easy way to calibrate audio frequency generator?
 

I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

easy way to calibrate audio frequency generator?
 

On Sunday, February 28, 2021 at 4:27:15 PM UTC-5, Tinkerer wrote:
I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

Frequency counter. They have cheap Chinese kits on ebay that should give you readings close enough to what that generator would be used for.

easy way to calibrate audio frequency generator?
 

Tinkerer wrote:
==============
I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

** Time to get a Digital Multimeter with a frequency range.
Not crazy expensive and damn useful.

Plus very accurate.



....... Phil

easy way to calibrate audio frequency generator?
 

On 28/02/2021 3:27 pm, Tinkerer wrote:
I have a Heathkit ET-3100 electronic design experimenter that has a very basic
sine/ square wave function generator.Â* Controls all analog and no scale really.
Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 Khz on "high".Â* Exact
frequency depends on where the pot is adjusted. How can I calibrate this to be
more precise, preferably in a simple way?

Borrow a freq counter?

easy way to calibrate audio frequency generator?
 

On 28/02/2021 21:27, Tinkerer wrote:
I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator.Â* Controls all analog and no
scale really.Â* Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high".Â* Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?


One of those cheap digital guitar tuners things might point you in the
right direction ? (everybody knows somebody who plays the guitar)

I believe there are smartphone apps which display the frequency of the
signal coming in to the microphone - whilst recording it. Theres one (of
many) examples at https://audio-frequency-counter.soft112.com

Or if you know anybody with Cubase (or similar) recording software you
could get them to fire up the built in digital tuner tool and see it in
glorious technicolor

AT

easy way to calibrate audio frequency generator?
 

Cheap USB microphone, laptop, Audacity? (Audacity is free recording software with lots of extras, does frequency, etc)

easy way to calibrate audio frequency generator?
 

Tinkerer wrote:

I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

Beat it with mains hum. This should work on the low range and at least
part of the way up the high range.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

easy way to calibrate audio frequency generator?
 

Liz Tuddenham wrote:

=-===================
Tinkerer wrote:

How can I calibrate this to be more precise, preferably in a simple way?

Beat it with mains hum. This should work on the low range and at least
part of the way up the high range.

** You need to explain that idea.

The OP seems to have no test gear or clue.

....... Phil

easy way to calibrate audio frequency generator?
 

On 3/1/21 12:04 PM, Tim R wrote:
Cheap USB microphone, laptop, Audacity? (Audacity is free recording software with lots of extras, does frequency, etc)


Great idea. I have Audacity. I could just play the audio output and
either capture with mic or feed into soundcard and then see what it is
in Audacity. I think that's what I'll do, although I like Phil's
suggestion of a DVM with freq counter, been keeping an eye out for one.

easy way to calibrate audio frequency generator?
 

On 3/1/21 2:46 PM, Liz Tuddenham wrote:
Tinkerer wrote:

I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

Beat it with mains hum. This should work on the low range and at least
part of the way up the high range.


Not sure what that means, unless you mean a harmonic of 50/60 Hz. It
might be possible to beat by ear if the PC generates the tone and I
adjust the generator until it matches by ear, but I think I'm just going
to use Audacity and/or a DWM with freq ctr as suggested by Phil.

easy way to calibrate audio frequency generator?
 

On 3/1/2021 1:09 PM, Tinkerer wrote:
On 3/1/21 2:46 PM, Liz Tuddenham wrote:
Tinkerer wrote:

I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator.Â* Controls all analog and no
scale really.Â* Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high".Â* Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

Beat it with mains hum.Â* This should work on the low range and at least
part of the way up the high range.


Not sure what that means, unless you mean a harmonic of 50/60 Hz.Â* It
might be possible to beat by ear if the PC generates the tone and I
adjust the generator until it matches by ear, but I think I'm just going
to use Audacity and/or a DWM with freq ctr as suggested by Phil.

Google Online Music Tuner In the US the note A is generally considered
440HZ This one gives the frequency in Hz https://bit.ly/383gzou

easy way to calibrate audio frequency generator?
 

On 02/03/2021 05:09, Bennett wrote:
On 3/1/2021 1:09 PM, Tinkerer wrote:
On 3/1/21 2:46 PM, Liz Tuddenham wrote:
Tinkerer wrote:

I have a Heathkit ET-3100 electronic design experimenter that has a
very
basic sine/ square wave function generator.Â* Controls all analog and no
scale really.Â* Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high".Â* Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple
way?

Beat it with mains hum.Â* This should work on the low range and at least
part of the way up the high range.


Not sure what that means, unless you mean a harmonic of 50/60 Hz.Â* It
might be possible to beat by ear if the PC generates the tone and I
adjust the generator until it matches by ear, but I think I'm just
going to use Audacity and/or a DWM with freq ctr as suggested by Phil.

GoogleÂ* Online Music TunerÂ* In the US the note A is generally considered
440HZÂ* This one gives the frequency in HzÂ* https://bit.ly/383gzou



Speaking of which ... I believe some musicians are able to tune their
instruments by using the dial tone from a landline as a reference.

