Betso Bowtie versus 1/2 wave wideband whip

[Indeliblesound]

I’m not an expert on this topic, and I see a lot of props for Betso Bowties so this is in no way trying to undercut those who use them successfully. But can someone explain to me in layman the difference? I’m sure there are high level variations, but the details as it would apply to real life performance. 
 

If the bowties are in essense multiple omni dipoles in a compact configuration how would that differ greatly from a 1/2 wave wideband whip antenna? Both are omni, both can cover our usable frequencies, etc. 

 

Any feedback from experts appreciated?

[humbuk]

The length of the whip antenna determines the frequency at which it is best suited. The Bowtie Betso is tuned to 470-700MHz and also has a filter above 700MHz.

[Indeliblesound]

I was referring to the wideband whips you see more in HAM/amateur radio applications and tune to 400-900mhz. But giving this second though maybe the antenna is optimized for middle of that range?

[PMC]

There is the simple fact that getting the passive antennas, Betso, shark fins, etc. up and away from your mixer bag offers a bit clearer reception. It isn't demonstrable but it is a bit better.

[borjam]

On 3/9/2024 at 5:29 PM, Indeliblesound said:

I was referring to the wideband whips you see more in HAM/amateur radio applications and tune to 400-900mhz. But giving this second though maybe the antenna is optimized for middle of that range?

 

Amateur radio antennas are not usually wide band. Some are multi band as in “supporting  several narrow bands” which is radically different.

 

So you can find antennas that work on 144 - 146 MHz and 430 - 440 MHz but for, say 300 MHz they won´t be well matched.

 

For example, at embassies and military installations you can see huge log periodic antennas (the equivalent of the shark fin) while hams use multi band Yagis. For an amateur the wide band antenna covering, say, 3 - 30 MHz is overkill when you really need to cover narrow segments at around 3.5, 5, 7, 10, 12, 14, 18, 21, 24 and 28 MHz. The bands of interest are on average 200 KHz wide (except the 28 MHz band, 1.7 MHz) .

 

Edited March 11 by borjam
Somehow missed half of the post when writing.

[ramallo]

4 hours ago, Indeliblesound said:

I’m not an expert on this topic, and I see a lot of props for Betso Bowties so this is in no way trying to undercut those who use them successfully. But can someone explain to me in layman the difference? I’m sure there are high level variations, but the details as it would apply to real life performance. 
 

If the bowties are in essense multiple omni dipoles in a compact configuration how would that differ greatly from a 1/2 wave wideband whip antenna? Both are omni, both can cover our usable frequencies, etc. 

 

Any feedback from experts appreciated?

Look in technical characteristics the gain, less than a 1/2 dipole

[borjam]

2 hours ago, ramallo said:

Look in technical characteristics the gain, less than a 1/2 dipole

Yes but better tuned. And if you can place it so that stuff is outside the near field it will work better.

[JonG]

The main advantage of using something like a Bowtie vs. a 1/2 wave dipole would likely just be more surface area on the Bowtie. But like it has been stated, getting your antenna up and out of the bag would likely be more effective. 

[ramallo]

12 hours ago, borjam said:

Yes but better tuned. And if you can place it so that stuff is outside the near field it will work better.

I guess it depends on whether the 1/2 dipole is at its correct distance. The advantage that I see in the Botwie is that it is suitable for multiple frequencies at the same time and you forget about it, but at the cost of losing gain. But also according to those at Betso it has an SWR of 1.2:1 (I think it is too good ) against the 2:1 (Fair) of, for example, the Lectrosonic SNA600a. Much more efficient the Betso

[LarryF]

1 hour ago, ramallo said:

I guess it depends on whether the 1/2 dipole is at its correct distance. The advantage that I see in the Botwie is that it is suitable for multiple frequencies at the same time and you forget about it, but at the cost of losing gain. But also according to those at Betso it has an SWR of 1.2:1 (I think it is too good ) against the 2:1 (Fair) of, for example, the Lectrosonic SNA600a. Much more efficient the Betso

The SNA600a is 2:1 only at the band edges. When defining bandwidth, the 2:1 value is a commonly accepted bandwidth definer. Inside that bandwidth, the SNA600a SWR is much lower on the order of 1.2:1. Keep in mind, a tunable bandwidth may be useful in attenuating undesired RF.  "Different horses for different courses" .

