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Author Topic: MFJ 1672 antenna  (Read 1107 times)
DAVIDVD59
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Posts: 122




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« on: January 28, 2008, 07:18:00 PM »

Has anyone ever used a MFJ 1672 shorty screwdriver antenna, and what were the results? I do not see a listing for it in reviews.
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K0BG
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« Reply #1 on: January 29, 2008, 06:28:35 AM »

Length matters! Within reason, if you double the length of an HF mobile antenna, you increase the radiation resistance by a factor of four. The ratio is the same if you're shortening the antenna. Plus, the shorter the antenna is, the more inductance it takes to resonant it. This causes the coil resistive losses to increase at a much higher rate than the change in radiation resistance. As a result, a 5 foot antenna will have an efficiency about 1/6th that of a ten foot one.

To directly answer your question, the MFJ is about as good as an ATAS 120. Yes, you'll make a few contacts, and you might even be happy with it. One thing's for sure, driving around with a dummy load for an antenna will either sour your feel for HF mobile, or make you yearn for more.

Alan, KØBG
www.k0bg.com
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DAVIDVD59
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« Reply #2 on: January 29, 2008, 06:42:17 AM »

Thank you for your reply, the length issue was what I was wondering about in my mind and its efficiency.
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N5EAT
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Posts: 175




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« Reply #3 on: January 29, 2008, 12:20:10 PM »

I've read this antenna is basically the Little Tarheel 2.  If so,  I have the little Tarheel and it's a wonderful antenna.  You can put a longer stinger on the antenna. You may lose 6 and 10 meters when you do this, but that's.......ok.   When 10 is really opened up, the 3 foot stinger will do just lovely.  Some will tell you it won't, but ignore them.

I have done tests with 3 and 5 foot stingers on the Little Tarheel.  It generally works best with the 3-foot.  I have not checked the radiation patterns however.  It could be that a 5 foot stinger on this big inductor just skews the radiation angle way up or down.

I do know that MFJ does not make this screwdriver.  Give it a shot.  They'll take it back if you don't like it.
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N5EAT
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« Reply #4 on: January 29, 2008, 12:30:48 PM »

Another consideration is what size of antenna are you willing to put up?  The little screwdriver is extremely light and WILL give you loads of fun from 6 to 80 meters.

It's not a single band mobile dx machine however.  I have found that I have more fun with the ability to push a button and tune any band I wish with the little screwdriver.   The only other antenna I've liked better was my 3 stinger Hustler antenna.  It's fairly large and is not a babe magnet.  But it works very well.

Other than that, they are either too tall or heavy, or too limited in frequency coverage.  

For single band antennas, setting up the largest 20 or 40 meter you can without clipping bridges or light posts is a very good choice.
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