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(C)
The use, copy and modification of all info on this site is only permitted for non-commercial
purposes, and
thereby explicitly mentioning my radio amateur call sign "pa0nhc" as
the original writer / designer / photographer / publisher.
DIY masks for directional couplers
with DC and RF output.
Directional couplers with
RF-output.
For measuring return losses using very low power.
Shown are PCB's for different connectors and casings.
BNC receptacles are of screw-nut-type
with PTFE (Teflon (R)) dielectric.
Casings used are TEKO type 371 or
372.
N receptacles
are of flat flange-type with PTFE dielectric.
PTFE insulation enables soldering
of the outside of the bus to the PCB and/or steel enclosure, due to the high
melting temperature of the material.
The flanges of N busses are
soldered onto the copper bottom lane of the PCB.
Solder the the mass-connections of the PCB to the nuts of the BNC
receptacles,
not to the box itself.
All PCB tracks are soldered directly
under the center-pins of all BNC's.
Before
installing the BNC busses, lay the PCB into the enclosure FIRST.
The "50 ohms" terminating resistors comprises each of 3 SMD
resistors 150 ohms in parallel.
IMPORTANT:
The back plane is full copper.
The little holes must be filled with copper
rivets or pieces of thick wire, and then soldered on both sides of the PCB
These are interconnections between mass planes on both sides of the PCB.
Reverse the diodes if negative DC
output is wanted.
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There are NO Gerber
files for the following masks.
They were simply drawn using Paint Shop Pro in 1999.
Open the PDF
versions in Adobe Reader,
and print them in size "100%".
RF currenst
should flow through the back plane of the PCB,
NOT through the metal screening of the
box.
Leave the PCB free from the box.
The PCB mass planes must ONLY be
soldered to the nuts or thread of the connectors.
The mass connections to be soldered, are marked with a "ground" sign.
The signal tracks (RF and DC) are soldered directly under the center-pins of connectors. |
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PCB 78mmx44mm, BNC
receptacles on sides.
Download this mask as PDF.
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PCB 48x44mm, with BNC
receptacles on two sides,
and two N receptacles screwed to the outside of the back.
Per N receptacle, use two short screws with their heads inside.
Further use two longer screws with the heads outside.
Then place inside on each some nuts as spacer.
Fix the PCB to the long screws with a nut and a teeth washer.
Then install the BNC's and solder the PCB to all receptacles.
Download this mask as PDF.
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Universal PCB 48x44mm,
BNC receptacles on all sides,
or N-receptacles on the on the back.
Download this mask as PDF.
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Directional couplers with
DC-output.
For use in SWR / power meters.
Read also the instructions
above about mass connection.
The components for DC output :
The RF-filters in the DC-outputs are SMD-components :
- At the diode (BAT85) : 100pF to mass,
- From diode to output 150 ohms ,
- Output connections "X" are bridged with 10nF.
X= The DC output connection to
- BNC receptacles or
- Feed-through-Cs and external screened wires.
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Parts locations
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Parts locations for DCout
couplers.
Left to rigth : BNCpin, filterR (= 150 Ohms or higher),
filterC=100p
The "50 ohms" terminating resistors comprises each of 3 SMD
resistors 150 ohms,
soldered on top of each other (in parallel).
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PCB 48x44mm, BNC
receptacles on sides.
Download this mask as PDF.
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PCB 48x44mm, with BNC
receptacles on two sides for DC output,
and two N receptacles for RF screwed to the outside of the back.
Per N receptacle, use two short screws with their heads inside.
Further use two longer screws with heads outside,
and place inside each some nuts as spacer.
Fix the PCB to the long screws with a nut and a teeth washer
Then install the BNC's and solder the PCB to all receptacles.
Download this mask as PDF.
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Universal PCB 48x44mm,
BNC receptacles on all sides, or N- receptacles on the back.
Download this mask as PDF.
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