Yes, you are correct. The signal is very directional in the SE direction, because the power line that runs from the pole to my house is the same direction. no doubt, the RF is following the power line. 😉

Y porque Comentarios en espanol?

@@bob4analog distinguido. Su. Video. Es. Muy. Instructivo. Para. Los. Que. Defendemos. El. Medio. Radio. También. Me. A. Gustado. Inventar. Un. Poco. Fui. Técnico. En. Electrónica. Hace. Varios. Años. Me. Hice. Al. Español. Para. Que. Pudiéramos. Leer. Los. Comentarios. De. Los. Que. Vemos. Los. Videos. Saludos. Mr

You are correct. MOTs are designed for constant load as with uW ovens and irregular mains voltage. Terrible power factor too, and they need air flow as they will get Hot. Not exactly ideal for linear amps, but they will work, just not well regulated as you stated. 73

Thanks! Yes, it should work. A balun shouldn't be needed, but maybe a similar method of matching like the gamma match shud work. I haven't worked with 18 mhz, so i don't have a sure answer. I just made this antenna, coz i wanted to see if i cud load into a grounded radiator at 27 mhz, and it worked.

It's not my station, i just made the vid of it. But thanks for the advice just the same. 👍

Thanks, glad you liked it. The input was ~973 mV, which is what the amp was strapped for. However, i was able to increase the gain by bridging the 1k shunt resistor with a 680 ohm, which is now ~320 mV for full output. www.circuitbasics.com/wp-content/uploads/2016/10/LM3886-Datasheet.pdf

QRM is rediculous these days and there's no excuse for it. Sad that our regulatory agency (FCC) has allowed it to get to this level. Doesn't appear they're doing anything to stop it either. 73

Thanks, glad it works for you. Yeah, they charge WAY too much for their Range Extender! Especially after i seen the circuit, i was convinced that it's pitifully simple and would be easy to build. Just a thot about the Hopesun meter; the output of the tuning meter circuit may cause the meter to pin. Therefore, you may have to add a trimpot of some kind to adjust it. Otherwise, your meter is a great idea and would be far easier to read than the tiny meter i used on mine. Hope you can make a vid of yours, would love to see it. Let's get the word out. 😉👍

@@bob4analog Yes I noted the difference in the meter scale. Certainly I'll share a video of how mine turns out.

Relax, Frank.. take a chill pill!

@@bob4analogI'm all out, however, I'm getting ready to look over my part 15 setup, look at better antenna options.

Rogers on that 😃👍 kzbin.info/www/bejne/qaupmXmvntKXirMsi=hrfLBW9-VxYmpKdw

Former radio station owner here. I had an FM and 2 AMs; real stations, not part 15. Yeah, I'd be careful using made up call signs. I've dealt personally with the FCC, and they don't play neither do they smile!

Altho it is interesting that the fcc does not regulate the content of transmission. For it is written, "Content of the broadcasts are not restricted by the FCC regulation." wnaram.com/2021/04/part-15/ 😉

The hum/buzz issue you mentioned maybe a phantom hum. Are you hearing the hum off air? Is it a hum or a buzz? I've had the same issues with mine. The perceived Hum and buzz is usually caused by power line noise being superimposed on the received signal. It's not being put back in the transmitter. It's very misleading. One of the biggest offenders are cell fone chargers. They make a lot of electrical noise that gets into the 120v house power and interferes with AM reception. Usually, it's only heard around the house, but I don't hear it on the car radio. I've installed plug-in AC line filters at the offending sources of noise and it mitigates the hum buzz problem. I'll also recommend grounding the transmitter to a solid electrical ground post or a metal cold water pipe. AM transmitters usually need a good RF ground. You're also correct about TR304. I made a mistake when i called it TR308.

The popping sound was likened by many to a finger being pushed and pulled out of a bowling ball. 😆 ya never know, it's crazy enuff to be just that. Hope you get in touch with Jeff. That would be interesting to know how they got that sound.

Pluged into what, an amp?

