MLA-30 power-side attenuator

[@SezerAvar]

Thanks for your sharing 👍 📻

[@Ken.s_BCL-LogVideo]

Thank you for watching.73s!

[@catalinalb1722]

this potentiometer increase / decrease the bias-T ⚡ voltage supplied to the antenna?

[@Ken.s_BCL-LogVideo]

Hello, Mr. Catalin Alb. Thank you for watching. This potentiometer attenuates the antenna output. The supply voltage to the antenna remains at 12V and does not change.73s Tengu

[@MrBrian8749]

I missed this video Mr. Tengu... I never opened the power box, but I can see it was already adjusted for maximum performance. 73s Brian

[@Ken.s_BCL-LogVideo]

Hello, my friend. Thanks for watching. Yes, the potentiometer on the power supply was set to MAX. Looking at this circuit diagram, the antenna-side potentiometer applies negative feedback. I think it's expanding the band. bit.ly/2Vb3Ev5 By the way, I am also interested in this bandpass filter. ebay.to/37NtnMZ 73s (^^)/📻

[@Ken.s_BCL-LogVideo]

What surprised me when I saw this blog is that the circuit diagram shows how to drive the bias tee at 12v. 73s Tengu

[@ivvitan]

Great feature in this cheap loop antenna!

[@Ken.s_BCL-LogVideo]

Thank you very much.73s Tengu🌈

[@logonazo]

Hi!! i just bought one of this,...and i was thinking if i've to attenuate the Mla-30 to connect to my xhdata d-808 portable multiband radio...or it doesn´t matter,...thank you for your videos!! Cheers from Barcelona!!.

[@Ken.s_BCL-LogVideo]

Nice to meet you, Mr. Álvaro. Thank you for watching. The D -808 has good sensitivity, but when connected to an external antenna, it may cause intermodulation due to the influence of the local broadcasting station. I hope you have a good DX.73s Tengu🌈📻🌸

[@logonazo]

@@Ken.s_BCL-LogVideo Thank you for your quick answer! But are you talking about FM, right? i want the antenna for SW & Air band...thanks in advance and take care in those dark days!!!

[@dxonda7089]

Bien visto Tengu. Gracias por el aporte. ¿Esto significa que se podría interactuar con los dos atenuadores? 73.

[@Ken.s_BCL-LogVideo]

Hello, Mr. Onda. Thank you for your comment. It is just a guess as there is no circuit diagram or instruction manual. First, about the power side attenuator. This is used to reduce the output of the signal. For example, when connecting to a radio without an antenna input terminal. It is usually connected to a rod antenna. This can cause the signal to be too strong, saturating the radio and causing cross modulation. In that case, I think it will be improved if you reduce the output signal. Next, regarding the potentiometer on the antenna side, I think it adjusts the Negative FeedBack amount of the antenna pri-amplifier circuit during amplification. Increasing the Negative FeedBack decreases the amplification factor, but increases the amplification band and reduces distortion. Conversely, reducing the amount of Negative FeedBack, Increase the rate of amplification reduces and the bandwidth and creates distortion. As a result, strongsignal（local-MW,ham and CRI, etc), cross modulation occurs in the antenna circuit. In particular, I believe that the optimization on the antenna side differs depending on the receiving location. 73sTengu 📻 [Blog used as a reference] www2.ayu.ne.jp/user/inoue/MagLoop/MagLoop.htm www2.ayu.ne.jp/user/inoue/MagLoop/QST1.GIF www2.ayu.ne.jp/user/inoue/MagLoop/QST2.GIF

[@dxonda7089]

​@@Ken.s_BCL-LogVideo OK. Deduzco que viene optimizada de fábrica o dicho de otra manera este sería su punto de equilibrio aunque se pueda retocar mínimamente ¿Es así?

[@Ken.s_BCL-LogVideo]

@@dxonda7089 Yes, as you said, standard points should be optimized for this standard element. For example, if change an element to a larger diameter, it is good to be able to adjust the constant.73s!

[@dxonda7089]

@@Ken.s_BCL-LogVideo OK, gracias. 73.

[@sa6kod154]

The less. The better?

[@sa6kod154]

Edit: just saw your description. Now I understand

[@Ken.s_BCL-LogVideo]

@@sa6kod154 The default is MAX. If you connect another sensitive preselector, you may need to turn it down. probably.73s!🎄