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Messages - Kage

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Medium wave is so easy to get on with minimal parts these days yet somehow I still over complicate my designs because I end up working around bin parts I happen to have on hand instead of purchasing what I need. Still happy with my 25 watt AM TX though that is class E utilizing a single IRF640 and the commonly found 3 chip PLL frequency generator circuit. That FET requires quite a bit more drive oomph though so I ended up using a totem pole bipolar circuit ahead of it, also didn't have proper fet driver chips on hand.
Then I went and got weird and modulated it with series class A instead of D and of course the heat sink for the modulator is the size of the rest of the transmitter including the PA that runs cool on a tiny slab lol.
Oh well, it gets the job done.
Your design is nice and clean, definitely a pro level build. Too bad I didn't see this a year ago when I started work on building my TX.

PS: I was wondering what I was going to use my set of 4 T130-2 cores for that didn't work out the way I intended for an 11m EFHW antenna, now you're making me want to fool around with another transmitter build or maybe linear PA for something to use them in :P

10/11 meters / Re: 27.385 Mhz
« on: October 30, 2019, 1656 UTC »
Same here in the midwest. Wish I had SSB on my transceiver but nice hearing some skip again especially after I got my antenna back up.

Equipment / Re: Antennae Maxims
« on: October 27, 2019, 2359 UTC »
4. You are an antenna
My antenna erection sure turned me into part of one the other night from those wonderful end fed standing waves.
Now what about the Gooch?

Yeah I know TL;DR. I was just ranting. Just angry about the solar cycle I guess :P

Ever since I was a kid I wanted to be a radio DJ. I built small FM transmitters as a teen starting out with rigging in audio to the internals of another FM radio and using the local oscillator to rebroadcast a few houses down from mine. Grew up and pirated FM with higher power, got up to 10 watts or so on FM and a 40' tower. Covered most of my town. Had friends come over and we'd do shows and had the local Taco Bell guy a mile away call in just to hear his voice echo over the cell phone and his radio.

I got paranoid after a while and part of that was my own doing trying to get the word out and I was always getting high and/or drunk at the time. Had a bad cough syrup habit but that's another story. Anyway.. after learning not only did my friends know about our FM station.. the whole damn town knew which surprised me. Doesn't help it is a 11k population so word gets around, but not in the way I wished.

So I switched up, went to AM because my strength is electronics and having fun with electronics. Got on medium wave and still have it setup for the occasional power switch flip to start broadcasting. I'm saving it for winter though when conditions are best and FCC is stranded.

Thing is the lack of interest now. Radio in general is dying. Any of us who deny that are clinging to memories. I sure know I cling to those FM days in the late 90s to 2008 or so. I had a lot of fun then and we had a ton of listeners. I had a phone patch, aka: cell phone with cord spliced into the mixer, but hey.. it worked!
My point here is the medium itself is dying because in general most broadcasts on AM/FM are talk radio and music, and not good stuff. It's all syndicated garbage, no local calls, no requests.

Us pirates aren't doing so great either in my opinion and I know I will take hate for this but I tune into shortwave on 69xxkHz and it's always the same boring music I can get on FM radio, the DJs don't talk much and some of them resort to computerized voicing.
What happened to broadcasting with actual talk, maybe a friend or co-host? No offense to those who don't, I believe everyone with the ability should get on the air, but the programming has become stale lets face it. We get out our tablet computers or phone to see what song is playing if we don't know just to type up a reception report. Yeah hooray you emitted RF and we could hear it. There are some really good pirates still around and I won't name names, but they can carry a program and often blast a radio. So if you got low power make that programming count or else you just become another log note.

Sorry I don't mean to sound like a dick. I just remember pirates of the 90s and so, there was more effort rather than running a play list. I say this because I realized that is exactly what I was doing with my AM radio station on 1710kHz. Wondering why I didn't get more listeners, then sat back and thought... would I continue listening to this just because it's on the radio? 

I'm just wondering what is the way forward? I seem to be going backward with AM now instead of FM broadcast band pirating simply because it's literally getting to the point where FM radio has killed itself and no one wants to listen to Hotel California one more time without shooting their brains out. At least AM offers more fun, which is so damn backward when you think about it. What has become of all this?

