[TenTec] Orion freezes due to RFI??
Henry Gardiner
hgard1 at airmail.net
Mon Dec 15 19:47:11 EST 2003
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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