time-nuts@febo.com said:

Did you consider software?

Is the audio on a Raspberry Pi fast enough?

I haven't looked at any details, but you can get ARM CPUs for ballpark of $5
on eBay.  There is a good chance that one of their IO devices will let you
send raw bits via a DMA channel.

--
These are my opinions.  I hate spam.

Sure. I considered software. But I'm a hardware guy. I like designing boards. The rig was designed to do amplitude and phase simply. The final design will have a $5 48 MHz microprocessor included. I'm using that one because of speed and memory. When that proves out I might redesign for a $2 24 MHz processor. Onesies prices at Mouser

Besides the hardware better illustrates the concepts than software. And I don't have to tie up a PC if I don't want to.

I haven't priced everything out yet because the design is not done. I'd be surprised if the cost was over $20 in parts for everything - power supply not included. PCB extra.

Feel free to send this along to the list if you are inclined.

Simon
 Engineering is the art of making what you want from what you can get at a profit.
I like Polywell Fusion.

On Tuesday, January 3, 2017 5:53 AM, Hal Murray <hmurray@megapathdsl.net> wrote:

time-nuts@febo.com said:

Did you consider software?

Is the audio on a Raspberry Pi fast enough?

I haven't looked at any details, but you can get ARM CPUs for ballpark of $5
on eBay.  There is a good chance that one of their IO devices will let you
send raw bits via a DMA channel.

--
These are my opinions.  I hate spam.

You don't need to tie up a PC.    It could likely output the WWVB
signal while it was also surfing the web and reading emails.  60KHz
is NOTHING compared to displaying a you-tube video

In fact I bet your 48MHz uP could directly synthesize the signal.
Look at the ratio of 48 MHz / 60 KHz.  The uP can execute about 800
instructions during one cycle of a 60 KHz courier.    Your PC can do
a million operations during that same one cycle.

But go ahead.  I'm subscribed to another list dedicated to building
stuff with vacuum tubes.  I kind of enjoy building with that
technology.    I used to like building with 70'd vintage 74xxx TTL.
city is like lego blocks for big kids.  But as a practical matter if
you just want something to work, 21st century technology gets the job
done.

On Tue, Jan 3, 2017 at 6:49 PM, M. Simon via time-nuts
time-nuts@febo.com wrote:

--

Chris Albertson
Redondo Beach, California

Simon
Like you I tend to like hardware. But today complete micros are so cheap
and powerful they make life easy. Heck a bit to complex use 2 or 3. I like
to follow the  "Get-er-done" philosophy.

That said search the time-nuts archive for the wwvb cheatn d-psk-r. It
knows how to create the bpsk time stream aligned to wwvb then flips a BPSK
switch to remove the BPSK. This allows all of the old phase tracking
receivers work without modifications.
I used an Arduino $8 maybe and shared all of the details and software with
the group. It preserves the old AM for radios that need that modulation.
So a corrected wwvb signal can be had for cheap and it works very well here
on the east coast. As well as wwvb ever did.

Have fun and use whatever technology you like as you are the do-er, you get
to choose.

Regards
Paul
WB8TSL

On Wed, Jan 4, 2017 at 2:48 AM, Chris Albertson albertson.chris@gmail.com
wrote:

A PC can certainly generate a lot of frequencies. But if you want to use the audio channels at 60KHz there is a little problem. There is a brick wall filter in the audio channel set at about 25 KHz.

Now I could set up the audio to output 15 KHz I and Q and mix it (quadrature mixer) with 45 KHz X 4 (precision source)  to get 60 KHz. And then filter it to get the 60 KHz. Which requires some op amps. And filters. A precision 45 KHz source. A gray code counter (divide by 4).  And stuff.

Easier to work at DC (my "audio" signal) and mix that up to 60 KHz directly. Besides. I do like designing and building hardware.  Engineering is the art of making what you want from what you can get at a profit.
I like Polywell Fusion.

On Wednesday, January 4, 2017 7:48 AM, Chris Albertson <albertson.chris@gmail.com> wrote:

You don't need to tie up a PC.    It could likely output the WWVB
signal while it was also surfing the web and reading emails.  60KHz
is NOTHING compared to displaying a you-tube video

In fact I bet your 48MHz uP could directly synthesize the signal.
Look at the ratio of 48 MHz / 60 KHz.  The uP can execute about 800
instructions during one cycle of a 60 KHz courier.    Your PC can do
a million operations during that same one cycle.

But go ahead.  I'm subscribed to another list dedicated to building
stuff with vacuum tubes.  I kind of enjoy building with that
technology.    I used to like building with 70'd vintage 74xxx TTL.
city is like lego blocks for big kids.  But as a practical matter if
you just want something to work, 21st century technology gets the job
done.