Best Regards,

Larry Fisher 

[ramallo]

23 hours ago, LarryF said:

The SNA600a is 2:1 only at the band edges. When defining bandwidth, the 2:1 value is a commonly accepted bandwidth definer. Inside that bandwidth, the SNA600a SWR is much lower on the order of 1.2:1. Keep in mind, a tunable bandwidth may be useful in attenuating undesired RF.  "Different horses for different courses" .

Best Regards,

Larry Fisher 

Good to know Larry, I took the data from your website, I think it would also be good to have the SWR information at its best (As Betso's should be)

 

Thank you

[Indeliblesound]

Thanks for the feedback everyone.

 

I couldn't find an example of the wideband dipoles I was pointing out, but here's something somewhat similar - while using our trade specific retailer:

https://www.gothamsound.com/product/half-wave-dipole-antenna

 

Or this one which is apparently spec'd to go from 450-960mhz?

https://www.sennheiser.com/en-gb/catalog/products/wireless-systems/rf-accessories-2580z/em-2050-uhf-antenna-577785

 

I can see how the first is similar to a Lectro whip A1(B19) or B1(B22) but what about the latter?

 

 

[borjam]

On 3/10/2024 at 12:40 PM, ramallo said:

I guess it depends on whether the 1/2 dipole is at its correct distance. The advantage that I see in the Botwie is that it is suitable for multiple frequencies at the same time and you forget about it, but at the cost of losing gain. But also according to those at Betso it has an SWR of 1.2:1 (I think it is too good ) against the 2:1 (Fair) of, for example, the Lectrosonic SNA600a. Much more efficient the Betso

 

You are right about the distance: A misunderstanding on my part. When comparing a half wave dipole to a wideband bowtie antenna I assumed the half wave dipole was a builtin antenna in a receiver. My silly mistake

 

By the way, the Lectrosonics SNA600a with its thick elements is a kind of a wideband antenna. A similar trick to the Nadenenko dipole you could see on many trawlers.

 

That said: antennas can get detuned by stuff placed inside the near field (roughly 1 wavelength) and I wonder whether a wide band botwie can be a bit more "lenient" in that aspect. If someone can lend me one I can give it a try with the VNA

 

(By the way I edited my previous post about amateurs using multi-narrow-band antennas instead of wide band ones). For some reason it got eaten (or I hit send before finishing it).

[Fred Salles]

Is there actually such a thing as « 1/2 wave wideband whip »  ? 
It does not sound right since by definition 1/2 wave applies to one dipole for a given center frequency and most wideband antennas are (to put it simply) made from several dipoles with various center frequencies to be able to cover a wider range. That is the case for the bowtie and all sharkfins antennas that I know. hence the lower gain compare to a single dipole. 
A whip antenna is a monopole with a ground plane within the receiver to « make it behave » like a dipole. It then has a single center frequency and the range is limited around it. 
 

@Borjam I do not see the Lectrosonics SNA600a As a wide band. unless I misunderstood, it is a dipole with an ajustable center frequency. So it allows to use it with a « wide range » of receivers but once set it is limited to the band around the chosen frequency, like a normal dipole. 

[borjam]

2 hours ago, Fred Salles said:

@Borjam I do not see the 

Lectrosonics SNA600a As a wide band. unless I misunderstood, it is a dipole with an ajustable center frequency. So it allows to use it with a « wide range » of receivers but once set it is limited to the band around the chosen frequency, like a normal dipole.

 

It's a really clever design, the dipole arms are wide which increases bandwidth. Wider than a typical dipole anyway. I think Larry explained it somewhere.

[agarrison]

Nice description of various types of Antennas and their function/use by Nicholas Field in this YouTube video. https://www.youtube.com/watch?v=MD2PuIZixjA