20dB Coupler with 3rd port disconnected
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- Posts: 26
- Joined: Thu Aug 09, 2018 12:40 pm
20dB Coupler with 3rd port disconnected
Stupid question time. I have a 20dB 200W 3 port coupler. If I unplug the power meter from the coupler sampling port will it affect the matching of the straight thru ports ? I am thinking it will not but just want to make sure. Just wondering if I can leave a coupler in line when used in conjunction with a high power PA at 2.4GHz.
73s
Darren G4VTQ
Darren G4VTQ
Re: 20dB Coupler with 3rd port disconnected
I would suggest that any loading or mismatch would be down at -20 dB to an open port and -20 dB back so around 40 dB down, so not really having much of an effect, but, If you have any concerns about it then just connect a small dummy load to the port and give it 50 Ohms.
Adrian
Adrian
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- Posts: 26
- Joined: Thu Aug 09, 2018 12:40 pm
Re: 20dB Coupler with 3rd port disconnected
Thanks for the advice Adrian. It puts my mind at rest. Didnt want to destroy the amp.
73s Darren G4VTQ
73s Darren G4VTQ
73s
Darren G4VTQ
Darren G4VTQ
Re: 20dB Coupler with 3rd port disconnected
Hello Darren, it is my assumption anyway, it will probably be slightly worse then -40 dB down as that should be the case when terminated with 50 OHms so when not terminated it will probably be higher.
I would find a 1 to 5 watt load and stick it on the 3rd port.
Adrian
I would find a 1 to 5 watt load and stick it on the 3rd port.
Adrian
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