The AM Forum

Having a little fun on my SDR Receiver. This is Radio Marti , all I can say is Wow. I have never seen such intense audio density like this. They are brick walled at 5 khz of audio, excellent curve with good high frequency response and very clean RF bandwidth wise. WBCQ, WRMI, WWCR all have great audio density and bandwidth control, but nothing like this. They must be running asymmetrical audio and screaming all the audio processor's to the limit. They are loud as you would expect, but surprisingly still sound clean. Maybe hammy AM'ers should take a page from their book ??


Note: Radio Marti is a state run radio international broadcaster & financed by our Glorious government with studios based in Miami. Providing the nice people of communist Cuba news & info. Shortwave transmitters operating out of Delano, California & Greenville, North Carolina.

20 over and dense in Tumtum,WA  Gud Stuff

There is nothing run out of Delano.


Radio Marti is run out of Miami, with the transmitter plant in Marathon Key, Florida.  If you want to find it, look for Blimp road.  The antenna wire is a trailing wire from a blimp!  At 100kw ERP daily.

Delano has been dark for decades.

--Shane
WP2ASS / ex KD6VXI

Marathon Key is the mediumwave site, on 1180. Greenville, NC, or more precisely Greenville site B, there was a twin to it referred to as site A which is now decommissioned, is the HF transmit site. I don't get a nice clean signal here most of the time because Cuba loves their jammers.

Yes.

I've been to Delano multiple times.  Had the county sheriff run me off once.  The farmers around the facilitybate pretty cool, they are used to radio nerds coming to look at it.

Always wanted to sneak on and connect to the curtain.  Never had the cajones to pull it off.

All rusting away silently now.


I have ZERO issues getting Marti on MW or SW where I'm at now. 

--Shane
WP2ASS / ex KD6VXI

Back when I was working for Cheap Channel we had Optimod AM nine thousand series digital processors. It was a company policy to run the AM stations at 5 KHZ and for sports and talk they sounded great. We did annual NRSC compliance checks to confirm that we were under 10 KHZ total but the DSP in the Optimod was way on top of that.  The weird thing is that on a SDR you would see the big pronounced skirts with bandwidth limiting but not as much on a spectrum analyzer? Still cannot account for the difference in what you see on a spectrum analyzer and on an SDR but the analyzer was what we used for FCC compliance.

SW broadcasters typically do not run asymmetric modulation as it increases the effects of selective fading (QSB) distortion as well as increased distortion in diode detectors. There's also no measurable increase in loudness from running >+100% but it looks cool on Watt meters.

I don't suppose they would discuss their audio processing. It sure is an example to follow though.