Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Chris Albertson]

Lowest price I've found is BasicPCB.com  They charge $3 per square
inch for 2 layers with mask and legend.  Minimum is three boards of 1
square inch.   So you actually can place a $9 order with them.  They
are a USA based company.

They accept standard Gerber files.   This is very impotent as a few
others like PCBexpress make you use their proprietary layout software
and then you are locked into that company for production runs too.
You need a workflow that uses Gerber files.
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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[DaveH]

http://dirtypcbs.com/store/pcbs

Very happy with them.
Dave 

> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf 
> Of Dr. David Kirkby (Kirkby Microwave Ltd)
> Sent: Friday, December 09, 2016 12:07
> To: Discussion of precise time and frequency measurement; 
> Discussion of precise voltage measurement
> Subject: Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)
> 
> On 9 December 2016 at 19:58, BIll Ezell  wrote:
> > Sorry if I'm behind the times, just did a new project that 
> required a pcb,
> > and ExpressPCB is my go-to vendor for one-off boards. I 
> just noticed they
> > now provide the low-cost boards (fixed size, 3x5, quantity 
> 3) that I've
> > always ordered with silk screen and solder mask for $71. I 
> got my latest
> > boards that way and they're beautiful. No relationship to 
> them, just a happy
> > customer. You can still get the barebones boards for $51.
> 
> You also lock yourself into one vendor. There's other free software,
> like Kicad, where you can export files that many PCB manufacturers
> use. So you avoid vendor lock-in.
> 
> https://en.wikipedia.org/wiki/Vendor_lock-in
> 
> If the company goes belly up, where are you going to get any more
> boards made, without starting from scratch?
> 
> Anyway, it is a bit off topic.
> 
> Dave
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Re: [time-nuts] pcb protos

[Christopher Hoover]

+1 on Sunstone
+1 on Screaming Circuits, who will SMT the board with  consigned parts or
even do a full turnkey build.   Been happy with them on both accounts.

I don't know how many of these super cheap places will do full electrical
check  -- I want it on my personal boards.



On Fri, Dec 9, 2016 at 1:22 PM, jimlux  wrote:

> On 12/9/16 1:02 PM, Brooke Clarke wrote:
>
>> Hi John:
>>
>> Yes.  It is not at all economical to have ExpressPCB make boards the
>> final size in production.  BUT . .
>>
>
>
> I've used Sunstone (also known as PCBExpress, which *is* a bit confusing).
>
> both ExpressPCB and Sunstone also have deals with Screaming Circuits, who
> I've also used.
>
>
> Sunstone (like other places) can turn 2,4,6 layer boards around in a day,
> if you need it.  They can do up to 14 layers, although I've never used them
> for this, and I'll bet the lead time is a bit more
>
> They can also do boards on Rogers materials, if you're doing microwave
> stuff.
>
>
> There's a sort of hotbed of these quick turn firms up in Oregon.. I don't
> know why.
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[time-nuts] pcb protos

[jimlux]

On 12/9/16 1:02 PM, Brooke Clarke wrote:

Hi John:

Yes.  It is not at all economical to have ExpressPCB make boards the
final size in production.  BUT . .



I've used Sunstone (also known as PCBExpress, which *is* a bit confusing).

both ExpressPCB and Sunstone also have deals with Screaming Circuits, 
who I've also used.



Sunstone (like other places) can turn 2,4,6 layer boards around in a 
day, if you need it.  They can do up to 14 layers, although I've never 
used them for this, and I'll bet the lead time is a bit more


They can also do boards on Rogers materials, if you're doing microwave 
stuff.



There's a sort of hotbed of these quick turn firms up in Oregon.. I 
don't know why.

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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Brooke Clarke]

Hi John:

Yes.  It is not at all economical to have ExpressPCB make boards the final size in production.  BUT . . . if you have 
them make panels and cut them apart yourself it's very reasonable.  I've used many methods for cutting the boards apart 
but have settled on a 12" metal shear that cuts them as easy as cutting butter.

http://www.prc68.com/I/12InShear.shtml
There is a limit on the number of holes so you can not use holes as a way to 
snapping panels into individual boards.

Note the largest boards they make are 12 x 14".
They are in Portland, USA.

I think they are charging 34 cents/sqin (5-day) plus other charges on a per 
order and per board basis. For example:
https://www.expresspcb.com/production-service/

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.

