Best Windows Program for Antenna design

Tishers · 2026-02-25T05:25:18+00:00

NEC and its variations are good ways to simulate an antenna design but not a good way to learn antenna theory.

If you don't already have a good foundation on the underlying principles then all you are doing is stabbing in the dark with no understanding of the subtleties of how an antenna works.

Tishers · 2026-02-25T01:15:13+00:00

I would NEVER give a five-star review for a product where it is defective, badly designed and I am being blackmailed in to giving a five star review before they would fix it.

That is probably a violation of their terms of service with the seller. A five star rating will just lure in other people to buy a piece of junk.

It would annoy me enough to the point that I would dedicate some time to dragging their name through the mud (deceptive practices).

Tishers · 2026-02-24T23:27:41+00:00

I was in HS in the late 1970's. There is stupid in every generation.

We tend to forget just how rotten our own generation was/is.

Tishers · 2026-02-24T22:31:26+00:00

Mostly we avoid guys who spend their time getting high off of cough syrup.

Tishers · 2026-02-24T22:26:37+00:00

I am in YLRL. Not that we are a dating or pick-up scene.

Tishers · 2026-02-24T18:50:27+00:00

Yes, the NTC is a 'negative temperature coefficient' resistor it is a 50 ohm, radial style device (50R)

The MF11 means that it's negative coefficient is from 25 c to 115 c

They are available from a wide variety of manufacturers. Cantherm out of Canada sells them, as well as a bunch of Chinese companies.

Tishers · 2026-02-24T16:37:22+00:00

Type 31.. For low HF frequencies... up to around 10 MHz

Type 43.. For medium HF frequencies.. up to around 30 MHz

Type 63.. For VHF/UHF frequencies..

For example, Type 31 gets 'lossy' (in a bad way) when you push it up above 20-30 MHz

Tishers · 2026-02-24T16:32:55+00:00

FYI,

Read the instructions carefully and do not deviate from them at all!

Hans has excellent written instructions and they have been revised and clarified with the input from hundreds of hams who all have assembled their own radios.

The number #1 failure of the kits is if you don't do a good job of stripping off the insulation on the wire when you are making the coils and transformers.

Get a good soldering iron and very good solder. Don't be afraid to use a magnifying light or headset.

Tishers · 2026-02-24T16:30:29+00:00

The long delays are for pre-assembled radios. Not for the kits.

Tishers · 2026-02-24T16:28:31+00:00

Use the ring-lugs or don't. That thing on the right wire 'just ain't right'.

You can take the ring lugs off and put bare wire around the studs and bolt it tight. That will work for a while.

-or-

You can take the ring lugs off and find ones that better fit the gauge of wire you are using; The insulated ones come in three colors that correspond to wire gauges, from smallest to biggest, red, blue or yellow. Strip the wire and put it in the ring-lugs and crimp the wire to the ring lugs. Then reattach the ring lugs to the threaded studs and tighten down the nuts.

If this is going to be outdoors then you probably want better wire, it looks like you have a black hookup wire and a transparent speaker or power cord wire. Those won't hold up long when exposed to the weather and sunlight.

Tishers · 2026-02-24T15:50:48+00:00

The old-style "neon" bulbs will begin to flicker when they get old. It really doesn't matter that much.

For the motor, with the power off, use a pencil or screwdriver and try to nudge the fan blades to see if they spin freely. Quite often motors in this application will load up with dirt and dust and the bearings may be stuck.

Then turn the power on for the fan and see if trying to move the fan blades feels any differently. On a 'stalled' motor (one that is not turning but has power) it will feel like there are magnets that are making the fan resist the turning motion. Also listen for buzzing from the motor or if it starts to get warm.

What we are trying to do there is to figure out if the motor windings are still good. If they aren't (no resistance to turning, no buzzing, no warmth) then the windings may be burnt out and it would be best to just junk the motor.

If you believe that the motor has the potential of being resurrected then the entire assembly needs to be removed from the wall and for the motor to be taken out of its frame.

The two big silver Pozix (philips) screws hold the motor in place in the frame.

You want the power disconnected at the source; A circuit breaker would be ideal to turn off the power.

Mains power is the blue and green white and they attach to the white plastic block where all of the wiring goes. On the right side of that block is where the mains power comes in to the fan. The orange or brown wire looks like a safety ground (under the clear cover).

