Best Wideband Antenna (30-950 MHz) Money can buy?

blantonl

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As they say in the audio world, your equipment doesn't mean anything unless you have good speakers.

As they say in the radio world, your equipment doesn't mean anything unless you have a good antenna. With that said, what do you think is the best wideband antenna available on the market right now, for 30-950 MHz?

I'm not talking anything bespoke - I'm talking something that can be purchased by a hobbyist, but the cost, for all intents and purposes, doesn't matter.

Thoughts?
 

kb5udf

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If I could have only one antenna for everything from monitoring CB to 900mhz trunking, it would be a basic discone. I'm not sure there is any great performance variability between commonly available consumer models.
 

prcguy

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30 to 950MHz with a single antenna would be an extreme compromise in every way unless you want directional, then a big log periodic will perform well across that range. But it will be big and directional. And expensive unless you find a deal on a mil surplus unit.

Most antennas I've seen advertising that kind of range are Discones with a whip and the typical scanner DIscone can work ok from a little above 100MHz to about 500MHz then it degrades a lot in the 700/800/900MHz range due to upward pattern shift. The whip on top is usually tuned to 50MHz where it performs about as good as a 49MHz telescoping whip on a walki-talki, then it drops off like a cliff above and below 50MHz. In the big picture its grim at best but its what most of us are forced to use due to space, $$ or lack of knowledge on how to do better.

The way I see it is you own a big popular scanner/SWL website and associated companies. You should have the best monitoring setup on the planet for that reason if nothing else. In your case I would go for several to many real antennas, not toy antennas, somewhat broad band but lots of gain within their advertised frequency range, then combine them all with no amplification unless your going to feed multiple receivers.

I did this to some extent but don't use it much. But as an example of what I did here once is a military OE-254 Bicone that normally covers 30 to 88MHz but I replaced the elements with longer ones giving up some of the top end to get CB and 10m at the bottom end. This antenna works fantastic from CB through 6m and more with full size half wave dipole performance across the entire range.

Then I have a mil surplus Discone for the VHF air band, then a 4-bay dipole array from Sinclair for 2m through high 160MHz range, then a huge 225-400MHz gain type omni, then a big exposed dipole array from Antenna Specialists for 440-470MHz, then a gain type stick for 700/800MHz feeding a big diplexer. But most of the time I have all that disassembled with the various antennas feeding specific radios.

For you I would consider the same military surplus OE-254 for 30 through 88MHz (or a smaller military COM-201B) then transition to an actual VHF air band antenna, full band with a little gain. Then a large gain type, probably exposed dipole array for 136-174Mhz and you will have about 6dBd omni gain for a 4-bay array. Then a military 225-400MHz high gain omni. These are hard to come by but I have a spare one in storage that's 11ft long and a good 4 to 5dBd gain.

Then another exposed dipole array for 406 to 512MHz with about 6dBd gain. If you need coverage from 512 to 700Mhz there are various antennas that will cover that range. Then a big broad band high gain omni for 700 through 900MHz or a little past. Then combine them all with a custom pentaplexer or whatever is needed from Austin Antenna. I have several from them that almost cover the bands I just mentioned and they can produce a custom version for whatever ranges you would need. Or feed a custom multicoupler with separate band inputs.

With what I just described you would have a significant amount of gain right at the antenna and a good 4 to 6dB at the very least to 20dB or more gain than the best Discone or other single broad band scanner antenna available. You could never get the huge SNR using small antennas with amplifiers, you must start with gain at the antenna to get the SNR way up. That will make up for most any feedline loss and give huge SNR ratio at the receiver(s). Then a high level, probably two section custom multicoupler that has separate amps for the low and high frequency ranges at minimum and internal diplexers. I could build the multicoupler with parts here on hand.

Anyway, you deserve the best so why not get the best? If the wifee gives you grief, just tell here you deserve the best (like marrying her) so you are getting the best in antennas to complement her.
 

mmckenna

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If money isn't an issue, and you want that sort of coverage, Telewave makes some nice discone antennas that will fit the bill.

Specifically you may want to consider the Telewave ANT220K https://pronto-core-cdn.prontomarketing.com/185/wp-content/uploads/2016/07/TWDS-7125.pdf

I have the ANT280S at work, it is only "rated" for 118MHz to 3GHz https://pronto-core-cdn.prontomarketing.com/185/wp-content/uploads/2016/07/TWDS-7108.pdf

That antenna has been up at one of my sites for about 10 years now. It usually connected to an AOR2300 black box receiver that I use occasionally, but I've used it for a temporary transmitting antenna when I've needed it. No flimsy elements, built like the proverbial brick outhouse. I fully expect it to outlast me.
 

prcguy

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I've been curious about the big Telewave Discone but would want to see the radiation pattern before investing in one. A typical scanner Discone has a fairly consistent pattern from the low 100MHz range then somewhere around 400-500MHz the pattern shifts drastically upward. I find they are about 10dB down at 800Mhz due to the pattern shift compared to the 400MH range. If Telewave has found a way around that it would be great. The big Telewave Discone is also only 58" tall with a top hat proportional to the higher frequency ranges. I would want to know more about its low frequency performance below 50MHz.

