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Improving the MLA-30

Posted: Wed Apr 05, 2023 7:21 pm
by Andrew (grayhat)
Here are some suggestions, in case you decided to buy it, that is :)

First step, improve the loop; either use some copper pipe or alumium strip to make a wider and BIGGER loop (easy)

Second step; match the impedance, the preamp has an impedance ranging from 1.5K down to 450Ohm, now ler's find a balance, break the loop at top and use a 975Ohm resistor to connect the two halves

Third step: the preamp to bias tee coax sucks badly, add a BNC connector to the preamp box and use a run of decent coax (RG6 will do) to feed the loop

Fourth step: the BIAS Tee unit was designed by a drunk folk, replace it asap

Re: Improving the MLA-30

Posted: Sun Apr 09, 2023 10:23 am
by Egil - LA2PJ
Never used a MLA-30 myself, but today I more or less stumbled over this discussion where they also have published schematics for both loop amplifier and bias-T:

https://www.eevblog.com/forum/rf-microw ... p-antenna/


Good luck!

Re: Improving the MLA-30

Posted: Mon Apr 10, 2023 6:19 am
by Andrew (grayhat)
Yep Egil, know that, all in all I wrote that post :D