Equipment / Re: 9:1 or 49:1 unun for end-fed long/random wire?
« on: October 16, 2019, 1404 UTC »
I'll get a 9:1 unun,and use a suggested random wire length to avoid half-wave and it's multiples then,that sounds like the best things I can get out of this setup.
I was only thinking about the 49:1 due to the random high impedance spikes a random wire can produce,and I tought it would be easier to match a super low impedance than a too high one.
Actually,the old one did a fairly decent job for me.Especially on the higher bands,where the 30m wire was at least 2x wavelength.It is true that it has some directivity,it may be deaf in some directions,and it may perform really well in others.
I don't want to live with this one antenna forever,but right now this should be fastest and easiest way to get on the air with somewhat decent signals.
Thank you for everyone,I can't wait to install it and see the results  ;D
If you have a facebook account check out the group EndFedHalfWaveAntennas. Don't need to be a ham to join. They focus mostly on the non-resonant type EFHW transformer and antenna designs and are very active.

Equipment / Re: 9:1 or 49:1 unun for end-fed long/random wire?
« on: October 16, 2019, 0249 UTC »
The "9:1 UNUN" are for random length wire antennas fed at the end. 49:1 or other high ratio transformers are for resonant "cut to frequency" antennas like the traditional zepp/fuchs antenna.

Generally the 9:1 has far more loss as the transformer/core takes on heat to make the non-resonant antenna be of any use across wide bandwidths and are often deaf across some range of frequencies because of the nature of a random length of wire. A tuner will help with that but introduces even more losses. Worse yet people who know no better will think they are performing great because they always show the user a good SWR, but remember even a dummy load shows good SWR  ;)
They have the benefit of being quick to throw up in the air and will get some signal in/out but are inefficient compared to resonant single/mono band antennas.

If you want a high performance monoband EFHW antenna you should always go with the 49:1 UNUN and cut the aerial to half-wave resonance and almost all your power into it gets out since it acts exactly as a traditional dipole, with the exception of being fed at the end.
The ratio doesn't need to be 49:1 2,400 ohm either, other ratios will transform to other impedance. Generally an EFHW will be in the range of 2,000 to 5,000 ohms at the very end of the dipole when resonant.
I usually go with a 3.2k transformation wire winding ratio of 8:1 which is a final impedance conversion of 64:1 (50ohm * 64 = 3.2k ohm). Antenna diameter and height above ground makes a difference here. Generally the fatter the radiator the lower the final impedance at the end. Thin wires might need as high as a 81:1 out at 4k ohm. Remember the large ratio number is the coil winding ratio squared, so for a 9:1 wire winding you end up with a 81:1 impedance conversion, not to be confused with a 9:1 UNUN for non-resonant types that convert to ~450 ohm.

Whew think I typed that all correct. Check out http://www.aa5tb.com/efha.html for info on the traditional high performance resonant EFWH.
For random wire non-resonant types plenty of plans and examples exist online but keep in mind there is no free lunch as they say, being non-resonant and wideband means they might perform as good as a wet noodle on some bands and somewhat acceptable on others, but any wire in the air is better than nothing.

Equipment / Re: To weep hole or not to? That is the question..
« on: October 12, 2019, 2227 UTC »
Any penetration on top of a "weatherproof" box is a potential failure point.
If you decide to go with a weep hole, make sure it is small enough to prevent entry of yellow jackets, spiders, etc.
Looks like I typed too soon. After a little reading it sounds like a weep hole is actually required because a perfectly sealed box will build up condensation. After pushing the top of my old match box into a glass of water there was no leak. Looks like the few tablespoons of water in it built up from condensation alone over the seasons since I didn't build it with a bottom weep hole.

Now the question is how large of a hole? My match unit is small since I am using a toroid this time instead of air coil so guessing it won't need to be any larger than a coffee straw opening, small enough to keep bugs out for sure. Wonder if that might be too small?

