Messages

1

North American Shortwave Pirate / Liquid Radio 6925 AM 0103 UTC 16 SEP 2025

« on: Today at 01:05 »

I noticed it's reasonably strong and good copy on the Lodi Farm SDR in the Finger Lakes, New York State, but I'm listening on an SDR in Texas.

0104 - No ID yet but given the signal strength in Texas and the EDM, it's a safe bet.

0110 - Liquid Radio ID, next track
0131 - Inner City, "Big Fun"
0138 - S'Express, "Theme from S'Express"
0149 - ID, Friends of Matthew, "Out There"
0202 - ID, Transform, "Transformation"
0208 - Cortina, "Music is Moving"
0218 - The Prodigy, Charly". The band is finally going long and station is fading out in TX. Time to change SDR.
0223 - EGMA, "Let the Bass Kick". Ended up on the WA7CCA SDR in Concho, Arizona.
0231 - Modigliani, "Lost In Your Eyes"
0246 - It's time for me to go. The reception is also good on the SW Missouri & the Chetek, Wisconsin Kiwi SDRs at the moment.   Good night.

2

North American Shortwave Pirate / Re: Liquid Radio 6925 AM 0104 UTC 13 SEP 2025

« on: September 13, 2025, 0158 UTC »

Fair signal on an SDR in Texas. Very noisy tonight. Shazam is having trouble with the songs. The one song it ID'ed turned out to be incorrect.

0157 - Liquid Radio ID, next tune.
0211 - "That looks like asbestos..." with ID. Next tune. Moved to the WA7CCA SDR in eastern Arizona.
0238 - Kraftwerk, "Robots"

0240 - It is time for me to go. Good night.

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North American Shortwave Pirate / Re: Big Mac Radio 6915 USB 0006 UTC 13 SEP 2025

« on: September 13, 2025, 0036 UTC »

0035 - Close down announcement with "Keep 43 meters weird, my friend."

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North American Shortwave Pirate / Re: ION Radio 6890 AM 2353 UTC 12 SEP 2025

« on: September 12, 2025, 2357 UTC »

2359 - Ethereal music. SINPO 33333 on an SDR in New England.
0001 - "The chair is against the wall." (a la coded information for a spy) by YL with UK accent several times with musical bits.
0003 - Recording of Ronald Reagan repeating a Soviet joke about whether they had actually achieved Communism.
0013 - The Beach Boys, "In My Room"
0014 - ION Radio ID by UK-accented YL.

I have it as a carrier with two sidebands, not just an upper sideband. Are we looking at the same thing?

Yes, sorry, it IS AM.

No worries, man.

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North American Shortwave Pirate / Re: UNID 6890 AM 2250 UTC 12 SEP 2025

« on: September 12, 2025, 2259 UTC »

About S7-S9, SINPO 44333 on an SDR in New England. Very under-modulated.

2258 - TX Off.

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North American Shortwave Pirate / Re: Mix Radio International 6850 USB 0032 UTC 12 SEP 2025

« on: September 12, 2025, 0257 UTC »

Not that there was much doubt but ID comes from the words written in the waterfall on the high end of the sideband.

7

North American Shortwave Pirate / Liquid Radio 6955 AM 0116 UTC 12 SEP 2025

« on: September 12, 2025, 0119 UTC »

Just tuned in. Very strong on a Texas SDR. SINPO 55555. Presumed to be LR based upon signal strength and music.

0118 - The Crystal Method, "Busy Child"
0126 - Liquid Radio ID, into Patrice Rushen, "Forget Me Nots."
0131 - ID, next song.
0136 - ID, next is Laura Branigan, "Self Control"
0143 - Culture Club, "Move Away." Fading is increasing as the FoF2 changes and the band starts to "go long."
0152 - ID then ABC, "Be Near Me"
0156 - Animotion, "Obsession"
0201 - The Power Station, "Get It On (Bang A Gong)"
0208 - Talk Talk, "Life's What You Make It." Noise is increasing. SINPO 55344.
0211 - Naked Eyes, "Promises, Promises"
0214 - Rapid drop in quality all the sudden. SINPO 33322. I'm going to change SDR.
0237 - Metropolis, "Time of War"
0252 - TX Off

8

Latin American Pirate / Re: UNID 6935 AM 2341 UTC 4 SEP 2025

« on: September 05, 2025, 0101 UTC »

This was definitely AD149.  I tuned in to an Argentine SDR, and a clear ID in English was given just before signoff.

and there you have it.

