this is a follow video to this one in this series:
https://youtu.be/YCJpS0kCbQ0the PC's native MOBO sound card was set to 192Khz to enable direct 88Khz CW TRANSMIT from the AD5DZ CW KEYBOARD sending a text file
the LF RF 88Khz output of the PC's sound card goes to the input of the LOXJIE A10 Amplifier, the output of the LOXJIE A10 Amplifier goes to the input of a 4/1 ferrite impedance transformer, the output of the ferrite transformer is - series cap tuned - to peak resonance at LF RF OUTPUT 88Khz for maximum LF RF current through the compact 21 foot long Delta Loop Transmit Antenna(a VERY inefficient length for 88Khz LF BAND...yet still strong enough to produce a very strong LF RF EMF RX signal in the RX ANTENNA(s) despite the very low EIRP output of the short delta loop wire antenna)
RX antenna(s) - TUNED TWIN COIL FERRITE ROD connected directly to the recording laptop's STEREO MIC JACK INPUT...and a 2nd passive tuned ferrite rods/airdux coil RX antenna is in close proximity to the 1st TX antenna, significantly increasing the RX pickup LF RF signal from the transmitter into the LAPTOP's mic jack input circuit
LSB DEMOD SDR APPs by AD5DZ
NOTE: this LOXJIE A10 AUDIO AMP comes with its own power supply - 19 volts at 6 amps -
one of the higher powered - voltage power supplies - with enough current/voltage, to reach the advertised power output ratings...of the CLASS-D AUDIO AMPS i have tried from AMAZON, i had to send 2 of them back - total fail...so... so far...i am happy with this LOXJIE A10...for being able to operate in the LF BAND up to the sound card limit of 96 Khz...and at a high power output into the ANTENNA...
you have to be careful with the LOAD, so, 2, 2 ohm resistors are being used to provide "enough" load to the amp so it does not shut down from its protective circuit...AND...you have to select your transmit antenna TUNING caps carefully...OR...they will get HOT ! and their voltage rating must be high enough at least 100 volts or more...so you don;t blow them out from the high current, high Q tuned delta loop antenna...even with that BIG BROWN CAP(shown in video) - .25 uF, it is still getting WARM...so i should replace it with a better CAP brand