Indeed. While this might be true, it's kinda referred to as an AM modulator, much the same way an "RF Modulator" seems to refer to a coverter that goes between your tv and your vcr. So, technically, it's not an AM modulator. However, check this out... ecedmans.files.wordpress.com/2014/03/am-modulators.pdf It's all relative. 😉

Well, you caught me on this one. 😊 I wasn't real concise, as I was in a hurry to get the video finished and was mostly for illustration. You are correct, the coil is a LSA680-470. I reshaped it by squeezing the coil until it was round. Then I used half of a round ferrite with a nylon screw epoxied to the end of it. The design itself is not critical. You can use the LSA680-470 coil and just slide the ferrite bar in and out to tune it. Experiment with the different taps on the coil to get the best tuning. The heart of the circuit is mostly with the RF transformer I mentioned in the video. Build it, it should work fine. 😉👍

Glad to hear the mod worked good for you! Also just added another vid on how to make the talking house outdoor antenna.. kzbin.info/www/bejne/qaupmXmvntKXirMsi=V5TiHi3EIBW50bjx

Thanks! Dam shame the state of AM radio. It's survival (or lack of) has become a political mess, when it shouldn't be.

The MW and LW are being abandoned because the broadcast transmitters use so much power ... maybe they could have some ( legit ) amateur slots ? ............ DAVE™ 🛑@@bob4analog

Yes, could be for the hams at some point, also for the hobby broadcasters under the Part 15 FCC rules. Right now, it's all up in the air.. nobody seems to know what to do with it. I still think there's hope for AM, only time will tell. Let's hope for the best! 😉👍

Glad you liked it. You might also like the mod I made on the Transmitter: kzbin.info/www/bejne/bZ62i6FrmLWLa6csi=EUASfJmfJoUDEFk2

Yes! 😉

It's a broadcast hobby. It has very little to do with how AM sounds, but that it's legal under Part 15. Not sure if this is what you were addressing.

This is geared towards people that restore antique radios. It is nice to have an AM broadcast source to be able to enjoy them once they have completed the restoration. If you are not aware antique radios, were around before FM radio was even invented.

Not sure i know what you mean by hi fi mod, but the modulator mod in this vid superceedes anything the the newer Talking House transmitters have, which i demonstrated in the vid. However, if you're referring to audio processing, no. The only thing discussed in this vid was modifying the modulator in the transmitter to obtain the best possible modulation comparable to real AM stations. Audio processing is a seperate issue and left up to the user to decide on using. However, there is some great software processing designed for AM that works great, like Stereo Tool ( www.thimeo.com/stereo-tool/ ) or the free version ( www.flux.audio/project/stereo-tool-freeware/ ). Hope this helps. 🙂

@@bob4analog yes it helped a lot that you

About a mile out, we could barely hear it, but the effective range is more like 1000 feet or so. It did pretty good for Part 15.

Call letters are just a gimmick, they're not official. We traveled bout a mile and could barely hear it, but the effective range is probably more like 1000 feet or so.

The range is low partly because of poor ground conductivity. I'm not trying to put anyone down . Installing these low power transmitters directly to a metal fence isn't a good idea, it tends to weaken the signal. High power AM stations rf energy is totally shielded from the Earth . The towers sit on ceramic insulators ,including all feed lines such as audio . The best way to mount low power transmitters is on PVC pipe or non conducting pipe . If the feed wires go underground , then place them in PVC pipe that are glued together to prevent water intrusion . Braid two wires two wires together , one wire can be used for the Earth ground lightning protection and the other can be hooked to a small radial system , maybe an inch below the surface . The Earth ground wire should have a surge protector . The fence does provide a good counterpoise but the antenna by what I can tell in the video is only an inch from the antenna ,. The RF will couple with the fence and weaken the signal . The Rangemaster box appears to be metal , that too will connect with the metal fence and weaken the signal. The transmitter doesn't have to be located really high above the fence , maybe a foot . Part 15 am transmitters can generate a very sold signal and cover many miles but it really takes a massive effort to accomplish it . People underestimate part 15 transmitters because of such low power .

4 or 5 turns is good. As long as the resistors don't get hot operating on 28mhz, its good.

