Don,
I have a strong suspicion that the solder pad did not receive enough
heat initially. It can happen that the solder looks nice and shiny, but
the solder does not have good flow onto the pad. I have seen that
condition more times than I would like. It is the result of too low a
soldering temperature.
A word to potential builders - keep the soldering iron temperature
greater than 700 deg F (750 is better). You will not damage anything if
the soldering temperature is 800 deg F or below *and* the soldering time
is kept short - contrary to popular belief, damage *will* occur with a
low iron temperature applied for a long period of time. Also use a
small diameter solder so you can control the amount and watch as the
thru-hole is heated, it will wick a bit of solder into the hole when it
receives adequate heat, but too much applied solder will mask that
process and can hide a bad solder joint.
73,
Don W3FPR
[EMAIL PROTECTED] wrote:
A few weeks back I wrote that I was experiencing a most unusual noise
problem. I had hoped that someone else might have had the same problem and would
have the answer. This didn't happen.
The noise was noticeable when the volume control and RF Gain were at minimum
and even the antenna disconnected.
I want to thank Gary, KI4GGX, who was of great encouragement to me is the
solving of this problem. He even suggested I record the noise. I did and sent
it to him to hear.
I finally decided to use the bruit force approach and used a 1000 UF
capacitor with one side grounded.
Starting at U9 the audio amp, shorting leads to ground through the
capacitor, I discovered the noise was coming in via the CW side tone path. I traced
the noise to the input to U 10B pin 5.
Under a high intensity light and a magnifying glass, all solder pads looked
clean and shiny.
Not knowing where else to go, I resoldered all the pins of U10 plus C36. I
suspect C36 may have been my problem but all that noise has now gone away.
Don Webb...KA7L
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