2017-08-09, 08:42
Hi Breitling,
two answers: I took a quick lock at the signal from your station, and the major noise is at 15-16 kHz, so this cannot be removed by the filters. On the other hand, the smaller peak at 66 kHz can be suppressed.
I used the following procedure to solder the filter ICs: First, I applied a bit of flux with a pen dispenser on the legs of the filters and on the pads on the board. The soldering iron had a flat tip of 4 mm width, like the tip of an old screwdriver. This tip then covers all 4 legs on one side of the package. The soldering iron was on a middle temperature, not on max and I wetted its tip only with a small amount of solder. Then I used a pincer to hold the filter at the two sides were there are no legs and placed them exactly on the pads on the board and pressed the legs on one side down with the flat tip of the soldering iron. The solder on the pads melted immediately and the legs moved down a bit. I then withdrew the soldering iron sideways, so there were to solder bridges between the legs and waited of few seconds until the solder had cooled down. Then I rotated the board and soldered the four legs on the other side. In this way I did'nt need a very fine tip, the broad one did even better, it allowed to solder all four legs in one go. The amount of solder which is already on the pads is sufficient to fix the filters and connect them.
I should add that I am very short-sighted, so without my glasses I can see very good at short distances and I did'nt need a magnifying glass in order to control the whole operation. .
two answers: I took a quick lock at the signal from your station, and the major noise is at 15-16 kHz, so this cannot be removed by the filters. On the other hand, the smaller peak at 66 kHz can be suppressed.
I used the following procedure to solder the filter ICs: First, I applied a bit of flux with a pen dispenser on the legs of the filters and on the pads on the board. The soldering iron had a flat tip of 4 mm width, like the tip of an old screwdriver. This tip then covers all 4 legs on one side of the package. The soldering iron was on a middle temperature, not on max and I wetted its tip only with a small amount of solder. Then I used a pincer to hold the filter at the two sides were there are no legs and placed them exactly on the pads on the board and pressed the legs on one side down with the flat tip of the soldering iron. The solder on the pads melted immediately and the legs moved down a bit. I then withdrew the soldering iron sideways, so there were to solder bridges between the legs and waited of few seconds until the solder had cooled down. Then I rotated the board and soldered the four legs on the other side. In this way I did'nt need a very fine tip, the broad one did even better, it allowed to solder all four legs in one go. The amount of solder which is already on the pads is sufficient to fix the filters and connect them.
I should add that I am very short-sighted, so without my glasses I can see very good at short distances and I did'nt need a magnifying glass in order to control the whole operation. .
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