Equipment / To weep hole or not to? That is the question..
« on: October 12, 2019, 2103 UTC »
Replacing my old EFHW antenna match box I built a few years ago. It progressively climbed in SWR slowly over time until it became unusable.
Took down the vertical today and disconnected the box, opened it up and you guessed it.. water came gushing out.
Thought for sure I had that thing waterproofed well with RTV silicone but the antenna mount bolt is on top so rain ran down the antenna pole on top of that bolt and nut and somehow worked its way through the bolt threads into the box even being on there as snug as I could twist along with sealant.

So would it be advisable to make my new box waterproof with some other method/sealant or have a bottom weep hole to let water out?
This raises another issue in that humidity could get through the weep hole causing its own damage so not sure which is better practice in proofing it.
Luckily my coax didn't get water down it, or not enough to damage it but I definitely checked it with a dummy and meter to make sure and crossed my fingers.
I'm worried if the weep hole is at the bottom which is where my coax will connect that it will let water out which can then drip towards the coax connection. Thinking of maybe gluing a tiny tube into the hole so it runs past the connector

Ugh Midwest weather season is brutal on antennas  ::)

Huh? / Re: Rip Taylor is dead.
« on: October 07, 2019, 0405 UTC »
RIP Taylor

The RF Workbench / Re: Stretchyman 40w GaN TX is sick
« on: October 07, 2019, 0354 UTC »
And this is why I don't sell my old homemade transmitters to people. I've been asked before but always feared something like this would happen and I don't even build on a professional level like stretchy does. Oh those multiple pops... sure someone wasn't making microwaved popcorn in the other room? I could use some reading this thread.

Huh? / Old TV reception phenomenon
« on: September 27, 2019, 1057 UTC »
Many TV repairmen from times past have a story many of them have experienced along with some ordinary TV viewers while alone where when tuning the rabbit ears and touching the antenna just right they would see the usual signals of distant stations go out of sync.

Once in a great while through the rolling signals they would see a fuzzy or oddly distorted colored live video of themselves, or even childhood memories or family events that would roll up the screen only for a moment that could never quite be tuned in before it would vanish to static. Only problem is there were never any video cameras or recorders in the room and the image seemed to come from a position in the room or past event where no camera could possibly be.

Most people who have noticed this phenomenon would refuse to tell anyone about it in fear others would think they've gone crazy and often couldn't shake the creepy feeling that something unexplainable is watching them while they watch it.

Equipment / The greatest radio ever, teh Bell Howell 9 band prise
« on: September 23, 2019, 2146 UTC »
I spelled teh on purpose.
Yeah here is all the glory of this $1 radio I just bought at the thrift store. It has world band, so... You know how radios are, if it has shortwave you have to buy it because we're suckers.

Well this little goofball of a radio covers medium wave from 530 to 1610kHz or so, talk about a killer for me. I listen to the X band AM mostly. To make things a little more gentle though it does have a barn door IF stage which makes AM listening like listening to FM if you don't mind going out into the deep woods to hear a broadcast far away from your local 50kw. It's easy to modify though to cover up to 1710kHz as I found by a simple adjustment on the 4 gang capacitor variable, but don't expect the readout to be right of course.

FM is even better, it actually performs as good as my breadboard FM radios. It almost has the ability to have selectivity if you hold it just right.

Oh and did I mention shortwave? This has the feature but I think they forgot to enable it. I picked up Havana and oooooh weeeee!

Okay I'm giving this little radio a harsh time. It's cute, performs okay for camping, and for being a radio that was a gift if you purchase other crap prizes on TV then voila. It at least has no birdies and after opening it up and damn near breaking the antenna connection from only removing the cover that is held together by... get this... ONE SCREW, and clips, I adjusted the 455kc oscillator and touched up the 4 screw tuning capacitor for peak. It's on par with dollar store gizmos and well it had shortwave... who will let a cheap radio with shortwave sit around for $1? Gumballs cost that much these days. I say we replace gumballs with shortwave radios!  8)

BTW that arrow pointing to that screw, that is literally the ONLY screw holding the thing together, it's all plastic clips  besides that one real loooong screw lol.