 Original Message 
That points out a key difference in the PCB house pricing models: ExpressPCB and the Advanced Circuits $33 prototype 
are flat fee up to a size limit (for Advanced Circuits 4 x 6 inches) while others go by the square inch -- OSH Park is 
$5/in2 for three copies of two layer, and $10/in2 for three of four layer.


So for small boards, OSH Park is great but for larger boards, the price difference reduces (a 4 x 6 board ends up 
being just about the same price as Advanced Circuits).  And if you can stand the slower turnaround, the Chinese board 
houses can't be beat for any size.


John

On 12/9/2016 3:18 PM, Bob Stewart wrote:
I built my first set of boards with ExpressPCB, but they get expensive quickly if you want to make something that's 
not in their special form factor.  I use KICAD and OshPark.com to make my boards (there are other board makers).  I 
just ordered some boards that are .7" x .63" that cost $8.40 for 12.  You buy in multiples of 3, so that was actually 
$2.10 for a set of 3 times 4 sets.  Using surface mount, I was able to put an SOIC-14, an SOIC-16, an SOT23-5, three 
0805 caps, a 3 pin header, and a 5 pad connector on the board.  Something like that would be wastefully expensive on 
ExpressPCB.


Bob


   From: BIll Ezell 
  To: time-nuts@febo.com
  Sent: Friday, December 9, 2016 1:58 PM
  Subject: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

Sorry if I'm behind the times, just did a new project that required a
pcb, and ExpressPCB is my go-to vendor for one-off boards. I just
noticed they now provide the low-cost boards (fixed size, 3x5, quantity
3) that I've always ordered with silk screen and solder mask for $71. I
got my latest boards that way and they're beautiful. No relationship to
them, just a happy customer. You can still get the barebones boards for
$51. The hack I used to use was to put the component id and such on the
top copper layer as tiny text, but that was a bit of a pain for layout.
(Oops, can't put that label there, it's copper and there's a trace there
also) Really nice to be able to get real boards, even if it does end up
being ~$23/board.


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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[wb6bnq]

Dr. Dave,

That is NOT true !  I use http://www.futurlec.com/PCBService.shtml to 
handle the my ExpressPCB actions.


They are over in Asia somewhere and have been quite happy with their 
work.  They are a bit cheaper than ExpressPCB themselves.


They also will do other PCB programs and Gerber's as well.

BillWB6BNQ


Dr. David Kirkby (Kirkby Microwave Ltd) wrote:


On 9 December 2016 at 19:58, BIll Ezell  wrote:
 


Sorry if I'm behind the times, just did a new project that required a pcb,
and ExpressPCB is my go-to vendor for one-off boards. I just noticed they
now provide the low-cost boards (fixed size, 3x5, quantity 3) that I've
always ordered with silk screen and solder mask for $71. I got my latest
boards that way and they're beautiful. No relationship to them, just a happy
customer. You can still get the barebones boards for $51.
   



You also lock yourself into one vendor. There's other free software,
like Kicad, where you can export files that many PCB manufacturers
use. So you avoid vendor lock-in.

https://en.wikipedia.org/wiki/Vendor_lock-in

If the company goes belly up, where are you going to get any more
boards made, without starting from scratch?

Anyway, it is a bit off topic.

Dave
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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Bob Camp]

Hi

If you are one of those people who feel “cramped” in anything less than 6 
layers, the Chinese
are about the only way to go. There are a few houses over there that will do 6 
and 8 layer
boards at a “basement affordable” sort of price. Given the way things change 
with some of
these outfits figuring out who is doing this or that (and doing it right) can 
be a major chore.
In some cases the right answer last month is not the right answer this month …..

