[time-nuts] WWVB teensy BPSK early experiments

[Bob kb8tq]

Hi

The gizmo you want is a hot air rework tool. They are not all that expensive
( < $200 for a fancy one, quite a bit less for a simple one). They normally
come with a bunch of tips. That lets you “focus” the heat on the part you want 
to pull.

One of an infinite number, randomly chosen:

https://www.amazon.com/gp/product/B006FA481G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 <https://www.amazon.com/gp/product/B006FA481G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1>

Bob

> On Oct 31, 2020, at 8:42 PM, paul swed <paulswedb at gmail.com> wrote:
> 
> Jim
> Thanks for the details. I took a serious look at popping the xtal out and
> am afraid its a bit beyond me since there are 4 pads that need to be
> heated. I have worked on very small stuff under the microscope. But this
> seems problematic. I sort of thought all the bits would get upset. No free
> lunch.
> No matter not popping the xtal. Mainly because if anyone else did want to
> build the magical solution it would be as bad as soldering lots of chips.
> Super fine wires to very small pads.
> But at least at the moment perhaps thats not critical to developing
> something.
> I did tinker with delay and will need to use a scope at this point to see
> the effects.
> Regards
> Paul.
> 
> 
> On Sat, Oct 31, 2020 at 7:35 PM jimlux <jimlux at earthlink.net> wrote:
> 
>> On 10/31/20 11:42 AM, Bob kb8tq wrote:
>>> Hi
>>> 
>>> …..errr…..
>>> 
>>> Can you pull the clock oscillator off the Teensy board? (Yes, the
>> soldering
>>> iron would be involved).
>>> 
>>> Will the clock input to the MCU accept something like 10 MHz? If so
>> solder
>>> on a cable ….
>>> 
>>> At that point whatever the Teeny does is locked to the 10 MHz. If that
>> comes
>>> from one of the $3 eBay OCXO’s, steer that with a DAC output … now you
>>> have a WWVB GPSDO.
>>> 
>>> Indeed, if the Teensy needs 28 MHz, then the OCXO will not be quite as
>> cheap.
>>> 
>>> Bob
>>> 
>> 
>> I've tried this - It will run just fine, but *all the UART and USB
>> speeds change*.  So, basically, the USB stops working, and you need to
>> set your serial port to something like 112.8 * 10/28 (and it takes a bit
>> of fiddling to get it to work right)..  I sort of cheated, and switched
>> back and forth - signal generator to 28MHz, load and debug software,
>> start it, then switch generator to 10 MHz.
>> 
>> And of course, all the functions that are time based, like delay() are
>> the wrong length.
>> 
>> One could probably figure out a relatively few patches to the
>> Teensyduino code base that would fix all this (clock rate is a variable
>> - you can run the teensy at multiple clock rates, even with the same
>> crystal)
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.