New antenna system for portable operation

Рет қаралды 3,286

29 күн бұрын

A unique tripod base and adjustable whip for 20M thru 6M is shown. Special two mode loading coils are explained. One coil covers 30M and 40M and a second coil covers 80M. This equipment is intended for emergency operation as well as special operations such as parks on the air (POTA).
Details are available at www.amratekproducts.com
Amratek (Amateur Radio Technology) is a new entry into the field of equipment for portable communications.

Пікірлер: 28

@jbammi 22 күн бұрын

Didn't go to Hamvention, so thanks for bringing these products to our attention. Regarding the faraday cloth: i folded the edges, and secured the fold using the faraday tape which comes with the cloth. Keeps the edges from fraying. I also purchased a grommet kit (they are very inexpensive on Amazon), punched 8 grommets on the periphery of the faraday cloth, and lay it down and stick in small Aluminum tent pegs. Keeps the faraday cloth secure and in place, and holds well in fairly gusty winds. Also, i had mentioned in another video, several people here use chicken fence wire rolls, way cheaper than window screen and available in any length you want, works well too. I like the faraday cloth best because it fold up compact and is the lightest. Also carry 4 radials as a backup.

@Jimscoolstuff 18 күн бұрын

Thanks for sharing this information.

@tomshannon3921 20 күн бұрын

Grew up in nearby Huron. Left Ohio in 1975,became Ham 40 yrs. Later. Enjoyed video,especially Lake Erie History! 73 W7OT

@Jimscoolstuff 20 күн бұрын

Thanks for your comment. 73 KQ8E

@turinskiboy 26 күн бұрын

Thank you, Jim.

@Private290 26 күн бұрын

Great video. Just found your channel. 73

@Jimscoolstuff 25 күн бұрын

Thanks for your nice comment. 73

@jaxon44a 27 күн бұрын

I like the simplicity of design, adjustability and ability to lower SWR shown in the video.

@Jimscoolstuff 27 күн бұрын

Thank you for your comment.

@rocko6550 27 күн бұрын

Excellent very good presentation. I like the dip curves

@Jimscoolstuff 24 күн бұрын

Thanks for your comment.

@DaDitDa 27 күн бұрын

I'm not a fan of PVC pipe construction. Nonetheless, nice to see this application of variable inductive coupling and integration of a matching network -- what's old is new again.

@Jimscoolstuff 27 күн бұрын

Thanks for your comment.

@Kinetic79 26 күн бұрын

Thanks for the nice walkthrough. While the stinger is a bit longer than the 17’ telescopic whip, it looks nice and robust and aluminum is a preferred material with less resistance. So if you put the capacitor in the circuit, since it connects to the tripod, it could be said that it tunes the ground system a bit (and then you further refine the total match with the inductor that’s in series with the whip)?

@Jimscoolstuff 26 күн бұрын

The counterpoise is part of the tuned circuit. The ultimate counterpoise is 1/4 wavelength radials which are inconvenient to use. A "tuner" is a matching network that uses an inductor and capacitor to present a desired impedance to the transmitter. kzfaq.info/get/bejne/pc6eft2a1Mm4qH0.htmlsi=CDqyiXUpV92J-krh Thanks for your comment.

@KA4UPW 26 күн бұрын

The ground screen off to the side like that will drastically affect the omni-directionallity of your vertical. Put the cloth in the direction you want to work.

@Jimscoolstuff 25 күн бұрын

A ground screen over "good ground" capacitively couples to that ground/earth. I have conducted tests using WSPR and wsprnet and could not detect any directional bias. When used over poor ground (like rock) you may be correct. kzfaq.info/get/bejne/pc6eft2a1Mm4qH0.htmlsi=arffHqircQ0lq18x Thanks for your comment.

@KA4UPW 25 күн бұрын

@@Jimscoolstuff Ive done extensive testing and modeling and found that the directionallity is affected. At first i thought the other directions were affected due to ground losses but modling showed the path of least resistance dominated and the signal was warped into the direction of the ground. I havent tried this over a salty marsh but i live 5-miles from the coast on relatively good conductive soil and still can see the benifits. I actually went as far as to switch in and out groups of ground radials to favor a weak signal or to null out a noise source.

@Jimscoolstuff 25 күн бұрын

@@KA4UPW Thanks for sharing this information. What modeling software did you use ? Those that I know of are poor at handling non-uniform ground configurations.

@KA4UPW 25 күн бұрын

@@Jimscoolstuff I cant remember. It was a long time ago when i lived in WI before moving to Europe. I have been in Florida for the last 10 years. So yes probably 15years ago. I did the emperical data loading up a 40ft flagpole. Then used used the long WI winter to play with and manipulate the models until i had a reasonable fit. I wish wisper was a thing back then. I think i have a write up on it on my QRZ page. I have a 68ft pole on stand-by for my current QTH here by the beach.

@KA4UPW 26 күн бұрын

Add a capacitance hat near the top of that stinger will improve the radiation resistance on 40m-80m

@Jimscoolstuff 25 күн бұрын

That is true. Thanks for your comment.

@OdieInAz 10 күн бұрын

I assume the 80m slider will also tune 60m, 40m, and 30m?

@Jimscoolstuff 9 күн бұрын

No, the 80M slider will not work on higher frequency bands with a standard 17 foot whip. It could be made to resonate by using a shorter whip, but a high SWR may result due to the very low radiation resistance of a very short whip.

@jbammi 20 күн бұрын

I assume i can leave the coil permanently attached to the base and the stringer to the coil., and when i want to use 20 thru 6M i just bypass the coil with a clip lead. That way i can also switch quickly between 20 and 40M, Kindly confirm that this wont pose any harm to the coil? 73 de k1jbd, Bammi

@Jimscoolstuff 19 күн бұрын

Yes you are correct, and the coil will not be harmed. 73, KQ8E