Bob

> On Dec 9, 2016, at 3:34 PM, John Ackermann N8UR  wrote:
> 
> That points out a key difference in the PCB house pricing models: ExpressPCB 
> and the Advanced Circuits $33 prototype are flat fee up to a size limit (for 
> Advanced Circuits 4 x 6 inches) while others go by the square inch -- OSH 
> Park is $5/in2 for three copies of two layer, and $10/in2 for three of four 
> layer.
> 
> So for small boards, OSH Park is great but for larger boards, the price 
> difference reduces (a 4 x 6 board ends up being just about the same price as 
> Advanced Circuits).  And if you can stand the slower turnaround, the Chinese 
> board houses can't be beat for any size.
> 
> John
> 
> On 12/9/2016 3:18 PM, Bob Stewart wrote:
>> I built my first set of boards with ExpressPCB, but they get expensive 
>> quickly if you want to make something that's not in their special form 
>> factor.  I use KICAD and OshPark.com to make my boards (there are other 
>> board makers).  I just ordered some boards that are .7" x .63" that cost 
>> $8.40 for 12.  You buy in multiples of 3, so that was actually $2.10 for a 
>> set of 3 times 4 sets.  Using surface mount, I was able to put an SOIC-14, 
>> an SOIC-16, an SOT23-5, three 0805 caps, a 3 pin header, and a 5 pad 
>> connector on the board.  Something like that would be wastefully expensive 
>> on ExpressPCB.
>> 
>> Bob
>> 
>> 
>>   From: BIll Ezell 
>>  To: time-nuts@febo.com
>>  Sent: Friday, December 9, 2016 1:58 PM
>>  Subject: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)
>> 
>> Sorry if I'm behind the times, just did a new project that required a
>> pcb, and ExpressPCB is my go-to vendor for one-off boards. I just
>> noticed they now provide the low-cost boards (fixed size, 3x5, quantity
>> 3) that I've always ordered with silk screen and solder mask for $71. I
>> got my latest boards that way and they're beautiful. No relationship to
>> them, just a happy customer. You can still get the barebones boards for
>> $51. The hack I used to use was to put the component id and such on the
>> top copper layer as tiny text, but that was a bit of a pain for layout.
>> (Oops, can't put that label there, it's copper and there's a trace there
>> also) Really nice to be able to get real boards, even if it does end up
>> being ~$23/board.
>> 
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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[John Ackermann N8UR]

That points out a key difference in the PCB house pricing models: 
ExpressPCB and the Advanced Circuits $33 prototype are flat fee up to a 
size limit (for Advanced Circuits 4 x 6 inches) while others go by the 
square inch -- OSH Park is $5/in2 for three copies of two layer, and 
$10/in2 for three of four layer.


So for small boards, OSH Park is great but for larger boards, the price 
difference reduces (a 4 x 6 board ends up being just about the same 
price as Advanced Circuits).  And if you can stand the slower 
turnaround, the Chinese board houses can't be beat for any size.


John

On 12/9/2016 3:18 PM, Bob Stewart wrote:

I built my first set of boards with ExpressPCB, but they get expensive quickly if you 
want to make something that's not in their special form factor.  I use KICAD and 
OshPark.com to make my boards (there are other board makers).  I just ordered some boards 
that are .7" x .63" that cost $8.40 for 12.  You buy in multiples of 3, so that 
was actually $2.10 for a set of 3 times 4 sets.  Using surface mount, I was able to put 
an SOIC-14, an SOIC-16, an SOT23-5, three 0805 caps, a 3 pin header, and a 5 pad 
connector on the board.  Something like that would be wastefully expensive on ExpressPCB.

Bob


   From: BIll Ezell 
  To: time-nuts@febo.com
  Sent: Friday, December 9, 2016 1:58 PM
  Subject: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

Sorry if I'm behind the times, just did a new project that required a
pcb, and ExpressPCB is my go-to vendor for one-off boards. I just
noticed they now provide the low-cost boards (fixed size, 3x5, quantity
3) that I've always ordered with silk screen and solder mask for $71. I
got my latest boards that way and they're beautiful. No relationship to
them, just a happy customer. You can still get the barebones boards for
$51. The hack I used to use was to put the component id and such on the
top copper layer as tiny text, but that was a bit of a pain for layout.
(Oops, can't put that label there, it's copper and there's a trace there
also) Really nice to be able to get real boards, even if it does end up
being ~$23/board.


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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Bob Stewart]

I built my first set of boards with ExpressPCB, but they get expensive quickly 
if you want to make something that's not in their special form factor.  I use 
KICAD and OshPark.com to make my boards (there are other board makers).  I just 
ordered some boards that are .7" x .63" that cost $8.40 for 12.  You buy in 
multiples of 3, so that was actually $2.10 for a set of 3 times 4 sets.  Using 
surface mount, I was able to put an SOIC-14, an SOIC-16, an SOT23-5, three 0805 
caps, a 3 pin header, and a 5 pad connector on the board.  Something like that 
would be wastefully expensive on ExpressPCB.

