:Should read 10^-4 or 10^-5
:10-4 used to be used on the CB by truckers.
:Lewis
:

I agree... that's why I was confused.
.. typically when raising any number to a power a carrot is used in the notation NOT a hyphen.