Hot air soldering...

[sinclairuser]

add an aspirin

is that to help with the headaches when soldering smt components?,lol.

[nejdet]

Не бих препоръчал да слагате аспирин в колофона. Има киселинно действие и впоследствие разрушава електрониката!

[David_1]

is that to help with the headaches when soldering smt components?,lol.

100% no clue the rosin I bought goes from dust up to sugar lump sizes... But still not done anything with it.. Must stop late night Ebay buying !

[Qiaozhi]

Не бих препоръчал да слагате аспирин в колофона. Има киселинно действие и впоследствие разрушава електрониката!

Please read the forum rules -> Basic Rules of the Forums
and make your posts in English.

[nejdet]

Не бих препоръчал да слагате аспирин в колофона. Има киселинно действие и впоследствие разрушава електрониката!

I would not recommend putting aspirin in rosin. It has an acidic effect and subsequently destroys the electronics! PS the mistake is mine for which I apologize

[David_1]

I would not recommend putting aspirin in rosin. It has an acidic effect and subsequently destroys the electronics! PS the mistake is mine for which I apologize

Nothing to apologize for English is my fist language ... only language ! but we need people from everywhere not sure if the aspirin thing was just a joke anyway We need a little humour too

[ivconic]

The thin protective coating of the aspirin pill is composed of acetylisalicylic acid.
Acetasalicylic acid instantly dissolves varnish on wires when heated.
Whenever I had to remove part of the insulation on the lacquered copper wire; I used an aspirin pill.
By placing the pill on the desk, I put the part of the wire I want to clean from the insulation over the middle of the pill.
And with the tip of a soldering iron on which there is very little tin, I abruptly heat that part of the wire.
In this way, the varnish insulation is removed at the same time and the wire is very well tinned.
Maybe the suggestion is related to aspirin pills in that direction?

[Carl-NC]

The thin protective coating of the aspirin pill is composed of acetylisalicylic acid.
Acetasalicylic acid instantly dissolves varnish on wires when heated.
Whenever I had to remove part of the insulation on the lacquered copper wire; I used an aspirin pill.
By placing the pill on the desk, I put the part of the wire I want to clean from the insulation over the middle of the pill.
And with the tip of a soldering iron on which there is very little tin, I abruptly heat that part of the wire.
In this way, the varnish insulation is removed at the same time and the wire is very well tinned.
Maybe the suggestion is related to aspirin pills in that direction?

True, I've used that trick as well.

[dbanner]

What a waste of an aspirin!

[dbanner]

I'll demonstrate another trick.

I've got a whole bag of aspirin that was prescribed to me after doing surgery. The little baby ones.

It is what you might refer to as " slow release".

[dbanner]

Hence the coating.

[ivconic]

This should be instructive and educative ...
I soldered all the parts to the SMD board for the SMW detector.
First turn on ... it doesn't work! ?? And I've made at least 200 so far ... never a more serious problem.
The strange thing is that the human brain is always prone to complications.
And somehow I always forget about that phenomenon.
So I started fantasizing and assuming it was some complicated issue on board.
There are several reasons for this. I put all the used components.
SMD transistors have some dumb tags, so I just checked them simple and didn't measure the characteristics.
SMD unpolarized capacitors are also all of questionable condition.
I have a capacitor meter but I don't have a handy probe for SMD components.
So I was looking for a fault for a couple of days, with completely wrong assumptions.
I have a new two-channel oscilloscope, but I literally hated turning it on, calculating that I would easily find what the problem was, without need to use it.
After a few days of fooling around ... I realized the devil had taken all the joke ...
Finally I turned on the oscilloscope ...
The pictures speak for themselves ...

1) TX Out -
2) RX signal with first LF347 on board -
3) RX signal with first LF347 removed from board -
4) Situation under the removed LF347 -
5) Again -

Well...
That's how I payed the price for the initial steps in working with a hot air soldering gun, gaining the first practical experiences.
Experimenting with cheap liquid tin, flux ... nope!
In addition, in such works, liquid tin is unnecessary. I manage to solder the ic circuit quite well and easily with an ordinary soldering iron and tin wire.

[gurdal]

hello master ivica,
on samsung gsm service
while working,
I was using a very high quality white cream cake.Soldering perfectly with normal soldering iron or hot air.
I'll post if I find the brand.
also there is jumper on pcb,
What is the reason?
do you have smw latest status video
I couldn't run grond balance

[ivconic]

hello master ivica,
on samsung gsm service
while working,
I was using a very high quality white cream cake.Soldering perfectly with normal soldering iron or hot air.
I'll post if I find the brand.
also there is jumper on pcb,
What is the reason?
do you have smw latest status video
I couldn't run grond balance

Two jumpers. Without them you have standard SMW audio.
With two jumpers shorted; you have "Bell tone" audio, similar to Garrett's audio when hits nice target.
...
Yesterday i discovered a mistake on pcb. 100pF capacitor is wired wrong. My mistake.
But i am happy it is only one!

Easy to fix.
Just lift one side (right side) from the pcb and with piece of wire connect that side to where 392 capacitor and 3k9 resistor are connected.

It is wrong connected to Phase trimmer.
I don't know how you are testing GEB, maybe with ferrite?
If so; than you should know that it can not fully reject ferrite when Disc is at 0. (it actually can reject ferrite with perfectly matched coil, but in 90% of cases coil is not matched perfectly)
But in real life you don't need it to reject ferrite at all. Use piece of ancient Roman ceramics instead to adjust the GEB.
Adjust Disc at ... say "2" or "3" (still accepts irons) and than adjust GEB trimmer and potentiometer range to suits you.
It will than fully reject iron at "6" on Disc pot.
Sorry for the mistake, I haven't made it since the other day, so i couldn't warn you about it.

[ivconic]

It is obvious that I sacrificed this pcb for the purpose of training with a hot air soldering iron.
It is so greasy and dirty I can't look at it. I have never done such dirty and messy work.
I'm thinking of removing all the components, washing it in nitro thinner and re-soldering new components...