Bob 


  From: BIll Ezell 
 To: time-nuts@febo.com 
 Sent: Friday, December 9, 2016 1:58 PM
 Subject: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)
   
Sorry if I'm behind the times, just did a new project that required a 
pcb, and ExpressPCB is my go-to vendor for one-off boards. I just 
noticed they now provide the low-cost boards (fixed size, 3x5, quantity 
3) that I've always ordered with silk screen and solder mask for $71. I 
got my latest boards that way and they're beautiful. No relationship to 
them, just a happy customer. You can still get the barebones boards for 
$51. The hack I used to use was to put the component id and such on the 
top copper layer as tiny text, but that was a bit of a pain for layout. 
(Oops, can't put that label there, it's copper and there's a trace there 
also) Really nice to be able to get real boards, even if it does end up 
being ~$23/board.

-- 
Bill Ezell
--
The day Microsoft makes something that doesn't suck
will be the day they make vacuum cleaners.
Or maybe Windows 10.

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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Brooke Clarke]

Hi Bill:

It's their Mini Board Pro service and you get 3 each 2-layer boards each 3.8 x 2.5" with solder mask (great for SMT) and 
silk screen top side labels for $61.

https://www.expresspcb.com/miniboard-pro/

If you get this service some caution is needed regarding the solder mask since it's possible to have the mask where you 
were expecting to see metal.


Also note they have free schematic software that can be used to check the nodes 
on the board layout.

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.

 Original Message 
Sorry if I'm behind the times, just did a new project that required a pcb, and ExpressPCB is my go-to vendor for 
one-off boards. I just noticed they now provide the low-cost boards (fixed size, 3x5, quantity 3) that I've always 
ordered with silk screen and solder mask for $71. I got my latest boards that way and they're beautiful. No 
relationship to them, just a happy customer. You can still get the barebones boards for $51. The hack I used to use 
was to put the component id and such on the top copper layer as tiny text, but that was a bit of a pain for layout. 
(Oops, can't put that label there, it's copper and there's a trace there also) Really nice to be able to get real 
boards, even if it does end up being ~$23/board.




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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Bob Camp]

Hi

The bottom line has always been that the outfits in China are the cheaper 
source for boards.
That said, right now, Advanced Circuits will sell you a single piece of a 
double sided board
for $33. It’s a “full feature” board with solder mask, silk screen, and a 3 day 
fab time. I don’t 
use their free software, but have always been quite happy with their boards.

Bob
 
> On Dec 9, 2016, at 2:58 PM, BIll Ezell  wrote:
> 
> Sorry if I'm behind the times, just did a new project that required a pcb, 
> and ExpressPCB is my go-to vendor for one-off boards. I just noticed they now 
> provide the low-cost boards (fixed size, 3x5, quantity 3) that I've always 
> ordered with silk screen and solder mask for $71. I got my latest boards that 
> way and they're beautiful. No relationship to them, just a happy customer. 
> You can still get the barebones boards for $51. The hack I used to use was to 
> put the component id and such on the top copper layer as tiny text, but that 
> was a bit of a pain for layout. (Oops, can't put that label there, it's 
> copper and there's a trace there also) Really nice to be able to get real 
> boards, even if it does end up being ~$23/board.
> 
> -- 
> Bill Ezell
> --
> The day Microsoft makes something that doesn't suck
> will be the day they make vacuum cleaners.
> Or maybe Windows 10.
> 
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Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 9 December 2016 at 19:58, BIll Ezell  wrote:
> Sorry if I'm behind the times, just did a new project that required a pcb,
> and ExpressPCB is my go-to vendor for one-off boards. I just noticed they
> now provide the low-cost boards (fixed size, 3x5, quantity 3) that I've
> always ordered with silk screen and solder mask for $71. I got my latest
> boards that way and they're beautiful. No relationship to them, just a happy
> customer. You can still get the barebones boards for $51.

You also lock yourself into one vendor. There's other free software,
like Kicad, where you can export files that many PCB manufacturers
use. So you avoid vendor lock-in.

https://en.wikipedia.org/wiki/Vendor_lock-in

If the company goes belly up, where are you going to get any more
boards made, without starting from scratch?

Anyway, it is a bit off topic.

Dave
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[time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

[BIll Ezell]

Sorry if I'm behind the times, just did a new project that required a 
pcb, and ExpressPCB is my go-to vendor for one-off boards. I just 
noticed they now provide the low-cost boards (fixed size, 3x5, quantity 
3) that I've always ordered with silk screen and solder mask for $71. I 
got my latest boards that way and they're beautiful. No relationship to 
them, just a happy customer. You can still get the barebones boards for 
$51. The hack I used to use was to put the component id and such on the 
top copper layer as tiny text, but that was a bit of a pain for layout. 
(Oops, can't put that label there, it's copper and there's a trace there 
also) Really nice to be able to get real boards, even if it does end up 
being ~$23/board.


