Видео 74
Просмотров 654 180

New antenna system for portable operation

20:46

EFHW Power Rating Myths Part 2

22:58

Egret and Heron Chaser

10:00

EFHW power rating myths

22:58

Ground Vs Counterpoise what to use for portable and POTA verticals

28:05

A new way to match your portable-POTA-SOTA vertical antenna.

15:59

Unexpected Counterpoise Results...more is not always better

In this video we show how ground conditions can change even at a fixed location. This can affect the effectiveness of your counterpoise. The set-ups discussed are for portable vertical antennas suitable for POTA or emergency use.
Here is a link to a video showing how different counterpoise methods work.
ruclips.net/video/ohnKziocTxI/видео.htmlsi=Rc5jkoKfmQT0RYQL
You need to watch the linked video to fully understand what is discussed in this video.

Видео

New antenna system for portable operation

20:46

New antenna system for portable operation

Просмотров 4,4 тыс.2 месяца назад

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 fiel...

22:58

EFHW Power Rating Myths Part 2

Просмотров 9095 месяцев назад

The actual power rating of the 49:1 transformer core is limited by the core temperature. Core cooling is actually more important than core losses. Please watch part 1 first. Here is a link. ruclips.net/video/mev44L1Y3us/видео.htmlsi=FyFtfnkyvcb34Ekd There is a link in part 1 to get you back here to part 2. These videos show how hot ferrites cause signal distortion which then generates harmonics...

10:00

Egret and Heron Chaser

Просмотров 1806 месяцев назад

Stop large wading birds from eating the fish in your pond. You can build this water powered device to chase them away. One great egret or great blue heron can decimate your fish population very quickly. This device is similar to the "deer chaser" that is featured in many Japanese gardens. Here is a link to a video that shows the solar system in great detail. This video also shows the constructi...

22:58

EFHW power rating myths

Просмотров 1,6 тыс.6 месяцев назад

You can determine the power rating for yourself. Don't rely on myths and exaggerations. Watch these videos to fully understand this problem. This video gives you background information on power rating. ruclips.net/video/K4gGfDN5k5M/видео.htmlsi=VwWtaN6NGDnblRDP This video explains how the non-linearity of ferrites generate illegal spurious emissions. ruclips.net/video/gbmUkmrztMQ/видео.htmlsi=2...

Ground Vs Counterpoise what to use for portable and POTA verticals

28:05

Ground Vs Counterpoise what to use for portable and POTA verticals

Просмотров 11 тыс.8 месяцев назад

We investigate the various counterpoise methods for vertical POTA antennas. We learn that poor ground conductivity is actually a good thing. Be sure to watch the next video on this subject which is linked below. Here is a link to a follow-up video on counterpoise effectiveness. ruclips.net/video/hSkCFAyhVs0/видео.htmlsi=6G2cJ5pvTjYG7ib3 Here is a link to a video showing how to match a POTA ante...

A new way to match your portable-POTA-SOTA vertical antenna.

15:59

A new way to match your portable-POTA-SOTA vertical antenna.

Просмотров 1,9 тыс.11 месяцев назад

We show a way to match a short vertical antenna that provides a 1:1 SWR on all bands. Then we use WSPR to demonstrate that we can receive signals and that other stations can receive our transmissions with this antenna. We discuss the losses in loading coils for vertical antennas and in ferrites that are used in EFHW antennas. We will show a better way to make loading coils that are more efficie...

Best Vertical Antenna For Portable Operation...DIY POTA ANTENNA

13:00

Best Vertical Antenna For Portable Operation...DIY POTA ANTENNA

Просмотров 7 тыс.Год назад

The efficiency of a 1/4 wave vertical antenna can be greatly improved by getting it up off of the ground. This "do it yourself" antenna covers 20M thru 6M. The lower frequency bands can be covered by adding a loading coil at the base. This antenna is easy to set up and does not require wires or tripods on the ground. A parts list is included in the video.

15:55

EFHW emissions violate FCC rules

Просмотров 3,2 тыс.Год назад

A spectrum analyzer is used to show the magnitude of the harmonic emissions caused by the ferrite core in an EFHW antenna. These spurious emissions exceed the level allowed by FCC rules. Also shown is how to make a 50 Ohm dummy load with a -40db signal tap. Watch these videos for complete context. ruclips.net/video/K4gGfDN5k5M/видео.html ruclips.net/video/gbmUkmrztMQ/видео.html ruclips.net/vide...

EFHW Spurious Emissions Caused by Ferrite Toroids

19:51

EFHW Spurious Emissions Caused by Ferrite Toroids

Просмотров 1,9 тыс.Год назад

In this video we explore the possibility that the non-linearity of ferrite cores that are used to construct EFHW antennas are causing harmonic out of band emissions. These emissions my violate FCC rules and regulations. Here is a link to my video about the power rating of EFHW antennas. ruclips.net/video/K4gGfDN5k5M/видео.html Here is a link to my video about transformers. ruclips.net/video/i-Q...

13:51

EFHW Antenna Power Rating

Просмотров 673Год назад

We show a method of constructing an EFHW antenna for portable operation like field day, and POTA, and emergencies. Here is a link to my previous video showing the construction of the base/counterpoise. ruclips.net/video/yMYNHZ2vVMo/видео.html Here is a link to a video showing how to make a common mode choke. ruclips.net/video/KS97dorqHPU/видео.html Here is a link to the clear PVC plastic. www.m...

Mast Support for Portable Antennas for Field Day and POTA and Emergencies.

13:43

Mast Support for Portable Antennas for Field Day and POTA and Emergencies.

Просмотров 1,1 тыс.Год назад

We show an easy to make support for telescoping mast antennas for radio amateurs. This can be quickly set up by one person and does not require guy lines. The support structure can be used as the counterpoise for an end fed antenna (EFHW). This allows fast and easy set up of antennas for emergencies, for field day, and parks on the air (POTA).

Understanding Grounding/Earthing could save your life.

22:01

Understanding Grounding/Earthing could save your life.

Просмотров 962Год назад

This video describes the correct symbols to use for circuit common and earth ground and connections to an enclosure or chassis. Grounding of laboratory instruments is described and demonstrated. The operation of a Ground Fault Circuit Interrupter is explained and demonstrated. Electro Magnetic Interference (EMI) from a switching power supply is shown. The general configuration of the AC power c...

Heatsink Science or how to keep power devices cool.

26:42

Heatsink Science or how to keep power devices cool.

Просмотров 336Год назад

We explain the thermal data on device data sheets and show how to use this data to properly apply heat sinks. Here is a link to my video about thermocouples: ruclips.net/video/v4bAtDTM6Ck/видео.html Here is a link to my video about an affordable thermocouple thermometer: ruclips.net/video/La7xi1Pbz7Q/видео.html A good source for heat sink data is : www.aavidthermalloy.com

Thermocouple Meter Review; Can a $25 thermocouple thermometer be any good?

14:26

Thermocouple Meter Review; Can a $25 thermocouple thermometer be any good?

Просмотров 3,5 тыс.Год назад

This video shows the testing and review of a low cost thermocouple thermometer. Information is presented on the use of type J and type K thermocouples. A demonstration of a non-contact IR thermometer is also included. Here is a link to my previous video about thermocouples and how they actually work, ruclips.net/video/v4bAtDTM6Ck/видео.html