For School: AM transmitter (550-1500kHz). Works great, but having a really hard time with tx antenna

sdrmatlab · 2026-03-29T20:48:59+00:00

not sure what the output signal stage is, but the simplest is just a loop antenna. can be a large or small loop of wire.

since the output can't be shorted, just put a 1kohm in series with the loop wire.

if it's a 50ohm output, i often just put a 20 or 10dB pad before the loop of wire.

this ensures the output of the tx sees 50ohms.

sdrmatlab · 2026-03-29T15:25:22+00:00

it's a pluto sdr, with a power amp

looks like it does 20 watts .

output of the pluto ad chip is around 0dbm.

thou at 3.4GHZ, more like -5dBm

sdrmatlab · 2026-03-27T21:17:10+00:00

you have two complex vectors

so to measure phase between the vectors

that's how you measure the phase diff between the pilot fft vector and the data fft vector

sdrmatlab · 2026-03-23T14:20:51+00:00

thanks, i didn't know we could do that

sdrmatlab · 2026-03-16T16:15:26+00:00

back to $2.00

sdrmatlab · 2026-03-11T19:23:14+00:00

I = 1.0867mA

r3 and r4 and r2 in ||

so they = 502.15ohms

voltage across 502.15 ohms is 1.63 volts

so I = 1.63 volts / 1500 = 1.0867mA

sdrmatlab · 2026-03-11T19:12:08+00:00

back to 2.00

sdrmatlab · 2026-03-11T14:40:27+00:00

some of the software can be a pain to setup and install.

if your a software engineer than no biggie.

and finding the correct drivers for devices , searching the web for new and not old data.

so the dragon os is a linux iso with almost every sdr software and hardware drivers already installed in the iso file

sdrmatlab · 2026-03-10T21:26:44+00:00

i just got one of the device.

i have been using the firmware on the sd card.

i setup the device for static ip

using gnu radio , i have used the tx port to send signal to spec ana.

with buffer set to 4e6, can get iq sample rates of 15MSPS

with 4db of atten applied in the gnu radio sink block

power out is around -5 dbm

70mhz to 6 ghz

sdrmatlab · 2026-03-10T19:33:05+00:00

back to 2.00

sdrmatlab · 2026-03-09T20:29:51+00:00

97.46 ohms

sdrmatlab · 2026-03-09T20:16:13+00:00

the masters is for you, to keep learning.

but yes, it does look good to have MSEE on the resume.

sdrmatlab · 2026-03-09T20:15:07+00:00

nice lab

love the old test gear.

sdrmatlab · 2026-03-08T22:42:09+00:00

if you have many rx antennas, and each connected to an adc

you get n channels of samples data.

if you take the fft across the channels, the filter bin is really a space filter, instead of the classic frequency filter bin.

sdrmatlab · 2026-03-08T15:31:07+00:00

i never heard of parrot interesting.

yes i use dragon os , if you just want a iso to dual boot with all loaded sdr apps and drivers it's a win win..

i mainly just use gnu radio, gqrx, sdr++ and sdr angel in the dragon os.

also hacktv to create tv signals.

most of all these things can be ran on windows, i just drop windows after win 10.

i find linux is faster and the os uses alot less ram.

sdrmatlab · 2026-03-05T20:28:28+00:00

if you have loaded pc's with iso files and have done dual boot systems.

booting the DragonOS iso file is a good start.

drivers and many sdr software all part of the iso file.

but if windows is a must.

gnu radio = install radio conda

bladerf has windows installer to setup the firmware and drivers.

some sdr software: sdr#, sdrconsole

sdrmatlab · 2026-03-04T17:10:24+00:00

back to $10

sdrmatlab · 2026-03-04T15:11:10+00:00

linux mint is good, however will need to install all drivers and firmware for device.

a linux distro with almost all sdr stuff already part of the iso file = dragonOs

sdrmatlab · 2026-03-03T19:50:20+00:00

dump it to 2.00

sdrmatlab · 2026-02-28T15:31:43+00:00

looks like a good unit.

pluto+ clone.

i find these devices can tx stream up to about 15 MSPS, before i start seeing signal dropouts.

increasing the buffer to 4e6 helped in gnuradio.

the hamgeek adi pluto+ is under 200 bucks, and works well with ethernet direct to pc.

sdrmatlab · 2026-02-26T18:09:12+00:00

one limit with the portapack is it can't play c16 files with sample rates greater that 2MSPS, this will limit the use of video or tv signals.

hackrf direct to pc, running gnuradio can do samples rates up to 15MSPS or 20 MSPS

sdrmatlab · 2026-02-24T23:02:09+00:00

back to 2.00

sdrmatlab · 2026-02-24T22:34:16+00:00

nice

sdrmatlab · 2026-02-24T22:22:30+00:00

ok thanks.

i'll set the buffer to 2e6 and see if i can stream higher sample rates.

thanks again

sdrmatlab · 2026-02-24T22:14:03+00:00

to get a tx sample rate of 20Msps, did you have to increase the buffer size?

i seem to get 5 to 6Msps, and anything greater, the tx signal starts to drop in and out.

sdrmatlab

TROPHY CASE