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Topics - Antennae

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The RF Workbench / Heathkit DX-40 tube transmitter
« on: December 04, 2022, 0147 UTC »
Does anybody happen to know if the Heathkit DX-40 will transmit outside of the ham bands?  An acquaintance of mine who is into ham radio has found one and they want to test it.  But they only have a crystal that is around the 43m band to use on their dummy load. 

Also, they want to test to see if the "phone" mode works but they don't have a microphone that fits the older style mic out jack. They were wondering if they could just temporarily wire up an mp3 player to the + and - leads of the mic.  Would that work? 

On the Half Moon Bay SDR in CA receiver there's some music on 6920 am.  It was a spanish american sounding song.  Then I also hear it at Radio Ranch SDR in AZ.  I can't help it, there I was, minding my own business and this music was there at noon my time. It used to be a rare occurance but I haven't been listening for pirates lately. 
I hear some heavy rock, kind of sounds like Korn. 

20:29 Station ID... it said something something station
Then it audaciously started playing some more music. A little like techno music but with more of a human element.
20:45 ID "Radio" something "a" something "station"
pretty good music.  Good propagation today. 
22:45 Station ID, "Radio Prisco?"

S5 signal level.
I hear Nirvana. Interference from some radar.  Its nice to hears some pirate at 9am on Easter on the West coast! Thanks stranger. 
1619 ish I heard the operator say its not an unidentified station. And he mentioned something radio.  Heavy metal music.
1629 very clear "Two Dog Radio" ID
1638 morse code inteference

General Radio Discussion / HF Global Weekend in October?
« on: October 18, 2019, 1550 UTC »
Hello, can anybody verify when the Global HF Weekend is going to be? 

When the weekend goes on, what are some good places to listen? 

For Sale / Wanted / Barter / $75 Used / not working 40w GaN transmitter
« on: September 26, 2019, 1834 UTC »
I've got a venerable Stretchyman 40w GaN transmitter for sale.  It worked great on the upper 80m ham band to make contacts where I never used it for pirate purposes. 

Its broken, it doesn't transmit.  It made popping noises when I plugged in my AC to DC 24v power supply while the unit was on. I  should have plugged it in with the the power supply and the transmitter off,
then turned on the power supply,
and then turned on the transmitter. 
Stretchy offered for me to send it back for repairs but if somebody will buy it as is, its more convenient for me.

Comes with the frequency programmer and some files for a few frequencies.

PM me if you want to do paypal.  Cost around $300 new. 
Sell for $75 with shipping in the continental US.

Equipment / 80M home brew Mag Loop VS. inverted L comparison
« on: September 22, 2019, 1645 UTC »
I've had this big 9' magnetic loop in 2 pieces made out of plumbing copper pipe and I never had a good way to test it.  With my newly acquired ham ticket I was able to send out a carrier wave and listen to remote SDRs across the Pacific.  It was 630am for me and about 1130pm for Australia's East coast.  The propagation conditions were not changing for me yet.

I wanted to see how far this big magnetic loop would transmit compared to an inverted L . 

The inverted L is about 30' high and is terminated into a tuner and a ground rod. Its length is cut for the upper 80m band. 

The magnetic loop has an adjustable air capacitor and it sits on a brick above my lawn.  It has a length of coax used as a capacitor in parallel to bring my air capacitor into the range of 80m.  The small loop hooks into some coax which goes into the same  tuner on the same ground rod. 

1st test: 50w carrier.  I had them both up one morning and the inverted L was about 1 S-unit stronger than the magnetic loop into Freeman's Reach, AU and Marahau, NZ.  They were fadey and near the noise floor.  AKKY, in Fukushima, Japan did not pick up the mag loop, but it picked up the inverted L at the S-2 noise floor.  The signal was so low that I could hear it and hardly see it on the online remote SDR. 

I wondered if the inverted L was resonating with the loop. I didn't expect much from my magnetic loop.  It has clean connections, but I figure it has loss compared to those fancy vacuum variable loops on the internet.  And it doesn't have a ground wire system.  It goes to the tuner, then gets grounded at the rod there.  Anyway I had to do another test. 

2nd test the next morning.  30w carrier.  The mag loop was tuned a few kHz away from the test on the inverted L to prevent resonation.  (when testing the mag loop it might charge up the inverted L and that would transmit as well. That would throw off a nice scientific test because the antennas wouldn't be isolated.)  I tested the inverted L, then I took it down, and then tested the loop.  The signal was about the same into Freeman's Reach, AU. Near the noise floor, fadey carrier.  There was interference in NZ, and i didn't test Japan (I was still sleepy. maybe I did test it and didn't write it down? we will never know, unless I do another test tomorrow). 

