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Reviews Categories | Antennas: HF: Yagi, Quad, Rotary dipole, LPDA | Cushcraft XM240 Big Thunder 40 meter Monoband Help

Reviews Summary for Cushcraft XM240 Big Thunder 40 meter Monoband
Cushcraft XM240 Big Thunder 40 meter Monoband Reviews: 15 Average rating: 4.2/5 MSRP: $999.99
Description: Cushcraft's XM240 monobander utilizes rugged Big Thunder hardware that combined with high strength aluminum tubing affords the antenna outstanding wind survivability. Phillystran boom trusses are used in the XM240 design for extra boom stability. The feed system is a 50 ohm direct feed with dual driven elements. VSWR is flat accross the band. A high power 1:1 balun is included.
Product is in production.
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You can write your own review of the Cushcraft XM240 Big Thunder 40 meter Monoband.

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KB3Z Rating: 5/5 Jun 29, 2019 11:21 Send this review to a friend
It Works!  Time owned: 0 to 3 months
I really like the antenna. I had a Force 12 Delta 140 which gave me great results. But having 2 elements does make a difference. The only issue I have is that when the SWR was measured on the ground the resonant frequency was about 6.8. The reason is we set the element lengths for the CW portion of the band. But when we installed it at 60 feet, the resonant frequency is about 7.1. The swr at the lower portion of the band is at about 2.7:1. I decided that I would just use my HF Auto to deal with that.

But to constantly tinker with the measurements would have been a real nightmare for the person that installed the antenna for me. He did mention that before you wrapped tape around the coils and that had an effect on it. Of course now, you don't have to do that. I hope that Cushcraft reads this review or someone who has experienced the same thing would let me know why this happened.

Other than that it is a great antenna!
WR0F Rating: 5/5 Apr 9, 2016 11:00 Send this review to a friend
1 year later AWESOME   Time owned: more than 12 months
I have now had my XM-240 beam up a full year .The beam has done very well stateside and working dx 67 feet up. You do not have to be up 100 ft for a 40 meter beam .
We set the antenna at mid range to cover a good portion of the 40 meter band on swrs .
I did put the DX engineering 1:1 5kw balun on it instead of the standard 1:1 and dx mast clamps for 2 inch pipe . With the better clamps the antenna has not moved in 80 mph winds .
I can highly recommend this antenna to those who want to improve on the 40 meter band with a beam for under $1000 .We purchased ours @ 819.99 from + shipping cost
WR0F Rating: 5/5 Mar 28, 2015 20:33 Send this review to a friend
Heavy Duty Brackets   Time owned: 0 to 3 months
I am still in the process of putting this antenna together but comparing the construction of the XM-240 to a earlier version cushcraft 40-2cd is a breath of fresh air.
I had a 40-2cd up in the late 80's and this antenna has been beefed up on the element brackets and size of the boom.
We also added the DX Engineering DXE-SDS-200AP Super Duty Clamps 2 inch for our 2 inch mast pipe that others have recommended and the bolts they recommended . We had to drill 1 hole for each clamp for the mast clamp to fit my 2 inch mast pipe with the new Clamps instead of the larger u bolts .The boom does not need any modifications as each boom section has a bolt in it to keep it from rotating .
There is no doubt this antenna will be a winner for years to come.
VE9OX Rating: 5/5 Apr 16, 2014 11:57 Send this review to a friend
Great Big Antenna!  Time owned: more than 12 months
I have had my MFJ XM-240 Big Thunder up at 74 feet for almost 3 years.

Typical front to back ratio exhibited is 15db with good forward gain.
You can easily hear a big difference when turning the antenna against or toward strong signals.

I use mine on CW and SSB from 7.000-7.200 Mhz with a Palstar 5K manual antenna tuner between the XM-240 antenna and my HP amplifier to ensure safe 1:1 SWR.
If you don't use an amplifier, use your radio's auto tuner instead.
If you use the upper SSB portion of 40M, then assemble the antenna for that part of the band.

I did not use the balun supplied by MFJ.
I purchased a 5KW rated DX Engineering heavy duty specialized Yagi balun instead.

