Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

GFS-GPSDOs/info > > From: Bob Albert via time-nuts <time-nuts@febo.com> > To: Discussion of precise time and frequency measurement < > time-nuts@febo.com> > Sent: Thursday, August 18, 2016 8:49 PM > Subject: Re: [time-nuts] Subject: Re: Working with SMT par

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

groups.yahoo.com/neo/groups/GFS-GPSDOs/info       From: Bob Albert via time-nuts <time-nuts@febo.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, August 18, 2016 8:49 PM Subject: Re: [time-nuts] Subject: Re: Working with SMT parts (

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

nuts <time-nuts@febo.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, August 18, 2016 8:49 PM Subject: Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert) I don't care about lead-free since I am not manufacturing,

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

On 8/18/2016 2:41 PM, Bob Albert via time-nuts wrote: > Well I have found some Chinese sources of 42 - 50 grams on ebay for around > $3. Is this the right stuff? The brand is Mechanics. > > Bob Best and Mechanic brand from China in small (50 gr) containers seems to work fine. The small

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

I don't care about lead-free since I am not manufacturing, just repairing or building or experimenting.  But there seems to be more than one way to view this stuff.  Yes, it might be expired, but some say that's not a major issue.  I can't justify the prices asked by US distributors, especially

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

The Chinese are certainly using a lot of solder paste, so they are a source. I tend to buy mine from Mouser, Digikey, TekSource, places like that. The last stuff I bought was made by Kester, and came from TekSource. The only problem with using the real sources is in the summer, they will pack

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Uhmmm, I buy it new, and expire it myself... blush. -Chuck Harris Bob Albert via time-nuts wrote: > So where do you get this expired paste? I have tried a few searches but no > luck. > Bob ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

So where do you get this expired paste?  I have tried a few searches but no luck. Bob On Thursday, August 18, 2016 12:00 PM, Chuck Harris wrote: I have had similar experience with well expired paste. I just don't worry about it. The issue is the solder is ground

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Well I have found some Chinese sources of 42 - 50 grams on ebay for around $3.  Is this the right stuff?  The brand is Mechanics. Bob On Thursday, August 18, 2016 12:11 PM, Bob Albert wrote: So where do you get this expired paste?  I have tried a few searches but

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

I have had similar experience with well expired paste. I just don't worry about it. The issue is the solder is ground to such a fine powder that it has a huge surface area to oxidize. As long as you keep the air off, and refrigerate the paste, it seems to go forever. Oh, and I only use

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Ah Steve, that's good info!  Now where does one buy expired solder paste?  And what's the proper name for it - solder paste searches mostly come up with just flux. Bob On Thursday, August 18, 2016 2:25 AM, Steve Wiseman wrote: On 18 August 2016 at 07:07, Bob

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

On 18 August 2016 at 07:07, Bob Albert via time-nuts wrote: > I didn't use the liquid solder because I didn't have any and it doesn't keep > very long. That's not really the case. It may change consistency so that it behaves a little differently and fouls up automated

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Jim, that's the exact one I built!  I rechecked and the rise time is about 2 ns, not longer as I previously reported.  Not only do I have a new piece of test gear but I have gotten some SMT experience.  Previously I have removed chips but this is the first time I have installed one.  I didn't

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Hi again, The cable impedance measurement was in a different video (linked below) but it can use the same HC14 TDR as in the first video. The concept is to just put a pot on the end of the cable and adjust it until the reflection goes away. Simple! https://www.youtube.com/watch?v=Il_eju4D_TM

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

Hi Bob, Take a look at this nice simple little one chip "TDR" and lesson on how to use it to measure cable length and cable impedance. It uses a single AC14 (can use a DIP so no SMD needed) and gives a nice crisp 2 or 3 ns rise. The AC family is nice fast logic and has been used in many Time-Nuts