I don't know which one is uglier for the neighbors. The tall pole? Or is it the large loop peaking over the fence with a big air variable capacitor on it?  I spray painted the loop camouflage and its now less noticeable until you do notice it, then your mind messes with you because you know its a circle but you can't place it easily because its broken up with camo colors.  If you don't know WTF it is, its more scary because I'm trying to hide it from you, neighbor.  And I'm up at 630am on a Sunday messing with it.  And talking sweet things to it. "Thaaaaats a gooooood girl." 

So, the loop is about 1 S-unit weaker than the inverted L and they both make it all the way across the Pacific.  But its hard to tell, they're pretty close.   Pretty dang cool, mang.  Its the not so little loop that could.

The RF Workbench / Stretchyman 40w GaN TX is sick
« on: September 22, 2019, 1532 UTC »
I have a Stretchyman 40W transmitter I use for communications on the ham AM band. Got good reports BTW.

So I hooked up my 24V powersupply into the  TX and it made a couple pop noises and then it quit working.  The PS is an AC to 24V DC converter.

I think I may have had the transmitter "on" and my PS was "on" when I plugged the PS into the TX. 

It made a pop noise in the past, so I've been plugging them together with them off.  Then I first turn on the PS, and then I turn on the TX.  But I didn't do that this time and now it doesn't work.  I checked the fuse and its good. 

Any ideas whats wrong? Maybe I can replace something? 

SDR - Software Defined Radio / Used SDR pricing (Elad FDM-S2)
« on: September 10, 2019, 0252 UTC »
I've got my Elad FDM-S2 I'm about to sell.  Does anybody have an idea what its worth? It works great, looks great, comes with box.  It was around $600 new a few years ago. Thanks in advance!

General Radio Discussion / 7 Hz reciever
« on: February 07, 2019, 2354 UTC »
I found a video where some guys made a receiver to hear Schumann Resonance frequencies down around 7.8 Hz. There are audio samples in the video.They use a loop wrapped with 6000ft for the antenna:

Huh? / Ion pumping cords
« on: May 12, 2018, 2159 UTC »
Welp, there are instruments that detect the human aura (I learned it off of youtube).  And there are instruments that can balance your vessels from Chinese medicine.  They're called ion pumping cords. A cord is a wire with leads on either end and a proprietary germanium diode in line.  You tape magnets to your accupuncture points, south side toward skin.  Then wire up your body and it helps you out.  Has anybody tried this? 


Huh? / Any theories on Havana Mystery Sound that causes damage?
« on: October 12, 2017, 2351 UTC »
So I figure the mystery sound that hurts diplomats in Havana could have a cause that is radio related.  If anything, its wave related. Does anybody have a theory what would produce audible sound to people inside their homes?


Huh? / I DXed my garage door
« on: September 23, 2016, 1621 UTC »
I drove away from my home today and realized I didn't close my garage door. I knew that the first click would have more juice than subsequent clicks. I was tempted to click it through a chain link fence, but I saved my precious first click. It was all I had to keep me from turning around.  So I backed up to a clear shot, held the clicker high, and it worked! 

North American MW Pirate Radio / UNID 1630 AM Sept 20th, 7am 2016
« on: September 22, 2016, 1620 UTC »
Welp, I saw this video and thought that I could record this here. 

Looks like its in New Jersey. Nice reception. Computerized voice.

Equipment / LoG receive antenna, Loop on Ground!
« on: September 12, 2016, 1628 UTC »
Its a loop flush on the ground. You can also phase the things for directionality!  Cool shtuff, mang.  Check out the website with pictures:

The RF Workbench / Modulated 5W NS40
« on: September 02, 2016, 2012 UTC »
I met a guy at a bar a few months ago and we were talking about the FM radio on the shelf. Anyway, it ends up he was a ham.  And at the time, he had a 5-10W transmitter that was meant for morse code, the NS40:


He mentioned that he modulated the NS40 transmitter using the schematic shown below.  He's been testing it on a dummy load using an .MP3 player with pre-recorded speeches of him giving his callsign and calling CQ.  He said he could get audio out.  Also the audio is copied better if its compressed and limited.  But he doesn't think its modulating very well and he wants to know why.  He told a sad story of how his favorite car audio amplifier was destroyed.  It was a 100w amp.  He used an .MP3 player as input and he kept turning up the amp's output that went into the transmitter.  Eventually he was getting good power out as shown by the swing on the tuner's meter. But the amp got hot and died.  Any idea what might be the problemo?

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