Re: RD16HHF1 in the uBITX #ubitx

Vince Vielhaber
 

Yeah, a pound of Kester last month was $25.10 + $7 shipping.

Vince.

On 02/21/2018 04:54 PM, Michael Hagen wrote:
He is not selling supplies anymore.

This is where he suggest getting supplies. CML Supply. They got lots
of good stuff and the prices look good.

Have you bought a pound of solder lately!

I am still trying to get solder paste down without a mess. I can't get
it thru syringes so far.

Mike, WA6ISP


https://www.cmlsupply.com/kester-ep256-lead-solder-paste-63-37-syringe-dispenser/



On 2/21/2018 1:35 PM, Eric KE6US wrote:

Sorry. I got lazy.

http://kd5ssj.com/solderpaste/smt-tools-and-process

Very informative. I haven't tried the beverage warmer he talks about
to preheat the board. Good idea, though. I usually just wave the heat
gun around a foot or so above the board to warm it up., but the
beverage warmer is a more positive step that encourages doing it right.

Some people use a toaster oven for reflow and have developed
temperature profiles matching commercial production techniques. That's
the right way to do it, and backed up by science, but bench work
doesn't always require the same techniques that commercial production
requires. I never bought anything from Sony that incorporated dead bug
construction, but I'm sure their engineers and techs do initial proof
of concept that way.

Fun call on CW. I like it.

Eric KE6US


On 2/21/2018 11:17 AM, K5ESS wrote:

Eric,

Couldn’t find your earlier link to “Cash’s video”. Could you re-post.

Thanks

Mike

K5ESS



*From:*BITX20@groups.io [mailto:BITX20@groups.io] *On Behalf Of *Eric
KE6US
*Sent:* Wednesday, February 21, 2018 12:07 PM
*To:* BITX20@groups.io
*Subject:* Re: [BITX20] RD16HHF1 in the uBITX



Looks fine. Mine is from Michael's rated at 360w. It was $20. WalMart
might even be cheaper. They're probably all nearly identical. Mine
looks like the one you show except for packaging details. BTW, it's
super for heat shrink tubing too.

You control the heat with the distance from the piece. I start out
about a foot away to get the board warmed up to a point where I don't
want to touch it, Keep the end moving. Watch Cash's video that I link
to earlier. It's really that easy.

Don't get too close to the part while the solder paste is still grey.
There's a point where the solder paste starts getting a little glossy
and slick. You can blow the part right off the pads if you get too
aggressive. For that matter, I often tape smaller PCBs down as they
can scoot around from the air flow too. Then it's magic. The solder
turns silver, the part aligns itself right on the pads better than
you did, and it's a thing of beauty.

On very tiny parts, say ones with 0.5 pitch pins, you can get solder
bridges. Don't worry about them. A light touch with solder wick and a
soldering iron and they disappear leaving the part perfectly soldered
in place. On many tiny parts with lots of legs, I just lay down a
running blob of solder that shorts all the pins together, then wick
up the excess. I did about a dozen AD9850s that way. All perfect.

I understand some guys have tremors and other things that would make
SMT difficult. It takes a steady hand to place the parts but not
nerves of steel. I suspect anyone who can walk from the kitchen to
their workbench with a full cup of coffee without spilling any could
manage the larger SMTs without difficulty.

SMTs open up a whole new world of kit building and homebrew
possibilities. They aren't limiting our abilities at all. We're doing
that to ourselves.

Eric KE6US



On 2/20/2018 9:21 PM, VE7WQ wrote:

Thank you Eric,



What do you think about this heat gun on eBay?

110V 300W Hot Air Gun Hand Hold Mini Heat Gun for Embossing Heat
Tool $10.76

https://tinyurl.com/y7vrbfvt

Or should I buy a $20 embossing tool (heat gun) from WalMart or
any craft store ?



73! George

VE7WQ



Tuesday, February 20, 2018, among other things you wrote:

EK> A syringe, a small tweezer to place the parts, solder paste
and a $20

EK> embossing tool (heat gun) from WalMart or any craft store. It
makes the

EK> 20-QFN or any other SMT easy.


--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...

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