NEW products, EFHW-7510-2K, and 7510 wire assembly

We added a new product, An EFHW-7510-2K antenna which has low SWR at 75M (3.9MHz) while maintaining the same characteristics on bands above like 40,20,17M… etc, just like EFHW-8010 model does. For upgrades, we sell 7510 wire assembly in 14 AWG wire too for those who want to just switch the wires on their existing EFHW-8010 antennas. The links are here:

EFHW-7510-2K antenna

EFHW-7510 wire assembly

Summer break 2019 at MyAntennas.com

MyAntennas will have a summer break (again). It will last from July 4th till August 15th when we will resume the shipping of products sold on our website during the summer break. We are working on additional inventory so we will be able to clear all orders very fast after the reopening on August 15th, 2019.

ZF9/ZF2XA Cayman Islands

It has been a year since I have visited Cayman Brac Island (ZF9) and operated as ZF9/ZF2XA in CQ WW WPX CW contest. The antenna was EFHW-4010 set as inverted, actually lazy L right at the beachfront taking advantage of salt water and partial vertical polarization of an antenna. The 2000 contacts were made with ICOM 7300 and 100W over the weekend during this small DXpedition, 73 Danny, E73M aka N4EXA & ZF2XA

Summer Break 2018, June 28th – August 4th

Summer Break at MyAntennas.com

As we did last year this summer break will last from June 28 – August 4th when we will resume shipping the products sold during the break in order as they were received.

Some design and experimental work will be done during that time at our Contest location-E73M in Bosnia.

I am looking forward to hearing you on the bands, especially those using our EFHW antennas.

 73 Danny N4EXA/E73M

 

2017, another record year at MyAntennas.com

As expected 2017 was another record year at Myantennas.com with thousands of products shipped to 106 DXCC countries all over the world. Our products are becoming very popular among HAMs with great positive reviews resulting in growing demand for EFHW antennas and CMC’s as our bestsellers.

This morning on January 2nd, 2018 we were surprised with another cold day in Florida with temperatures plunging down to 5 deg. Celsius forcing our “Santa” mailman to wear the cap and fleece while picking up the “presents” accumulated over the new years weekend.

I wish you all Happy New Year

Danny Horvat, E73M, President Euroxpress corporation

MEF-107-2k+NEW High Power EFHW transformer for 1-7MHz

The MEF-107-2k+ is new high power EFHW antenna transformer(~50:1 ratio) designed  with massive 1.25 pound (0.57kg) ferrite core, equivalent of almost six (6) 2.4-inch toroids and very low insertion loss for frequencies from 1-7MHz

Insertion loss measurement S21 with two back to back transformers shows only 0.18dB (4% power loss) at 160m and 0.28dB (6% power loss) on 40m bands.

Insertion loss for MEF-107-2k+

Field Day 2017

The FD 2017 is just around the corner.  During the Field Day, 2016 many used our popular EFHW-8010 and EFH-4010  models and reported excellent results. This year we added many products to our website including installation plates  (pole, tower etc.) for our EFHW-1K version as well as EFHW-HP version.  Recently we added a transformer  MEF-330-HP  (used in EFHW-8010-HP and 4010-HP models) as a separate item for those who want to build their custom EFHW  antennas  75m  or use at the MARS frequencies etc.

 

Good luck and enjoy this year field day event!

Shipping DXCC award, almost!

It has been just little over two years since  MyAntennas.com started its production operation in Florida.  Being avid contester and DX-er I wondered how many countries (DXCC) we ship our products to in these two years. Well, with the recent addition of Barbados (8P) we placed a pin #97 at our DXCC world map. See the image bellow. 

 

73 Danny N4EXA aka E73M

NEW CMC-130S-3K

The new CMC-130S-3K  is an economy version of already popular CMC-130-3K  with 0ver 5000-10000 Ohms of CMI (Common Mode Impedance) or ~40dB attenuation in 50Ohms systems on all HAM bands 160-10m

Priced at $59.95 it greatly outmatch any similar size product on the market.

 

NEW! 2kW ICAS Broadband transformers and EFHW antennas

After few beta testers, we started building and selling two new transformers capable of 2kW ICAS.

The new transformers MEF-330-2K (3-30MHZ) and MEF-310-2K (3-10Mhz) are the product of the constant search for best designs in order to satisfy the need of some users wanting a reliable EFHW antennas capable of withstanding the longer periods of transmission with high power without overheating the transformer which results in a change of Ferrite material.

It is known that every RF broadband transformer has insertion loss which converts to heat into ferrite core which after reaching its curie temperature (not saturation) changes the properties of transformation ratio and results in elevation of SWR of the antenna.

These two new transformers use ferrite material with higher curie temperature and larger cores in order to dissipate the heat easier than smaller transformer like MEF-330-1K (1kW ICAS version).

Results are great, MEF-310-2K has an only 0.14dB loss on 80 and 40m  while MEF-330-2K average the loss of 0.55-0.6dB from 3-30Mhz.

New antenna model, EFHW-8010-2K is already in production and will satisfy many users wanting to use them in CW/Phone “rag chewing” style of operation as well as DXpedition and contest style of operation.