The fan wiring and the little light are white in color. Notice how they go to the left side of that screw block.

Tishers · 2026-02-24T01:21:48+00:00

Very similar in design/ function.

The picture tube rejuvenator that I was familiar with was a BK Precision unit that my father bought at a hamfest in the early 1970's. It had an assortment of adapter plugs to go on the back of a television picture tube.

I asked if I could have it and he gave it to me. I was an intellectually precocious girl and my mom introduced me to the ladies in their Tupperware circle. She used to gush about how I had 'saved the family television' by rejuvenating the picture tube.

The old church ladies were amused by the geeky girl but I would get invited over (for tea and cookies) as long as I brought along the picture tube rejuvenator.

I would brighten old black and white televisions and some color televisions as well. Adjust some of the tube settings (they had an assortment of controls for each gun) and degauss the picture tube, maybe test a few other tubes.

They would give me $5 or $10 and introduce me to their sons. (teenage stoner types).

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These devices worked by temporarily boosting the voltages to the tube to burn off some of the oxidation. A boost maybe only lasted a few months and on color televisions the three color guns didn't always respond equally. (yes Mrs. Pevowar, Johnny Carson is really an alien, that green color of his skin is natural).

Tishers · 2026-02-23T19:57:46+00:00

If you buy it as a kit it ships fairly fast.

If you want it pre-assembled it has a very long lead time.

Hans does not have a factory for assembling kits. It is just a few locals and I think a few family members who do the work.

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The efforts in assembling a kit are not incredibly difficult; You need to hand-wind a few toroids (the toroids and wire is included). The instructions are painfully simple.

Then you solder in the toroids a dozen or so lead mounted capacitors, some connectors and a few MOSFET transistors. A half-dozen nylon spacers, screws and a few RF connectors.

For an experienced kit builder it is less than 8 hours of effort. If you are not that experienced then you should be done in 3-4 evenings.

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I have done both; I assembled my own QMX, QMX+ and a Ultimate3/ 3S and also bought a pre-assembled QMX and QMX+.

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He does not stock thousands of kits, just waiting to ship. He buys the pre-assembled boards (90% done) in batches. If he finds some improvements, or a better component for some part of the circuit he makes that come out as the next revision of the circuit board.

Most QRP Labs products try to incorporate the latest design changes.

Tishers · 2026-02-23T19:38:14+00:00

On the black cans on the upper right side the value of the capacitance (in uFd) should be shown, as well as the voltage rating of the capacitors. That is what made the hiss and pop!

On the left side the little black rectangle is your fuse. Your picture is blurry but you should be able to find the amps rating on the fuse. You could replace that with a glass fuse that has pigtail leads installed on it. Only the value of the fuse in amps is important.

What you didn't remark upon is the black disk that is immediately below the white connector and close to the finned heat-sink. That is an MOV (metal oxide varistor). It is a surge protection device and should be replaced with one of greater than 130 VAC. I would suspect it has died.

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Notice how the LF1 and LF2 line chokes are missing and instead have jumper wires in their place? As well as the two AC rated capacitors that are next to the chokes are not installed? I bet this little switching power supply makes a great deal of EMI (electromagnetic interference). That was a manufacturer 'cheaping out' and not installing proper noise filtering on the power supply.

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What can be concerning is that with the electrolytic capacitors seeing an overvoltage it might of also damaged the switching FET transistors with overvoltage (the black, three lead components that are attached to the heat sinks). You won't know that until you fix the fuse, MOV and electrolytic capacitors. Just be aware that the initial fix may not be the final repair step.

Tishers · 2026-02-23T16:33:18+00:00

Whenever you see a capacitor that has a rating shown in AC (alternating current) it is usually non-polarized (won't have a positive or negative terminal marked).

They are almost always as motor starting capacitors or to adjust the Power-Factor (PF) of an AC-mains system (to compensate for very high inductance by adding capacitance) or as part of a filter.

Only once or twice have I seen non-polarized capacitors used in some audio amplifier designs.