On Tue, Jan 3, 2017 at 6:49 PM, M. Simon via time-nuts
time-nuts@febo.com wrote:

--

Chris Albertson
Redondo Beach, California

Here is some nice work which was done for DCF77, Its not the same as
WWVB, but worth to have a look how it was done.

http://endorphino.de/projects/electronics/timemanipulator/index_en.html

On 2017-01-04 14:29, paul swed wrote:

--
WBW,

V.P.

Not all PC audio hardware includes such a low high frequency cutoff.

http://www.clarisonus.com/Research%20Reports/RR001-SoundCardEval/RR001-PCsoundCards.html

Based on the above review, the following cards which are still
available have a response that extends significantly above 60kHz:

http://www.m-audio.com/products/view/audiophile-192
http://www.lynxstudio.com/product_detail.asp?i=11
http://www.lynxstudio.com/product_detail.asp?i=12

On Wed, 4 Jan 2017 21:21:22 +0000 (UTC), you wrote:

Paul,
The design of the  - wwvb cheatn d-psk-r - is an excellent start. It is why I wanted a WWVB simulator. There are some points that need improvement though. To cover the full range of a VCXO the current design might require (in theory) as much as a +90 to  -90 deg phase difference between the local oscillator and WWVB. I thought that should be reduced to +22.5 to -22.5 degrees ( in theory - actual will be less because the VCXO I'm using is active from about .5V to 2.5V instead of the full 0 to 3.3V). So that adds a voltage reference (for the offset),  op amp and offset resistors to the frequency control loop.

I'm also doing full surface mount (designed for hand soldering) and rationalizing the parts values. A fast CMOS comparator (instead of the clunky LM311) etc. Power required will be +/-12V and +5. Local regulator(s) will supply parts that need 3.3V. I'm designing with low cost in mind.

I still have a lot more work to do but the general outline is more or less complete. I will publish when I get some testing done.
The AM detector is also not like any other I have seen. It may be overkill. But it is not very expensive.

Simon
 Engineering is the art of making what you want from what you can get at a profit.
I like Polywell Fusion.

On Wednesday, January 4, 2017 7:29 PM, paul swed <paulswedb@gmail.com> wrote:

SimonLike you I tend to like hardware. But today complete micros are so cheap and powerful they make life easy. Heck a bit to complex use 2 or 3. I like to follow the  "Get-er-done" philosophy.
That said search the time-nuts archive for the wwvb cheatn d-psk-r. It knows how to create the bpsk time stream aligned to wwvb then flips a BPSK switch to remove the BPSK. This allows all of the old phase tracking receivers work without modifications.I used an Arduino $8 maybe and shared all of the details and software with the group. It preserves the old AM for radios that need that modulation.So a corrected wwvb signal can be had for cheap and it works very well here on the east coast. As well as wwvb ever did.
Have fun and use whatever technology you like as you are the do-er, you get to choose.
RegardsPaulWB8TSL
On Wed, Jan 4, 2017 at 2:48 AM, Chris Albertson albertson.chris@gmail.com wrote:

You don't need to tie up a PC.    It could likely output the WWVB
signal while it was also surfing the web and reading emails.   60KHz
is NOTHING compared to displaying a you-tube video

In fact I bet your 48MHz uP could directly synthesize the signal.
Look at the ratio of 48 MHz / 60 KHz.  The uP can execute about 800
instructions during one cycle of a 60 KHz courier.     Your PC can do
a million operations during that same one cycle.

But go ahead.  I'm subscribed to another list dedicated to building
stuff with vacuum tubes.  I kind of enjoy building with that
technology.    I used to like building with 70'd vintage 74xxx TTL.
city is like lego blocks for big kids.   But as a practical matter if
you just want something to work, 21st century technology gets the job
done.

On Tue, Jan 3, 2017 at 6:49 PM, M. Simon via time-nuts
time-nuts@febo.com wrote:

--

Chris Albertson
Redondo Beach, California

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts
and follow the instructions there.

I came across this: " rpitx "  it is python software that enables a
RaspberryPi to transmit using a GPIO pin.

The links refer to using the Rpi to produce 2m Tx signal.  Rpitx seems
able to produce most modulation schemes. I have not tried it so have no
idea if it would produce your need directly.

http://zr6aic.blogspot.co.nz/2016/11/creating-2m-fm-repeater-with-raspberry.html

http://zr6aic.blogspot.co.nz/2016/10/vhf-2m-low-pass-filter-design-for.html

Cheers,

Will

On 01/05/2017 09:53 PM, M. Simon via time-nuts wrote: