Topics

Microphony

Peter Russell <peter.russell@...>
 

Cured!
turned out to be C50 in the audio pre amp.
replaced it with a leaded electrolytic.

A little tip - for those who need it!
If you know that you are going to replace a smd capacitor or resistor, I find the easiest way to remove them is to take a pair of small cutters and cut the component in half.
Then, with a pair of tweezers, it's easy to unsolder the two ends.

Peter G8FWY

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Jerry Gaffke
 

I've never done it that way, nipping a cold SMD part with a pair of cutters..
Mechanical stresses would be considerable, this never separates copper pad from board?

I generally use two soldering irons, heat both ends simultaneously.
Then pick the part up using the two irons like tweezers.


On Tue, Jan 1, 2019 at 04:06 AM, Peter Russell wrote:
Cured!
turned out to be C50 in the audio pre amp.
replaced it with a leaded electrolytic.

A little tip - for those who need it!
If you know that you are going to replace a smd capacitor or resistor, I find the easiest way to remove them is to take a pair of small cutters and cut the component in half.
Then, with a pair of tweezers, it's easy to unsolder the two ends.

Peter G8FWY

Bob Lunsford <nocrud222@...>
 

I saw a hint about removing SMD devices some time ago.

If you do not have any tools for removing them, here is
the hint:

First, use a solder-sucker or wicking and remove any
excess solder. Then loop a #28 or so enameled wire under
the device and while heating the end, pull the wire out which
causes a gap at the end where heat is applied. Then you
can heat the other end and it will be easy to remove the
device.

I also wondered about snapping the device in two but was
worried that the stress could lift the pad/s. So far I have not
found it necessary to remove any SMD device but now you
have another suggested method for doing it.

Bob — KK5$


--------------------------------------------

On Tue, 1/1/19, Peter Russell <peter.russell@...> wrote:

Subject: [BITX20] Microphony
To: BITX20@groups.io
Date: Tuesday, January 1, 2019, 7:06 AM

Cured!
turned out to be C50 in the audio pre
amp.
replaced it with a leaded
electrolytic.

A little tip - for those who need it!
If you know that you are going to
replace a smd capacitor or resistor, I
find the easiest way to remove them is
to take a pair of small cutters
and cut the component in half.
Then, with a pair of tweezers, it's
easy to unsolder the two ends.

Peter G8FWY

---
This email has been checked for viruses
by AVG.
https://www.avg.com

iz oos
 

I would not break it in two, my Weller has a tip that If used slopes can touch both sides of the SMD. I just put the iron in the middle of the SMD a slight pressure and it goes away, it is that easy. If necessary adding solder also helps. It depends on the size of the smt. The ones used in ubitx are rather small and easy to remove.


Il 02/gen/2019 01:16, "Bob Lunsford via Groups.Io" <nocrud222=yahoo.com@groups.io> ha scritto:
I saw a hint about removing SMD devices some time ago.

If you do not have any tools for removing them, here is
the hint:

First, use a solder-sucker or wicking and remove any
excess solder. Then loop a #28 or so enameled wire under
the device and while heating the end, pull the wire out which
causes a gap at the end where heat is applied. Then you
can heat the other end and it will be easy to remove the
device.

I also wondered about snapping the device in two but was
worried that the stress could lift the pad/s. So far I have not
found it necessary to remove any SMD device but now you
have another suggested method for doing it.

Bob — KK5$


--------------------------------------------
On Tue, 1/1/19, Peter Russell <peter.russell@...> wrote:

 Subject: [BITX20] Microphony
 To: BITX20@groups.io
 Date: Tuesday, January 1, 2019, 7:06 AM

 Cured!
 turned out to be C50 in the audio pre
 amp.
 replaced it with a leaded
 electrolytic.

 A little tip - for those who need it!
 If you know that you are going to
 replace a smd capacitor or resistor, I
 find the easiest way to remove them is
 to take a pair of small cutters
 and cut the component in half.
 Then, with a pair of tweezers, it's
 easy to unsolder the two ends.

 Peter G8FWY

 ---
 This email has been checked for viruses
 by AVG.
 https://www.avg.com








Bob Lunsford <nocrud222@...>
 

There are soldering irons that can change the tips easily.
The tips can be obtained that are special for different
purposes. One may be wide enough to cut a small section
out and use it for bridging the SMD and it also makes the
removal easy.

The wire loop to remove the solder is for those who do not
have such special soldering irons. I also have a Weller
iron that can be bought at Lowes for $10-$15 that has dual
heat of 30/130W and is model TB100 and a chisel tip can
be obtained in electronic catalogs. Perhaps Lowes has the
tip but I did not check. Problem is, though, if you modify the
tip to cut out a U-Section so it will bridge an SMD device,
plating on the tip is also removed and this will promote
deterioration of the tip. However, the width of the tip may
be correct for removing an SMD device but I would only do
this if I did not plan to use that SMD device again unless
done quickly so the heat does not cause damage.

I will check at Lowes tomorrow to see if a kit of tips for the
iron is available. The TB100 is what I use mostly because
it is so convenient and at 30W, it is the proper size for most
things I solder. I have other irons, though, for very delicate
soldering but the TB100 is my prefered soldering iron. It is
pistol grip, though, and some prefer a pencil style.

Bob — KK5R

--------------------------------------------

On Wed, 1/2/19, iz oos <and2oosiz2@...> wrote:

Subject: Re: [BITX20] Microphony
To: BITX20@groups.io
Date: Wednesday, January 2, 2019, 3:14 AM

I would not break it
in two, my Weller has a tip that If used slopes can touch
both sides of the SMD. I just put the iron in the middle of
the SMD a slight pressure and it goes away, it is that easy.
If necessary adding solder also helps. It depends on the
size of the smt. The ones used in ubitx are rather small and
easy to remove.

Il 02/gen/2019 01:16,
"Bob Lunsford via Groups.Io" <nocrud222=yahoo.com@groups.io>
ha scritto:
I saw a
hint about removing SMD devices some time ago.



If you do not have any tools for removing them, here is

the hint:



First, use a solder-sucker or wicking and remove any

excess solder. Then loop a #28 or so enameled wire under

the device and while heating the end, pull the wire out
which

causes a gap at the end where heat is applied. Then you

can heat the other end and it will be easy to remove the

device.



I also wondered about snapping the device in two but was

worried that the stress could lift the pad/s. So far I have
not

found it necessary to remove any SMD device but now you

have another suggested method for doing it.



Bob — KK5$





------------------------------ --------------

On Tue, 1/1/19, Peter Russell <peter.russell@...
> wrote:



 Subject: [BITX20] Microphony

 To: BITX20@groups.io

 Date: Tuesday, January 1, 2019, 7:06 AM



 Cured!

 turned out to be C50 in the audio pre

 amp.

 replaced it with a leaded

 electrolytic.



 A little tip - for those who need it!

 If you know that you are going to

 replace a smd capacitor or resistor, I

 find the easiest way to remove them is

 to take a pair of small cutters

 and cut the component in half.

 Then, with a pair of tweezers, it's

 easy to unsolder the two ends.



 Peter G8FWY



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 This email has been checked for viruses

 by AVG.

 https://www.avg.com

Alf Baranda
 

Hello to all.
A few days ago I also did that work because my Bitx40 also suffered from a strong microphone that was born in the AF Amp and surroundings.
I removed the ceramic capacitors C115 and C116 in the AF Amp circuit and also C120 and C122 in the MIC Amp circuit.
All of them were replaced by 1uF/35V Electrolytic capacitors and the annoying effect disappeared.
It is very important to respect the correct polarity of the electrolitic caps.
To remove the original caps, simply apply a large amount of tin on both sides at the same time to remove it, then dislodge the tin with the desoldering braid to place the new one.
I hope I have explained it correctly, English is not my native language.
Good luck and enjoy it.