[TenTec] Orion freezes due to RFI??

[Rick Westerman]

Henry,

Here is my first pass.

Check it and let me know if I need to change anything.

It was created in PowerPoint and you may have the file in that
format or most any other if you wish.

73
Rick

-----Original Message-----
From: tentec-bounces at contesting.com
[mailto:tentec-bounces at contesting.com]On Behalf Of Henry Gardiner
Sent: Tuesday, December 16, 2003 2:47 AM
To: Rick at dj0ip.de; tentec at contesting.com
Subject: Re: [TenTec] Orion freezes due to RFI??

Rick,
     Here is what I used to bypass the speaker output jack on my
RX-350D
aka JUPITER rcvr.
    0.1 uF disc capacitors go to ground from each of the three
pins on the
jack that have traces going to them.  Also a three-winding
common-mode
blocking transformer.  I used three lengths of 22 ga magnet wire
twisted
together at a convenient rate.  This was wound through the
FT50-72 core 5
times. This was interposed in the circuit between the jack pins
and the
nearby pcb connectors using a Dremel tool with fiberglass cutting
disk to
cut the three traces.  AAACK!!!  Use the same winding polarity in
each
case.  Ie, if the counterclockwise end of a winding goes to a
speaker jack
pin, so should the counterclockwise end of the other windings go
to their
respective speaker jack pins.
     Might try this first with just the three 0.1 uF disc caps
plus your
external clamp-on ferrite choke. That might eliminate the need
for the
transformer and the cut traces.  Or you may end up using the
transformer,
caps and clamp-on choke.
     Basic parameters: Each winding is about 100 ohms at 1 mHz.
The caps
are something like 1.5 ohms at 1 Mhz.  The toroid data is in the
ARRL
Handbook in the chapter "Component Data".
     This schematic expects a mono-spaced font like Courier or
Courier
new.  Might be easier to cut it and paste it into an editor and
change the
font there.
     Perhaps we should let this get reviewed for a while before
one of us
invests the time in drawing the schematic more formally.

73,
Henry AC5LA




             J3
            +--++                                          J5
      To    |  ||2-+                              Rear Panel Spkr
Jack
    Speaker |  ||  |
            |  ||1-)--+        +---+-----------------o----------
            +--++  |  | Xformer|   |                     /|\ .
                   |  |  .___  |   |              +--o----|  .
                   |  +---UUU--+   |              |          .
++
                   |     .___      | +-------+----)--o--------\
||
                   +------UUU------)-+       |    |            \/
||
             J4    |     .___      |
+----)----+--o-------------++
            +--++  |  +---UUU------)----+    |
   To       |  ||2-+  |            |    |    |
   HdPhones |  ||     |            |    |    |
   Jack     |  ||1----+           ---  ---  ---
            +--++                 ---  ---  --- 0.1 uF 25V
                                   |    |    |    x 3  disc
ceramic
                                   |    |    |   Connect caps to
three
terminals on speaker
                                   |    |    |   jack with traces
leading
to them from pcb
                                   |    |    |   connectors.
                                  ===  ===  ===
                                  GND  GND  GND
                                       GND:
                                       Trace Leading
                                       To Nearby
                                       Mounting Post

created by Andy´s ASCII-Circuit v1.24.140803 Beta
www.tech-chat.de


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