All stainless hardware is stock.
All heavy duty brackets and good quality elements are supplied.
I preferred to use two small Gates Hose clamps (instead of one) on the end elements.

I tuned it to mid-band for my preference.

The SWR is as Cushcraft (MFJ) advertised without the tuner.
Of course with a good tuner, it is possible to realize a 1:1 SWR from 7.0 to 7.2 Mhz.

The instruction manual is good -no problems to report on the assembly process.
I put the beast together in a day on a 2" dia 4 foot mast pounded into the ground to measure the elements carefully.

Be certain to measure approximately 2 Ohms across each of the 4 coils before it goes up your tower for proper "Q" to ensure good forward gain and proper front to back ratio.

What a huge difference from using a dipole or an inverted V or a vertical or even two phased loops!

This is an excellent performing monoband 40M Yagi antenna make no mistake.
I am usually one of the first to break through the pileup using this antenna IMO.

K0ZR Rating: 5/5 Jul 15, 2013 17:47 Send this review to a friend
Great Performer  Time owned: more than 12 months
My XM240, pre-MFJ, has been at 70 ft, or more, for two years now. No problems. It performs beautifully. I am able to do quite well in the pileups; surprisingly good performance for a 2-element, shortened yagi.
N8CL Rating: 2/5 Mar 6, 2012 13:07 Send this review to a friend
Inadequate hardware  Time owned: more than 12 months
I have had the XM240 up at 90 feet for two years, and the mast plate hardware does not prevent the beam from spinning on the mast. We are about to make a second trip up the tower to install a new mast plate with DX Engineering Super Saddle Clamps. For a few dollars more CC could have provided a decent clamp. The electrical performance of the beam is fine, but mechanically it lacks. If you buy this beam, at a minimum use DXE Super Saddle Clamps or fit it with a Hygain cast mast clamp. And forget about asking Cushcraft for help.
N6WIN Rating: 5/5 Oct 19, 2011 07:47 Send this review to a friend
Great in the contests  Time owned: more than 12 months
I bought one of these used and mounted it at 70'. I am continually impressed with it during the contests. DXing has become a lot funner with it too. My Elmer has a 40m rotatable dipole from Cushcraft at the same height a mile away... I feel louder with the XM240.
AI0O Rating: 2/5 Jul 25, 2010 20:02 Send this review to a friend
very sloppy construction  Time owned: more than 12 months
I put up the XM-240 3 years ago. It worked very well for the first year. Soon after that the swr was infinite and the antenna showed resonance at 20 mhz. After tramming it down we found the following defects: No continuity across the loading coils, loose screws at coils, boom to mast bracket was underdesigned, and catenary was inadequate. I would advise anyne putting one up that was purchased since MFJ bought out Cushcraft to make the following mods before putting it up in the air: Use DX Engineering super duty saddle clamps for boom to mast attachment - throw away the cheap u-bolts, beef up the upper catenary bracket, it bent under the weight of the beam, cut back heat shrink tubing at loading coils and clean enamel off coil ends, replace sheet metal screws with stainless machine screws and stop nuts. It is a good performer but too many corners are cut during manufacture.
N6KD Rating: 0/5 Jun 7, 2010 08:25 Send this review to a friend
Parts unavailable  Time owned: more than 12 months
I have a XM240 here that has been in the air for several years. This winter, the antenna got damaged - so ordered some new parts from MFJ - Cushcraft sold its ham antennas to MFJ. I ordered parts on Mar 15, 2010 - have called MFJ parts numerous times - been promised parts several times - but never received them. After 4 months, I am giving up. They do not have parts and are not manufacturing them.
Will look at the M3 40 meter yagis.
PY1BR Rating: 5/5 Sep 2, 2009 08:50 Send this review to a friend
Great antenna  Time owned: more than 12 months
After 9 years I moved to a new QTH where the X240 is already installed and working as before, excellent performance. Although the previous QTH was close to the sea its mechanical parts are in excellent conditions. I still live in a big city so this antenna is the best we can have installed in a top of a building. Before install the XM I was working with a simple dipole. Now a new horizon is opened. It seems like with the dipole no propagation at all and with the XM the opposite.
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