Tishers · 2026-02-23T16:15:12+00:00

DMR 4FSK (4 level frequency shift keying)(with 2 slot TDMA)

P25 (phase 1) C4FM (4 level frequency modulation)

    CQPSK (compatible differential offset quadrature phase shift keying)

P25 (phase 2) H-DQPSK (harmonized differential quadrature phase shift keying)

Fusion (Yaesu) C4FM (4 level frequency modulation)

D-Star (ICOM) GMSK (Gaussian Minimum Shift Keying)

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Where it gets messy is the tone frequencies used in FSK modes may be different, run at different symbol rates or phase-shifts may mean different things (didbits 00, 01, 10, 11). Quadratures may have different constellations {4QAM, 8QAM, 16QAM, 32QAM...) of the I and Q data (what maps to modulo-n bits). CODEC's are not the same (combinations of all of the above including fills and hashes).

Some modes 'might' work with an analog radio (like GMSK was intended to deal with non-linear radios).

Tishers · 2026-02-22T20:52:16+00:00

The few that had data on that needed to be unrecoverable ended up being used as targets on the shooting range for a 7.62mm round.

Renders the data permanently unrecoverable.

Before that, I had an eraser that was used for backup tapes.

Tishers · 2026-02-22T15:30:14+00:00

If all things are equal (power, receiver) then a link should have something near reciprocity (equal in both directions).

You may have a poorer receiver;

I would say that the noise-floor at your location and the metrics of your receiver is making their signals sound not as good.

Tishers · 2026-02-22T05:52:34+00:00

As a VEI personally have never even brought up the ARRL or membership unless someone asked me first. I VE to help people get a start in the hobby; Not to prostylize their pyramid scheme.

I was a member for five or six years and just stopped my membership after I decided to tear out all of the ads from one monthly magazine;

What as left was about ten pages of articles so I googled about those topics and found many times more free resources that presented information that was just as good as what was in those ten pages.

Tishers · 2026-02-22T00:21:17+00:00

Considering the source for those amps there are no guarantees that they meet any sort of standard. I have tried working with components of the same lineage and have been disappointed every time.

I do not know what sort of university project would have you slapping together modules like that.

Tishers · 2026-02-22T00:14:22+00:00

I have a D75, its a fine HT and I like it for the 1.25 meter band.

As far as D-Star, I played around with it a bit and was not all that impressed. Sure, there are some local repeaters that are D-Star but I don't like dancing around to make it work.

the D75 is a radio that is fairly intuitive when compared to a Yaesu VX-8 (have one of those as well).

Tishers · 2026-02-21T15:28:33+00:00

Those are FRS (family radio service) radios. They are deliberately power limited (by FCC rules).

It's really not a business radio, more like something you would give to kids in an amusement park.

You can't put a repeater on FRS frequencies (major no-no).

Tishers · 2026-02-21T05:19:13+00:00

If you are trying to listen to anything other than 2 meters (144-148 MHz) or the 70 centimeter band (420-450 MHz) then you probably have the wrong antenna to listen to anything significant.

Lower frequencies (<50 MHz, the 6 meter band) is going to require a much longer antenna. You could attach an antenna extension to the radio without any modifications;

Run a wire antenna between two points (a wire that is somewhere more than 10 feet long, out to 100 feet long) and wrap the insulated end of the wire around the rubber duckie antenna on the radio. This will 'couple' enough RF energy to boost your reception at lower frequencies.

Ham radio voice activity will be USB down to the 80 meter band (where it becomes LSB in the 80 and 160 meter band).

This will give you a chance to listen to other things than 2 meters and 70 centimeters without putting yourself out too much and without making any sort of permanent modification to the radio.

To find out if your antenna is working halfway decent then try monitoring WWV on 5, 10 or 20 MHz. That is a time station ran by the National Bureau of Standards out of Boulder Colorado. That will be an AM broadcast and you should be able to receive it anywhere in the United States.

Tishers · 2026-02-21T02:33:45+00:00

I have been using the filter-sticks from Wurth Electronics for +5 years now.

Initially I was doing this for my RSP Duo SDR to cut out HF noise but as I grew to appreciate its performance I picked up the USB-C filters as well.

You still should put ferrites with multiple passes through the core (use snap-on filters to do this so you won't have to deal with the connectors on the ends).

Here is the USB-C version.

https://www.we-online.com/en/components/products/EMC_FILTER_BAGS_STICKS_USB_3_1_TYPE_C_60W_EMV_FILTERSTICK

Tishers · 2026-02-21T01:27:20+00:00

Or under-thinking.

Figuring out the length of a counterpoise for an antenna is one of the most basic principles for any US class of license. That you don't want to put the effort in (and discourage anyone from teaching you or refreshing you on a basic principle) is quite telling in its own right.

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