AT

easy way to calibrate audio frequency generator?
 

Abandoned_Trolley wrote:
======================


Speaking of which ... I believe some musicians are able to tune their
instruments by using the dial tone from a landline as a reference.


** But only after taking a huge dose of Meth first.


....... Phil

easy way to calibrate audio frequency generator?
 

On 01/03/2021 18:04, Tim R wrote:
Cheap USB microphone, laptop, Audacity? (Audacity is free recording software with lots of extras, does frequency, etc)

If you have a PC with a decent sound card you don't need an audio
frequency generator :-)

easy way to calibrate audio frequency generator?
 

On Tuesday, March 2, 2021 at 5:01:10 AM UTC-5, Abandoned_Trolley wrote:

Speaking of which ... I believe some musicians are able to tune their
instruments by using the dial tone from a landline as a reference.

AT

Wiki says the dial tone is a combination of 350 and 440 Hz. That would be an F major chord, minus the fifth. I guess you could do that. Youtube had a 12 hour long recording of a dial tone. I just tried to tune a guitar A string to that, came out 3 cents sharp by my tuner. But my tuner hears the dial tone as an F. The youtube version sounds like a square wave to my ears though.

The 60 cycle power hum doesn't work, it is halfway between a Bb (58) and a B natural (62).

easy way to calibrate audio frequency generator?
 

In article ,
Abandoned_Trolley wrote:

Speaking of which ... I believe some musicians are able to tune their
instruments by using the dial tone from a landline as a reference.

That's a great idea, but it probably mean FA to most people.

Musicians, on the other hand ... :)

--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk

easy way to calibrate audio frequency generator?
 

On Tuesday, March 2, 2021 at 4:22:06 PM UTC-5, Mike wrote:
In article ,
Abandoned_Trolley wrote:

Speaking of which ... I believe some musicians are able to tune their
instruments by using the dial tone from a landline as a reference.
That's a great idea, but it probably mean FA to most people.

Doesn't mean much to musicians either.

Most of us don't have land lines.

Most of us do have cell phones and you can get free tuning apps on them.

Or you can get a decent electronic tuner for $20.

Those two things have made a huge difference in stabilizing a pitch center. Years back you never knew what pitch a band was going to have - might be 440, 415, 175, who knows? You had to be prepared to accommodate, and some instruments could only be tuned so far. Now amateurs don't play any better in tune, but they play out of tune around an agreed upon pitch, and that makes it a lot easier.

What you hear on recordings is always autotuned. I don't understand how that works, but it may be gradually training people to expect things to be in tune. Except Sailor Sabor, of course, who holds the record for the most out of tune National Anthem ever, at the CPAC 2021 last week.

easy way to calibrate audio frequency generator?
 

Tinkerer wrote:

I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

** This link might be useful:

https://www.szynalski.com/tone-generator/

It's a variable frequency sine/square generator covering 1Hz to 20kHz with digital read out.

You can use zero beating if mixed with the output of your Heathkit unit.

...... Phil

easy way to calibrate audio frequency generator?
 

On 2/28/2021 1:27 PM, Tinkerer wrote:
I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator.Â* Controls all analog and no
scale really.Â* Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high".Â* Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?
Are you certain the problem is calibration and not really "resetability"?

Paul

easy way to calibrate audio frequency generator?
 

Paul Drahn wrote:
================

Are you certain the problem is calibration and not really "resetability"?


** Having no scale on the dial guarantees both.



....... Phil

easy way to calibrate audio frequency generator?
 

On 3/3/21 10:29 am, Tim R wrote:
... it may be gradually training people to expect things to be in tune.
Except Sailor Sabor, of course, who holds the record for the most out of
tune National Anthem ever, at the CPAC 2021 last week.


Your entire National Anthem is out of tune with the 21st century, and
the 20th too if it comes to that. Try reading the lyrics sometime and
think about how it sounds to anyone not born American.

easy way to calibrate audio frequency generator?
 

Clifford Heath wrote:

======================


Your entire National Anthem is out of tune with the 21st century, and
the 20th too if it comes to that. Try reading the lyrics sometime and
think about how it sounds to anyone not born American.


** Yeah - the " Star Bangled Spanner" is looking a bit worn out.

Probably get cancelled soon as "racist".

Maybe they could adopt: "'Born in the USA" ?

Oh ****, that's racist too !!


...... Phil

easy way to calibrate audio frequency generator?
 

Given that it started as a drinking song (in 1775) - it was, is and remains quite apt.

https://www.youtube.com/watch?v=8KcHg5ZOIgU

Peter Wieck
Melrose Park, PA

easy way to calibrate audio frequency generator?
 

On Sunday, February 28, 2021 at 4:27:15 PM UTC-5, Tinkerer wrote:
I have a Heathkit ET-3100 electronic design experimenter that has a very
basic sine/ square wave function generator. Controls all analog and no
scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20
Khz on "high". Exact frequency depends on where the pot is adjusted.
How can I calibrate this to be more precise, preferably in a simple way?

If the pot is a common type change it to a ten turn type it will give you more control and add freq counter as others said.
Jeff