49:1 EFHW Antenna 40-10M 100W
Product Code: U9gy75R
Units in Stock: 8
49:1 End Fed Half Wave Antenna 40-10M 100W Version
Bands of operation 40,20,15 & 10m using 67 feet of our UV, Ozone resistant Antenna wire.
Power handling is 100 watts CW / SSB & 25W Data modes.
The 49:1 End Fed Half Wave Antenna is very popular choice for home & field use, Ideal for limited space and stealth applications.
This type of antenna is very easy to install because there is no need of a high feed point like a dipole antenna.
Another advantage is that the antenna can be used on multiple amateur bands.
These Antennas are designed to be tuned for a half wave length on the lowest band of operation 40m.
Then Harmonic resonances will occur on the multiple half-wavelengths of the wire on 20,15 & 10m.
30m, 17m, & 12m Maybe tuned via an ATU This may or may not work depending on your setup.
These antennas can support Horizontal, Vertical, Sloper, inverted V, Inverted L Configurations.
Tuning of this antenna.
The wire is a bit longer to allow for tuning to your desired frequency.
Tuning depends on height above ground and nearby objects.
There are so many ways to install the wire so experiment away.
If using for portable use at many locations it's best not to trim the wire back,
But to simply fold it back on it's self & Tape the wire together to keep it neatly in place.
Wire length can be calculated by the following formulas:
Length (feet)= 468/Frequency (MHz) or
Length (meters)=142.5/Frequency (MHz)
If you find you need to move the VSWR From the CW portion of the bands to the SSB portion & help
get the VSWR lower at the 10m band you can try formimg a Compensation coil 1m along your wire from the 49:1 Transformer.
This is done by using a pvc former of 19mm or 25mm diameter & around 5cm long in length, Wind 5 turns of your antenna wire on to the former
& recheck the VSWR you can add or remove turns until you get your desired VSWR over the bands covered by this antenna.
There are various videos covering compensation coils on youtube & the use of them with End Fed Half Wave Antennas.
Grounding at the lug next to the SO-239 connector is recommended !
If being used at your main shack & at power levels higher than 100W RF Grounding is recommended.
As the rf earth connection is really the other half of the antenna & will give the radiating current
more to work against on a good rf ground,
It has the same effect as placing a mirror under a candle for your radiated rf from the antenna.
An RF Ground helps to cure high voltages, Stray RF in the shack, Common mode currents & other nasties we don't want in the shack
upsetting the use of our radio equipment.
Long wire antennas tend to collect electrostatic charge (usually when the weather is stormy) which can produce ESD (electrostatic discharge)
at the end of your coax cable and damage your equipment, So RF Grounding where possible is very important to consider when using these types antenna.
Type: End Fed Half Wave Wire Antenna.
Frequency: 7 - 30 MHz
Power handling is 100 watts CW SSB & 25W Data modes.
2 X FT140-43 Stacked Cores.
Impedance 50 Ohms.
Wire Length 20.421 Meters.
UV, Ozone resistant Antenna wire.
Made in the UK by M1ECC Antennas.