Tobi A Posted September 1, 2022 Report Share Posted September 1, 2022 I'm thinking of adding some inline RF attenuators to my links/hops transmitters in my bag setup, to help my recievers out with spray etc. I'm using smqv and the min power output is 50mW, I think half that or even less would be enough from my bag to camera which is usually close. Has anyone one done be this? I recall a discussion somewhere but can't find it now. How much attenuation would I need? 5db, 10db? If anyone knows the formula that would be amazing! Quote Link to comment Share on other sites More sharing options...
jason porter Posted September 2, 2022 Report Share Posted September 2, 2022 Rule #1 is have at least 50mhz of separation between hops and bag Rx. Rule #2 get hop tx away from Rx. Rule #3 use Rx with a "tight" front end filter (411!) I think a 3db attenuator would effectively cut the power in half, but now you have an awkward tx antenna situation that could easily result in a broken SMA connector. Quote Link to comment Share on other sites More sharing options...
Tobi A Posted September 2, 2022 Author Report Share Posted September 2, 2022 Yep following rules 1-3 which is working pretty well, just trying to get that extra 5%! Good point about the potential broken SMA. Quote Link to comment Share on other sites More sharing options...
codyman Posted September 2, 2022 Report Share Posted September 2, 2022 I think using an app like FreqFinder to make sure you don't have any inter-modulation would help more than trying to reduce the power. Spacing bag hops as far away (and make sure they don't conflict frequency wise) goes a long way! Quote Link to comment Share on other sites More sharing options...
Tobi A Posted September 2, 2022 Author Report Share Posted September 2, 2022 Absolutely, I've been using the txAdvance app which is excellent Quote Link to comment Share on other sites More sharing options...
karlw Posted September 2, 2022 Report Share Posted September 2, 2022 SMA type 3dB attenuators should work very well in that application. If you are getting plenty of range with say 25 mW coming out of your hop transmitter/s, then this is a good option. They will make the antenna/base connector about 3/4" longer, as Jason mentioned. Quote Link to comment Share on other sites More sharing options...
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