BTW there is one good thing about my playing with this stuff, I learned about toroidal cores and what the numbers mean. Sounds silly to the experts I am sure, and honest to God I have built RF electronics and it took me this long, but now I know the first number means size, the next number means mix. I feel like such an idiot lol. We all learn something new every day. Built radio transmitters for years but never knew that lol, just went by frequency spec, or tested them the hard way  by winding equals and sending RF through to see if they'd pass it, but I was over-complicating things like usual. Though it doesn't hurt to do the wrap and test method to test, never know if these companies sell legit core material until hitting them with RF.

Going a bit nuts here as usual from my manic state of mind.

Been researching to replace my DIY resonant fuchs 1/2 wave end fed antenna for 11 meters. Original design I used was a 1:8 ratio coil with two windings primary and 16 secondary going into around 15 or so pF capacitance using of all stupid things a trimmer cap. Well I learned my lesson with weather and rain using this as a base antenna. Thought I had it waterproofed but every rain or humidity would climb SWR and lower frequency. NP0 trimmers are useless in outdoor weather and moisture.

This time I am going with a straight up lumped LC tuned stage, long story short there are three kinds of these end fed antennas for 1/2 wave end fed feed, the fuchs (better known as EFHW transformer coupled pri:sec transformer, sometimes resonate air core or powdered iron core, or non-resonate on ferrite which is lossy by a dB or more for multiband but gives flat SWR at expense of low efficiency and energy transfer). The single coil tapped version to convert a range of 1:6 to1:9 ratio (50 ohm to 2500-4700 ohm end fed), and my current setup which simplicity wins for efficiency the LC coil, a coil in series with transmitter output to antenna input and a capacitor across antenna to ground to convert current to voltage fed. There has to be very little loss using this method because it's direct and no cores used or lossy link coupling.
I think the drawback is the fact it isn't linked coupled will cause more standing waves on coax back to the shack.

With CB radio and 4 watts of power, got to make every watt count!

My question here before I complicate shit more is how many people have used these? I know the Antron/Solarcon a99 and other antennas use the same exact thing. The 99 uses an LC coil/cap, one coil inside of the other to act as a hairpin impedance match but I'm not even sure it's really that, it just looks like an RF coil to ground so that the antenna is connected to ground for static, otherwise the A99 is a simple LC match network into a 1/2 wave wire.
Here is an article on the A99 deconstructed to show how overpriced hype this thing is, it's literally an ordinary LC coupled half wave end fed...

I love EFHW antennas because the simplicity of mounting being in a small lot, got to use whatever I can. Wire types allow inverted V and other configs too.

I'd love to know if using an LC with a 130-2 toroid is as effective as an open air coil at 27MHz. I am testing both but can't figure out which is less lossy. The toroid seems to give less SWR across the CB band which leads me to believe it has a bit of loss, so I am currently testing with house copper stripped wire to make my coil, and a coax stub for the high voltage capacitor.

It looks ugly as shit right now but so far it tunes up with ~1.2 SWR over 26.5 to 27.5MHz but the coil is so sensitive to size change, it will take some glue to clamp it and lots of RTV silicone to seal it up before connecting the top bolt to my 18' adjustable 1/2 wave conduit pipe in the air...

Not even sure how well the open air core copper coil will do. Seasonal changes here are extreme and rain got into my last "fuchs" coil match which led me to this simpler design. I want to use my 130-2 toroid donuts for this but I feel they have some sort of loss at CB since they technically are good to 10MHz on the paper, no idea how to calculate loss over air wound when used as purely an inductor like this.

After this coil cures the RTV silicone I plan on making the same coil but using the red 130-2 coiled torroid in place of the air coil design in a different water proof unit with snipped coax capacitor and compare the two. Hard to do at my location because CB is dead right now. Hoping to get some skip in with that short spirt in wintertime. I guess there is always field strength metering. If torroidal wins out or comes in equivalent I think we just found the new best DIY end fed design for goofed setups like I have. Though only a few hundred watts can run through them, but I honestly run barefoot and enjoy the challenge of antenna design over idiotic power into thimble antennas.

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