The new duo-band model EFHW-7540-2K will come out soon with unique feature covering the 75m (3.8MHz)  and 40m (7-7.3MHz) bands without use of traps and only 110ft long. It will satisfy many users wanting to have single wire antenna capable of legal power on phone part (75m) as well as the whole 40m band with low SWR.

Stay tuned and Happy Holidays,

Danny Horvat N4EXA aka E73M

EFHW 1500W capable transformer MEF-330-HP

It has been a long search for suitable materials and quite a few experimenting has been done to design a high ratio (~50:1) transformer for EFHW antennas capable of high power (1500W ICAS). In the same time,  it was hard to cover the wide range of HF spectrum from  3-30Mhz, yet I did it again!

I am proud to announce that new transformer MEF-330-HP is almost double in size of  its little brother  MEF-330-1K and also has a bit less insertion loss on all frequencies between 3 and 30MHz. A new transformer will be incorporated into new/old  EFHW antenna models EFHW-8010-HP and EFHW-4010-HP as well it will be sold separately for those who want to make their antennas for use out of HAM frequencies for their needs such as MARS, Marine or EMCOM activities.

New models can be seen at these links EFHW-8010-HP and EFHW-4010-HP

Also, see this short video of testing the antenna with a new transformer at 1500W.

73 Danny Horvat, N4EXA aka E73M

 

New line of single band Dipoles MY-DP-160-10M

MyAntennas.com is launching a new line of single band Dipole antennas for all Bands from 160-10m.

Dipoles are featuring:

  •  high-quality PBT material housing for 1:1 BALUN wound with PTFE coaxial cable capable of at least 3kW ICAS on all bands.
  • Stranded #14 AWG black tinned wire with simplex wire clams and black high impact insulators.

Removable Simplex clamp on ends allows for easier adjustment of dipoles resonant length  Models can be seen on the link here https://myantennas.com/wpproduct/my-dp160-10m/

dipole-160-10m-9  dipole-160-10m-8

CMC- Common Mode Choke as noise reducer video by AC0HF

I have been writing about great results I and many others had with the use of CMC- Common Mode Chokes as noise reducers when inserted in your coaxial lines. Many CMC’s  have been sold by MyAntennas.com and many positive reports came from happy customers. Please see the great video report  by AC0HF who demonstrated reduction of noise averaging a 3S-units (18dB).

We have received reports from few with results of 5 S-units  (30dB) and more of reduction of noise.

73 Danny N4EXA aka E73M

 

 

EFHW-8010-Is this the ultimate ‘magic’ antenna?

 Is this the ultimate ‘magic’ antenna for HF? This is the question I found at some forum topic named “Smoke and mirrors, or electro-magic”

Well, until all popular antennas such as G5RV, ZS6BKW, CHA-250, 43-foot verticals, End Fed long wire with 4:1 or 9:1 UNUNs, Open wire Doublets, Skyloops, etc.  magically evolve into 8 band resonant antennas with VSWRs of 2:1 or better across all 8 bands, with matching loss (insertion transformer loss) averaging at -0.66dB  from 80 thru 10m….then…

YES!  EFHW-8010-1K is ultimate MAGIC antenna!

There is no BIG secret about EFHW-8010 antenna, it is just wide band low loss transformer and a piece of wire. Yes, there is a coil at few feet from the box but it is NOT TRAP, it is not secret as well, actually everything in this antenna was published  and patented by few people a long ago. First, my countrymen, Nikola Tesla patented this transformer almost 120 years ago in 1897, then another HAM, Josef Fuchs, OE1JF patented half wave radiator with a variation of Tesla transformer almost 88 years ago in 1928.

Tesla Transformer
Tesla Transformer patented in 1897

Various versions of End Fed Half Wave-EFHW dipole antennas ( some with a very high matching loss) were introduced by radio amateurs in last 80 years including mine with best-designed broadband transformer and “Compensating” coil. This small coil is almost invisible at 80 and 40m bands but due its position and value makes a nice impact on current distribution on high bands.

For example, an EFHW-8010 antenna is half wave resonant on 3.6MHz, its fundamental 8th harmonic is 28.8MHz  but due Velocity of wave propagation on copper wire (with insulation), real 8th harmonic is above 28.8MHz. same applies at 7th harmonic at 25.2Mhz and 6th harmonic at 21.6MHz.

Well, this small coil makes the wire look longer on high bands, therefore moving a resonant point of 6th, 7th and 8th harmonic within amateur radio bands. Simple and effective. Oh, by the way,  I was not even born when this technique was published in many amateur radio publications. I simply love to implement known old techniques into new designs.

So, at the end, I am sometimes puzzled how HAMs tend to glorify some mediocre antenna designs but quick to dismiss good ones. I wonder what would be the next big mystery about EFHW-8010 antenna. I guess it is time for “Counterpoise” mystery. In the meantime ask yourself (and Google), does resonant circuit such as half wave resonator needs “extra  circuit/counterpoise” to operate.

Stay tuned!

73 Danny Horvat, N4EXA aka E73M