Moderator - Please move this to the Latin America section. Thank you.

9

Latin American Pirate / Re: UNID 6935 AM 2341 UTC 4 SEP 2025

« on: September 05, 2025, 0049 UTC »

I heard some of this on an SDR in New England. I presume it to be AD149 from Argentina given the signal strength and music.

0009 UTC: "Por Qué" by Cetu Javu. Thinking this may indeed by AD149.

Seconded!

10

North American Shortwave Pirate / Re: Liquid Radio 6925 AM 0033 UTC 5 SEP 2025

« on: September 05, 2025, 0043 UTC »

0040 - Very strong on a Texas SDR. Given that and the music, I presume that this is Liquid Radio.
0043 - Liquid Radio ID.
0053 - Liquid Radio ID 4x. Man with an Australian accent giving a commercial message (with plenty of innuendo) about "Dickin Cider." 
0100 - Sandra Collins, "Red."
0106 - ID. (Paraphrasing) "Boy, that hole has a bunch of mileage on it. That hole has made a bunch of people happy over the years." Into Nitzer Ebb, "Let Your Body Learn."
0123 - A Split-Second, "The Colosseum Crash."
0207 - The Sisters of Mercy, "Dominion/Mother Russia."
0241 - Lords of Acid,"I Sit On Acid '95."
0250 - TX Off.

11

The RF Workbench / Re: U-LULU (Updated LULU) for 48 meters, 20 Watt Class-E AM Transmitter

« on: September 03, 2025, 0227 UTC »

Yes I know there are also good class-D and bad AB amps. I just happened to have very good class-AB modules laying around, good for up to 150Watts and 20Amps of current. These can easily drive the RF output up to 100% modulation without any issues.

Fair enough.

Im from Finland btw

After I wrote that I remembered that Finland now allows licensed "hobby broadcasting" so that makes sense.

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North American Shortwave Pirate / Re: Liquid Radio 6925 AM 0104 UTC 3 SEPT 2025

« on: September 03, 2025, 0204 UTC »

I have been listening on and off since transmitter on around 0100 (I think). Signal is a bit better in some parts of North America than usual. I'm guessing it is because of the current geomagnetic conditions (K=6, etc.) turning things on its head. The band conditions are volatile and I have been moving SDRs a lot as it doesn't take long for the signal to fade out.

SINPO 35343 to 35223 on SDRs in the south of the US at peak.

It appears to be 1980s night tonight.

0203 - Honeymoon Suite, "Feel It Again."
0206 - Huey Lewis & The News, "I Want A New Drug."
0215 - Van Halen (in the Sammy Hagar era), "Dreams."
0233 - Peter Gabriel, "Shock The Monkey."
0236 - Oingo Boingo,"Dead Man's Party."
0241 - TX off.

13

The RF Workbench / Re: Simplest PWM

« on: August 30, 2025, 2020 UTC »

You are using, of course, a classical push-pull Voltage-mode Class-D source. Here's a simulation model for something similar from a few years ago.

I use 13.5 V high voltage here because at the time I was trying to avoid the use of a separate HV inverter, hence the load represented as a 0.75 Ohm resistor. I used a TI UCC5350 dual gate driver, simply because there was already a model and symbol for it in the schematic capture tool, I use and Nexperia PSMN019-100YL transistors but many N-channel FETs will work here. C46/R60, C47/R61 and C48/R62 are snubbers to get rid of the usual ringing.

I use a Bessel filter here because I want a smoother group delay (the rate of phase change with frequency) than your Chebychev filter, though I fully admit that probably no one is going to notice the difference between a Bessel, a Chebyshev or a Butterworth filter at HF/shortwave. The filter response is probably too restrictive like this as there is some rounding of the edges with 1 KHz pulses. (See below.) The snubbers probably don't help in this regard, as their corner frequency is pretty low.

