40M Two Element “Shorty 40” Yagi Comparison

The Cushcraft XM-240 gets great reviews even though some have derided the coils

I have a neighboring town Ham who has one of these for sale – and so its hard to pass up. This antenna has gotten great reviews – and besides a short time when Cushcraft was sold and transferred to MFJ, the reviews are all 5’s. There has been some discussion regarding the Q of the coils.

There is an article out there where a well known contester (W6NL) took an XM-240 and replaced the coils with Moxon style end capacitance loading. Its a really cool idea, but since I am not a contester or super DX-er who wants to squeeze every last drop of F/B and bandwidth, I’m not too concerned. I also found a Canadian Ham who did an evaluation of the coils and found that they weren’t worth replacing – that either keep the coils or go with the W6NL mod. For me, I’d just leave the original design. He did say to replace the silly self tapping coil screws with bolts – and I would do that.

The Mosley SF-402-A seems to be the best value, and is the smallest of the pack. It also has one really important characteristic – it doesn’t require trusses as the Cushcraft does. It also is the lightest – which is important – since the AB-577 is a big mast rather than a very sturdy lattice type tower. HOWEVER, my N6BT had a 28′ boom and was much heavier, so I know for a fact – any of these antennas can be supported by the AB-577 and well within safe limits – a lot more than the behemoth N6BT DXU-32.

The N6BT antenna might be a step up from the Mosley and still be reasonably priced. The DXU-32 I had was an excellent antenna – very well built and stayed up and worked like a champ for a couple of years. I am going to bet that the JK antenna is very much like the N6BT antenna. In fact, JK purchased Force-12 from the fellow who had owned it for a while – Innovantennas. Supposedly, JK Antennas have updated the old Force-12 line. JK gets great reviews as well – and he has great reviews on his technical support for antennas out in the field. I can’t justify the M2 or Optibeam due to price and what I would expect is expensive shipping. I will get a price for the Mosley SF-402-M – Mosley fans seem to love their antennas. The Cushcraft antenna – if offered for a great price would be really hard to pass up – HOWEVER – the trussing part bugs me a bit – I guess I would still at least go over and check it out.

I’ve also thought about the UrbanBeam – I would actually keep it and stash it away for the next 1.5 – 2 years. I expect that we will turn the corner as far as going from Cycle 24 to 25 next year, and then after that the higher bands would open up. The big problem with the 40M 2 element yagi – is I would kick myself if 3Y0I ends up being heard and workable on more than 40M – like 30 and 20M, and I don’t have an antenna up for those bands.

I am getting 4 more AB-577 tubes – which makes pondering about the 40M 2 Element Yagi worthwhile

I have a lot to ponder – and luckily no hurry to make a decision. But I know for a fact that there is no band that comes close to 40M for me – its a DX producing band every day, every month, and every year throughout the Solar Cycle – in fact, without it – I would have completely shut down my station at the bottom of Cycle 23 – when I was in hot pursuit of DXCC Honor Roll.

QRP with the Elecraft KX-2 and chasing DXCC – maybe 300 entities seems very possible and would take a long time – and would be a great challenge – I am really liking this idea.

The easiest thing to do is get the UrbanBeam up 15 – 20 more feet and see how it performs. That’s the path of least resistance. If I purchased my neighbors XM-240, I could stash it away and put it up when the spirit moves me – in the mean time I’d “Do nothing extra”.

More thinking required . . .

2 Comments on “40M Two Element “Shorty 40” Yagi Comparison

  1. While the Moseley comes w/o a truss support, IMHO it could use one. Plus, center loading coils are not as efficient as end-loading. The XM-240 does not need a truss either, supposedly, but benefits nicely from one, especially if or while tramming it up. I quite often build one that is independent of the mast, supporting the boom during tramming, & not losing any mast height once installed. YES, to replacing the self-tapping screws w/SS machine screws, however! 73 Don K4ZA Tower Works Charlotte NC

    Liked by 1 person

    • Thanks so much Don – I really appreciate your expertise in this area. All of the antennas I listed look great, so it’s hard to make a decision. Your input helps a lot!

      Like

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