--
Bill Ezell
--
The day Microsoft makes something that doesn't suck
will be the day they make vacuum cleaners.
Or maybe Windows 10.

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Re: [time-nuts] SiLabs5351C

[James Robbins]

Hello Peter,

 

I found a note on Time-Nuts from you back on November 18, 2014 referencing
the use of "SiLabs5351C" to get 10 MHz from a 15 MHz oscillator.  Your
Dropbox links don't work anymore.  Would you have any further information
you could share about your use of it?  Many thanks.

 

Jim Robbins

N1JR

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[time-nuts] Performance of TDC7200

[Li Ang]

I've done some tests with TDC7200 and TDC_GP22 few months 
ago.(https://www.febo.com/pipermail/time-nuts/2016-May/098170.html)


Here is the performance test of my recent board.



http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/schematic.pdf
http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/freqcntv6.0.jpg


The "analog front end" is 74lvc1g04/nc7sz125. 3 TDC7200s are on the board. Only 
TI mode is tested at the moment.(the truth is I forgot to connect the SPI port 
to FPGA .., I need to reuse the config ports to implement a bidirectional 
SPI to read the counters in FPGA)
DUT and REF are from a homebrew distribution amp( 
http://www.qsl.net/b/bi7lnq/distribution_amp/v1.5/10M_distributor.pdf), the 
source is a FE180 OCXO.


1) the noise of 74LVC and NC7 are different.
2) the performance of my counter in TI mode is almost the same as the Agilent 
53220A
http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/nc7sz125_74lvc1g04_53220a.png


I also tried to measure 3 OCXOs at the same time. FE180, OCXO8663, free running 
TBOLT
http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/freqcnt_v6_20161209.png
http://www.qsl.net/b/bi7lnq/Projects/freqcnt6.0/data/20161209/freqcnt_v6_20161209_3corneredhat.png


TODO list:
1) web based interface, calculate and show *DEVs with javascript on Chrome 
browser
2) front end experiments




Regards


Li Ang / BI7LNQ
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Re: [time-nuts] Totally unrelated, but..

[David G. McGaw]

One has to be very careful with LDOs.  As we say in applications, 
RTFDS.  :-)  The output capacitor often needs a finite ESR (effective 
series resistance).  A too-large ceramic cap WILL make them oscillate.  
I have noticed that they are used in some GPSDOs.


David


On 12/8/16 11:39 AM, Van Horn, David wrote:

Yes, I hit one of those. I forget the frequency other than around 1 MHz, but it 
was pretty warm when it shouldn't have been, and it was several volts amplitude.

This thing I'm chasing is much more subtle.

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris
Sent: Wednesday, December 7, 2016 1:57 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Totally unrelated, but..

I don't think so.  I first ran into a batch of LM340-5's that were excellent 
oscillators back in the 1970's... long before counterfeiting was even remotely 
possible.

The symptom is the regulator puts out only 4.5 out of 5V.

LM309's were, however, totally immune.

Usually, I had to be really bad to make it happen, things like using clip leads 
between the power supply and load with the LM340-5 dangling in between.

The answer is as simple as a couple of 0.1uf ceramic caps soldered right at the 
input and ground, and the output and ground pins.

LDO (low dropout) regulators are very susceptible to oscillation.  They need to 
have a couple of hundred uf of good quality capacitance right on the input and 
output leads.  Where people usually get in trouble, is in not knowing that 
electrolytic capacitors lose most of their capacitance as the temperature 
starts hovering around 0C.

The circuit works great on the bench, but fails when out hanging on a light 
pole...

-Chuck Harris

Joe Leikhim wrote:

Could the low noise parts actually be counterfeit, relabeled as such?

Is the circuit the regulator feeds sensitive to a narrow band of
voltage that the "good regulator" is outside of?

Try replacing the regulator with a battery supply and resistor divider
to attain the working voltage. Move the voltage around. A good
potentiometer and stiff filter capacitors are recommended so as not to introduce 
"pot noise".

Is something corrupting your test procedure?  I had a circuit that
misbehaved due to floating logic pins reacting to static electricity
on the work bench. Another time a diode was photosensitive.




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