If money isn't an issue, and you want that sort of coverage, Telewave makes some nice discone antennas that will fit the bill.

Specifically you may want to consider the Telewave ANT220K https://pronto-core-cdn.prontomarketing.com/185/wp-content/uploads/2016/07/TWDS-7125.pdf

I have the ANT280S at work, it is only "rated" for 118MHz to 3GHz https://pronto-core-cdn.prontomarketing.com/185/wp-content/uploads/2016/07/TWDS-7108.pdf

That antenna has been up at one of my sites for about 10 years now. It usually connected to an AOR2300 black box receiver that I use occasionally, but I've used it for a temporary transmitting antenna when I've needed it. No flimsy elements, built like the proverbial brick outhouse. I fully expect it to outlast me.
 

mmckenna

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I've been curious about the big Telewave Discone but would want to see the radiation pattern before investing in one. A typical scanner Discone has a fairly consistent pattern from the low 100MHz range then somewhere around 400-500MHz the pattern shifts drastically upward. I find they are about 10dB down at 800Mhz due to the pattern shift compared to the 400MH range. If Telewave has found a way around that it would be great. The big Telewave Discone is also only 58" tall with a top hat proportional to the higher frequency ranges. I would want to know more about its low frequency performance below 50MHz.
That would be a good question. I only ~really~ use mine on VHF High, some UHF and played with it a bit on an 800MHz. It does seem to work sufficiently on low band, at least hearing CHP. Although I do not have a dedicated low band antenna to compare it to. And the version I'm using is only designed down to 118MHz. I don't have much above 900MHz to listen to with it, so no way to really compare it above that. I'd like to know what's "under the hood" on it, but I don't want to try to remove the shield around the feed point.

My main reason for buying that specific antenna was that I needed something durable that was suitable for use on a building roof that is shared with others. I also wanted the ability to use it as a back up antenna for one of the VHF or 800MHz repeaters I have at the site. The site is shared with some cellular carriers, and their installers act like 800lb gorillas. Not uncommon to see them standing on top of other antennas and other stupid *%$@. So far, this antenna has lasted.
 

blantonl

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Back in February I spoke at length with the developer of this antenna. It's developed and engineered locally here in San Antonio, and minus the microwave and radar spectrum components of this antenna which I wouldn't need, I get could one of these built for high 5 figures for me.

I've seen it in person along with other innovations Southwest Research does (I've been to a few meetings out there), and they've got a best of breed in the world set of antenna engineers, some of which I know personally.

Maybe I should just drop some coin on one of these bad boys and it would probably last 30 years or more. I'm serious when I say I would not be opposed to dropping 100K on a *****ing ass antenna.

AF-369-DF-Antenna.jpg
 

Ubbe

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Telewave says: Vertical beamwidth (nom.) 110 degrees (varies with frequency)
There's no way to change how a discone operates, you can only make it optimized for different frequency bands by scaling up or down.

Easiest solution would be a standard discone for 100-500Mhz and then another discone, that can be a standard discone that you cut all elements down to 1/4 size and use for 700-900MHz and connect the two using a diplexer that splits somewhere at 600MHz.

To cover 25-50Mhz you will need some sort of mil antenna and use that with a low pass filter at 70MHz and connect to the receive coax. The low band discone would hopefully not interfere much or you will have to use a high pass filter from that discone.

If there are specific more narrow band frequencies that you would like to concentrate on then a gain vertical antenna for those bands would be the best and then use filters for each one of the antennas. You could use an amplifier at each antenna to match it better to frequencies outside of its range and to overcome any filter losses and also coax losses.

/Ubbe
 

prcguy

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I've had a couple of antennas from Southwest Research and still have one left, I posted about it years ago here: Surplus SRI Discone info

Yes they can make very broad band antennas. No they won't have any gain to speak of. A system as I described before combining separate high gain single band but broad band antennas would work much better than any single $100k antenna that SRI could come up with.

Back in February I spoke at length with the developer of this antenna. It's developed and engineered locally here in San Antonio, and minus the microwave and radar spectrum components of this antenna which I wouldn't need, I get could one of these built for high 5 figures for me.

I've seen it in person along with other innovations Southwest Research does (I've been to a few meetings out there), and they've got a best of breed in the world set of antenna engineers, some of which I know personally.

Maybe I should just drop some coin on one of these bad boys and it would probably last 30 years or more. I'm serious when I say I would not be opposed to dropping 100K on a *****ing ass antenna.

View attachment 89910
 

popnokick

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The AF-369 Terrestrial DF Antenna has a bunch of electronics included that you don't need.... or want... in a scanner antenna. It is a specialized system for direction finding using DTOA (Differential Time of Arrival) and phase differences to determine more precise headings than you get with the much less expensive "null" seekers used by most hams for fox hunts. It is the professional version of the DF2020T direction finder (shown here GLOBAL TSCM GROUP, INC. - Radio DF DDF2020T )
 
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