I am using a Kikusui COS6100M 100 Mhz Oscilloscope with 2 x10 scope probes. I connect channel 1 to the audio source, and channel 2 to the RF output, then press the X-Y button. This makes the trapazoid pattern. Both channel input levels may need to be adjusted on the scope to display a good trapazoid pattern. - RF output (Pin-12 MC1496) to scope Vertical input - Audio source (Pin-1 MC1496) to scope Horizontal input Here is a pic that shows more on how to set up your scope for trapazoid: www.tpub.com/neets/book21/0130.GIF Hope this helps.

Thanks friend @@bob4analog

I did the mod on i think it was a 4.8 and a 5. I dont remember moding a 4.6. It may be slightly different, but not much. From what ive found so far, all the TH models are based on the same schematic, so they're all similar. Do you have a 4.6?

@@bob4analog I don't currently own any TH device. I am considering purchase of a TH 5.0 and was curious if that version suffers from the same design deficiencies as the one you modified.

@@N2Stooges @N2Stooges I have mod'd a TH5. The 5.0 design does have increase bass response which was a good idea, but their design still suffers from a couple of shortcomings, like the lack of flat frequency response to 10 khz, insufficient PA voltage to make full 100% modulation, and the antenna auto-tune issue. The mod i made solves those issues. It completely bypasses the internal audio compressor, which gets in the way of adding your own audio processing. It's pretty much a straight, flat audio path from the input to the modulator, and it works. The test results i did in the vid demonstrates this.

I've looked thru my files and i did modify a 4.6M version. I don't know if there are sub versions of the 'M' suffex, but i did varify the the 4.6M is virtually the same as a 5. Ive got pics of the boards and other mods is you would like, I'll send you those. [email protected]

Dunno, sorry, never tried it with the Kinter. ¯\_(ツ)_/¯

Is he bass?

@@relicofgold that "choppy" rhythm part... and assorted licks.....guitar... and maybe bass as well.... and, of course, the outro...

24v shuld be ok since the IC is rated for 26v max. The electrolytic capacitors in this amp are rated at 25v, so it's good. 👍

@@bob4analog so far so good I have not done the heat sink mod yet as the data sheet on the IC said it was not required for a 8 ohm load which is what I have hasn't got warm at all yet been on over a hour at half volume which is very loud with a set of polk T15 bookshelfs

That's great! Glad it worked for you. Congrats! 😉👍

Good question. Under normal circumstances, a 1/4 wave ground plane is an ideal antenna and does not need anything for tuning it, just the proper length radials with the ground radials at the proper slope. However, such an antenna will behave differently mounted on the ground as opposed to on a pole in the air. The ground plane antenna i made is mounted on the ground, which caused tuning issues. That's why i made the tuning network, which demonstrates how they can be used to midigate such issues. The half wave dipole you spoke of is a good antenna too, but it's feedpoint impedance is generally around 72 ohms, not 50, which is ok, but it will cause a higher SWR. Also, if your dipole is horizontal and not at least a 1/4 wavelength from the ground, this too can contribute to higher SWR issues. These are just a few issues that can cause matching issues with antennas. 🙂 73

@@bob4analog ten four, thanks.

So true! I borrowed the optimod, i don't own it. Yes, stereo tools is great. I'm using that now. 👍

@@bob4analog I unfortunately received a Model II (which has a Model III board), there's probably not a lot to be done to get better audio out of the thing, but I mainly just play old time radio shows through it, no music.

As i recall, there's not much difference in the TH boards. If the board in yours looks similar to the 1 in the vid, i think it can be mod'd the same way. I can send you some detailed diagrams if that will help. [email protected]

@@bob4analog email sent

@@bob4analog sent you pictures of the board in mine, it's similar, but has some components yours doesn't have, and mine lacks some components yours has. I take it that the black box on the board on the tuner is some kind of ferrite choke or something?

I have ch-1 on RF output and ch-2 on audio input. My scope has an X-Y switch, that when selected, displays a trap pattern.

Good point, thanks for sharing that. 👍