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Out of curiosity, I removed the plug on the IF board that
one of the guys mentioned helped the sidetone "pop".
On my particular Six, it made no difference, other than
it defeated it's purpose, which is to make the sidetone
independent of the audio gain control. After some paying with it,
I put it back as normal.
There also have been suggestions of removing the relay for
keying. I had modified mine quite a while ago, but I approached
it somewhat differently.
1) Remove the control board
2) Unsolder and remove both the relay and the driver transistor.
3) Replace the transistor with a high voltage Silicon NPN transistor,
(The type is unimportant, as long as it will handle a couple =
hundred
volts and preferably a good amount of current, such as 1/2 amp)
4) In the holes vacated by the relay coil, and the output contacts,
install a CEMF diode. Any silicon rectifier diode is fine. I =
used a
1000 PIV/1 amp diode.
5) Reinstall the control board.
The advantage is that no mods are made to the board and can be
returned to factory fresh with no evidence that it was ever modified
should that become an issue.
The results are as expected, and truly makes a silent operation. My
amp is a 4CX1500B and my vacuum relays are well inside the amp guts,
and when I hit the key, the only sound heard is the sidetone. Sometimes
I have to look at the wattmeter to make sure I'm really transmitting!
de KL7HF
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<DIV><FONT color=3D#000000 size=3D2>Out of curiosity, I removed the plug =
on the IF=20
board that</FONT></DIV>
<DIV><FONT size=3D2>one of the guys mentioned helped the sidetone=20
"pop".</FONT></DIV>
<DIV><FONT size=3D2>On my particular Six, it made no difference, other=20
than</FONT></DIV>
<DIV><FONT size=3D2>it defeated it's purpose, which is to make the=20
sidetone</FONT></DIV>
<DIV><FONT size=3D2>independent of the audio gain control. After some =
paying with=20
it,</FONT></DIV>
<DIV><FONT size=3D2>I put it back as normal.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>There also have been suggestions of removing the =
relay=20
for</FONT></DIV>
<DIV><FONT size=3D2>keying. I had modified mine quite a while ago, but I =
approached</FONT></DIV>
<DIV><FONT size=3D2>it somewhat differently.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>1) Remove the control =
board</FONT></DIV>
<DIV><FONT size=3D2>2) Unsolder and remove both the =
relay and=20
the driver transistor.</FONT></DIV>
<DIV><FONT size=3D2>3) Replace the transistor with a =
high=20
voltage Silicon NPN transistor,</FONT></DIV>
<DIV><FONT size=3D2> (The type =
is=20
unimportant, as long as it will handle a couple hundred</FONT></DIV>
<DIV><FONT size=3D2> volts and =
preferably a good amount of current, such as 1/2 amp)</FONT></DIV>
<DIV><FONT size=3D2>4) In the holes =
vacated by the=20
relay coil, and the output contacts,</FONT></DIV>
<DIV><FONT =
size=3D2> install=20
a CEMF diode. Any silicon rectifier diode is fine. I used a</FONT></DIV>
<DIV><FONT size=3D2> 1000 =
PIV/1 amp=20
diode.</FONT></DIV>
<DIV><FONT size=3D2>5) Reinstall the control =
board.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>The advantage is that no mods are made to the board =
and can=20
be</FONT></DIV>
<DIV><FONT size=3D2>returned to factory fresh with no evidence that it =
was ever=20
modified</FONT></DIV>
<DIV><FONT size=3D2>should that become an issue.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>The results are as expected, and truly makes a =
silent=20
operation. My</FONT></DIV>
<DIV><FONT size=3D2>amp is a 4CX1500B and my vacuum relays are well =
inside the amp=20
guts,</FONT></DIV>
<DIV><FONT size=3D2>and when I hit the key, the only sound heard is the =
sidetone.=20
Sometimes</FONT></DIV>
<DIV><FONT size=3D2>I have to look at the wattmeter to make sure I'm =
really=20
transmitting!</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>de KL7HF</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV></BODY></HTML>
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