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Author Topic: Diamond BB2M Multiband hf antenna  (Read 5628 times)
M3RLQ
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Posts: 15




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« on: October 01, 2013, 07:48:40 AM »

Has anyone even heard of this antenna in the states as I have seem no reviews of this antenna's performance. I'm from England where this antenna is widely available, costs around £270 - $440 but not sure wheater to part with my cash if there is nothing good to say about this antenna.

Would appreciate some feedback guys.

Regards
M3RLQ
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K5LXP
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« Reply #1 on: October 02, 2013, 06:44:10 AM »

My personal opinion would be any antenna that has less than 2:1 SWR over that frequency range is a dissipator and not a radiator.  For that kind of money you could get a much more efficient setup.  In a situation like mobile operating where a percent or two greater efficiency matters, the no-tune convenience is offset by the frustration of operating QRP ERP.

Mark K5LXP
Albuquerque, NM
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M3RLQ
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« Reply #2 on: October 02, 2013, 07:24:38 AM »

Well with that said, I can only work QRP as defined by my licensing condiction.

Thanks for your reply.
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K5LXP
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« Reply #3 on: October 02, 2013, 08:54:31 PM »

You wouldn't be QRP, you'd be QRPp with only 10W input to an antenna like this.  Even with an efficient antenna it'd be a challenge.  On higher bands your odds would be better but I wouldn't spend $400 to find out.  I'd build or buy a single band antenna and try it out that way.

I have a similarly inefficient HF mobile antenna, a Yaesu ATAS.  Even at 100W input it's a challenge to be heard when competing with other stations running any kind of power or decent antenna.  "Mobile station try again" is something you get used to hearing when running crappy antennas.

Mark K5LXP
Albuquerque, NM
« Last Edit: October 02, 2013, 09:08:03 PM by K5LXP » Logged
M3RLQ
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Posts: 15




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« Reply #4 on: October 03, 2013, 02:12:00 AM »

Well I don't have that luxury of putting up wire antennas dipoles and so on as I live in a ground floor apartment.
Have worked the world QRPp from an old address with the conditions permitted. Admittedly the skip is crap right now so time to investigate in an alternative antenna for my predicament!
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WX7G
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« Reply #5 on: October 03, 2013, 02:35:01 AM »

http://www.elix.cz/sites/elix.cz/files/BB2M.pdf

The Diamond BB2M is broadbanded by making it lossy. Quoting the Operating Intructions:

'Due to its broadband structure, in some case propagation
efficiency of the antenna may be reduced to 1/10
compared with conventional resonant type antennas."

With "conventional resonant type antennas" of this size having a radiation efficiency of perhaps 10% at 7 MHz, the BB2M is admitted to have a radiation efficiency of 1%.

Dave's (that's me) Rules of Small Antennas:

Small
Efficient
Broadband

Pick any two


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M3RLQ
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Posts: 15




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« Reply #6 on: October 03, 2013, 03:02:02 AM »

Thanks Dave,

I already have this information on the BB2M, but that's about it! No reviews would suggest it's not a sort after antenna especially over their in the states. But like I said my setup conditions are very much different from most and very limited due to my locality. I guess ground wave is as good as it's going to get!
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K5LXP
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« Reply #7 on: October 03, 2013, 06:16:49 AM »

You're approaching this from the wrong direction.  Rather than pick the least efficient antenna for your situation, you need to focus on the most efficient antenna you can get.  I understand - apartment, ground floor, foundation license.  The deck is stacked against you right out of the chute.  So then why use a 1% efficient antenna on top of it?  As WX7G points out an efficient antenna that size could be 10% efficient.  Not great but it puts you in the mobile antenna efficiency range which has a chance of working.  At least shoot for that while exploring other options that could be even better.

Mark K5LXP
Albuquerque, NM
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M3RLQ
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Posts: 15




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« Reply #8 on: October 03, 2013, 10:45:29 AM »

So no positive reviews, I'll close this topic!

Thanks to one and all.
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