I should get rid of C45 and rejigger this since I would not want that there in the real application. The intent is that the last two elements in the output filter (one C and one L) would physically be on the RF board, where the L would be the RF choke. The remainder of the elements would be on the separate PWM board.

My notes say that I had a lot of problems getting this going in simulation with a 1 KHz source. Not completely surprising to me. I think that I tweaked this later; I just can't find the revised circuit model right now.

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The RF Workbench / Re: U-LULU (Updated LULU) for 48 meters, 20 Watt Class-E AM Transmitter

« on: August 30, 2025, 1920 UTC »

Congratulations on the license and becoming "official". I assume this means you are in the Netherlands or perhaps Germany. Maybe I will hear you on the air via SDR.

Well at first I tested many Class-D modules. Some of them failed and some did not have very good response. Modulated RF output had some distortion (modulation triangle on my scope was rounded) at higher power levels etc oddities.
I have some Class-AB modules too so I tested them and all problems gone. Modulation is now very linear up to 100%.

OK. I understand. There are many low-quality Class-D amplifiers available out there. Keep in mind that this sort of transmitter requires that the module produce quite a bit of DC output (several Amps) in addition to the audio output on top of that, just to keep the transmitter on the air. Without it the final transistor (in your case the IRF530) will not have sufficient drain voltage. I have found that not all the available Class-D modules, especially the inexpensive ones, can do this well, as it it is a bit above and beyond what it is supposed to do for just routine audio amplification. I believe that this may be part of what you were seeing.

You mentioned RFI susceptibility earlier. I can't tell if that is (also) what you were experiencing just based upon what you wrote, but there are some very simple steps to reduce the likelihood of RFI (grounding, shielding, ferrite beads, increased physical separation, etc.).

I have had good results with Sure (Wondom) Amplifiers, which is why I recommended them in the original document. These are Class-D.

Discrete Class-AB is just more robust anyway

I'm sorry but that's simply not true. You can make a crappy, non-robust Class-A, Class-AB, Class-C, Class-(take your pick) amplifier just as you can make a good one. It all depends upon whether it is appropriate for the application, "fit for purpose", as they say in the UK.

Just because you had bad results with some cheap Class-D amps absolutely does not indict all Class-D amplifiers. That's like saying that because you got food poisoning from some incorrectly-prepared chicken that all chicken is poisonous. It just does not stand up to the evidence.

The same goes for RFI susceptibility. Susceptibility to RF is a very niche need and it's not surprising that the makers of the very cheap Class-D amplifiers, who are under pressure to reduce every fraction of a cent in "extra" cost, did not worry about trying to reduce injection of ~6 MHz into their amplifiers.

Also, to be clear, it's not clear to me that your problems were not the result of things external to the Class-D amplifiers you tried.

15

The RF Workbench / Re: U-LULU (Updated LULU) for 48 meters, 20 Watt Class-E AM Transmitter

« on: August 28, 2025, 0127 UTC »

While I'm here, I suppose that I should mention that the availability of some of the parts list for the U-LULU has changed. (Because, of course.)

1) The output transistor (Nexperia PHP18NQ11T) has gone EOL ("end of life", in other words, discontinued).
2) Several of my suggested possible replacement transistors have also gone EOL.

You may be able to find them at some of the distributors [Digikey, Mouser, Newark, Farnell, etc.] in 2025. 1) and 2) are in the context of the industry slowly phasing out the TO-220 package in lieu of the TO-247 and various SMD packages.

3) The 74ACT240 is, as far as I can tell, down to one supplier (TI) as Onsemi and Nexperia appear to have made theirs EOL.

This comes in the context of the industry adopting FPGAs and simple controllers, along with the continual increase in clock speeds, making discrete logic a very limited market. If someone is using discrete logic, it's more likely a single or dual-gate chip exactly where its physically needed, as opposed wiring up an 8 or 16-gate chip stuck off in a corner of the PCB. Also, these days it's 1.8 V or 3.3 V logic, not 5 V logic, so there's very little need for the whole ACT family, much less a 74ACT240, except in legacy applications (spares).

Anyway, I'm not going to re-do the U-LULU in light of the above in the interest of my time and sanity. I will eventually get around to a suggested (but unproven) alternate parts list for the bold among you to try.