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-----Original Message-----
From: Phil Clements <philk5pc@tyler.net>
To: amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
Date: Monday, July 05, 1999 5:14 AM
Subject: [AMPS] In Search Of: The Nearly Perfect T-R Switch
=20
=20
IMHO, the use of mechanical relays for T-R switching modern radios =
and amplifiers
is about 10 years behind the times. The PIN diode T-R switch =
introduced by Heath
for the SB-1000 amp, and later produced by Ameritron as the QSK-5 is =
using old
hardware and technology. Ameritron was challenged by an article in =
QST some years
back to use newly available, much more robust PIN diodes in their =
products. I followed
this up by calling Ameritron and asking if they had plans to =
modernize the QSK-5.
The guy I talked to at the time said Ameritron had no plans to make =
any upgrades in
the unit, which proved to be true, as there have been no changes to =
this date in the QSK-5.
Their only upgrade available is a fan to supposedly increase the =
power handling capability.
=20
In the mid '80's, an outfit called Design Electronics Ohio, out of =
Groveport emerged with
a product called the QSK-1500.( Does anyone know what happened to =
these folks?)
In 1985, a fellow by the name of Phil Pesavento developed the =
QSK-3000, using the
new Macom 4P902-985 PIN diodes. These diodes were apparently very =
robust, as the
technical manual describes that they are installed on the board with =
wrenches! (Has anyone
ever heard of Macom, especially where to purchase these diodes?)
=20
=20
The Macom (MA Comm ?) you speek of is still around. Used to be known =
as Microwave Associates.=20
=20
=20
Can anyone furnish any knowledge of the company and/or experiences =
with the QSK-1500 or
QSK-3000?
=20
(((73)))
Phil, K5PC
=20
=20
73 Jim W7RY
=20
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<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: =
5px">
<DIV><FONT face=3DArial size=3D2><B>-----Original =
Message-----</B><BR><B>From:=20
</B>Phil Clements <<A=20
=
href=3D"mailto:philk5pc@tyler.net";>philk5pc@tyler.net</A>><BR><B>To: =
</B><A=20
href=3D"mailto:amps@contesting.com";>amps@contesting.com</A> <<A=20
=
href=3D"mailto:amps@contesting.com";>amps@contesting.com</A>><BR><B>Dat=
e:=20
</B>Monday, July 05, 1999 5:14 AM<BR><B>Subject: </B>[AMPS] In =
Search Of:=20
The Nearly Perfect T-R Switch<BR><BR></DIV></FONT>
<DIV><FONT color=3D#000000 size=3D2>IMHO, the use of mechanical =
relays for T-R=20
switching modern radios and amplifiers</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>is about 10 years behind the =
times. The PIN=20
diode T-R switch introduced by Heath</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>for the SB-1000 amp, and later =
produced by=20
Ameritron as the QSK-5 is using old</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>hardware and technology. =
Ameritron was=20
challenged by an article in QST some years</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>back to use newly available, =
much more=20
robust PIN diodes in their products. I followed</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>this up by calling Ameritron and =
asking if=20
they had plans to modernize the QSK-5.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>The guy I talked to at the time =
said=20
Ameritron had no plans to make any upgrades in</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>the unit, which proved to be =
true, as there=20
have been no changes to this date in the QSK-5.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>Their only upgrade available is =
a fan to=20
supposedly increase the power handling capability.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>In the mid '80's, an outfit =
called Design=20
Electronics Ohio, out of Groveport emerged with</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>a product called the QSK-1500.( =
Does anyone=20
know what happened to these folks?)</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>In 1985, a fellow by the name of =
Phil=20
Pesavento developed the QSK-3000, using the</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>new Macom 4P902-985 PIN diodes. =
These diodes=20
were apparently very robust, as the</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>technical manual describes that =
they are=20
installed on the board with wrenches! (Has anyone</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>ever heard of Macom, especially =
where to=20
purchase these diodes?)</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT size=3D4>The Macom (MA Comm ?) you speek of is still =
around. Used=20
to be known as Microwave Associates. </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Can anyone furnish any knowledge =
of the=20
company and/or experiences with the QSK-1500 or</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>QSK-3000?</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>(((73)))</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>Phil, K5PC</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2> </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D4>73 Jim W7RY</FONT></DIV>
<DIV><FONT size=3D4></FONT> </DIV>
<DIV><FONT size=3D4></FONT> </DIV></BLOCKQUOTE></BODY></HTML>
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