I know, I know... But I'm still confused.

[dragon_slayer79]

I'm wanting to purchase a new mobile antenna because my current one is really starting to show it's age and it just doesn't seem to be able to pull in as much as it used to. I'm currently using a RS 20-032 and have been for about 8-9 years now (the same one). I have been reading the forums for weeks now with others asking about antenna suggestions and it doesn't seem ANYONE can agree about anything. There HAS to be a difference in performance or something between a $20 all band antenna and a $100+ all band. If there's no, and I use the term loosely "BEST" antenna then why isn't everyone running a $20 paper weight?

The bands I listen to 90% of the time is 150-160 & 450-460. I am a HAM and I do listen to area repeaters from time to time, but not constantly. Those frequencies are 53.03-1285.5. For the HAM stuff 90% of that is in the 140's and 440's. I was thinking about the Spectra, but I've read both comments "it a perfect antenna" and "it's junk don't waste your money" and everything in between. I'm on a tight budget and don't want to blow $100 on an antenna that will be worse than what I already have or doesn't perform any better than a $30 one. I'm not really too worried about it having to be very low profile, an antenna on my vehicle doesn't bother me. Obviously the one I'm using is a mag mount, but have been considering using a NMO mount. (hole type). Does this mount offer any advantages over a mag mount as far as being able to pick up signal better since it will be grounded to the vehicle? Or other advantages besides not being knocked off by a tree branch or something.

Other info you probably will want to know...

Scanner: Uniden BCT15X
Antenna: RS 20-032
Cable: Stock cable with BNC that's pre-attached to the antenna
Vehicle: '92 Saturn SL1

Oh I do listen to 800MHz when I can. Not a huge deal though. In my home county there is only very few 800's so I don't mess with them too much at this time.

Any suggestions and/or links to products that you might be able to provide will be greatly appreciated. Thanks for your help and time.

 

[kilowa22]

If you get a dual band ham VHF/UHF antenna that is 1/2 wave gain VHF and 5/8 wave on UHF it will work fine for all bands. Since you are a ham you have the advantage of using a transmitter to measure the SWR of the antennas you could tune them to 150 and 450 MHz for the best reception. I have used Comet mobile antennas with great success over the years and they are medium priced. The most important item for your antenna is to have it match a 1:1 SWR near the frequencies you monitor most to get the best reception.
Comet SBB-2 and SBB-2NMO Mobile Antenna
Comet SBB-5 and SBB-5NMO Mobile Antenna

 

[reconrider8]

Larsen Tribander is great

 

[ka3jjz]

All of these recommendations are fine - but let's back up a moment to address some of the things dragon had mentioned;

a. No antenna can cover such a wide swath of frequencies (you mentioned 6 meters right up to 1.2 ghz) without having some inefficiencies in one band or another. Put another way, there's no way to get a consistent response in a mobile antenna across such a wide range. It's just not possible. There will likely be compromises on one band or another (likely more than one). The most obvious candidate would be 6 meters and below.

b. I would have my doubts about hearing much above 1ghz consistently in a mobile environment. Possible, yes, but very likely it will be quite choppy and noisy, unless you are line of sight to whatever it is you are trying to hear. There are several 1.2ghz repeaters (and even some Amateur TV repeaters) in this range, but do a little homework first - are there any such repeaters in your area, or in an area that you travel frequently? In a similar vein, is there much use of the VHF lo band or 6 meters in your area?

c. I use the Spectra on my car with a heavy duty trunk lip mount. My area is pretty urban, so any mobile antenna with gain is a candidate to overload my handheld (a 396, and sometimes I use an older 245). It has survived several ice storms, hurricanes, blizzards (including the Snowcalypse) without issue (I had to clean the ice and snow out of the spring this year, but that was about it...). The question you need to really ask yourself is 'what mobile antenna will work best in my envjronment'? Take any claim about any antenna being 'the best' with a grain of salt.

There are a number of mobile antenna reviews in our Scanner Antennas wiki, and even some comments from eHam are also linked there. Educate yourself and see what would be a fit for your area.

d. Some antennas require a ground (the Spectra does - and I was told this by an Austin engineer..) while others don't (some ham 2/440 antennas, such as my Diamond dual bander). Whatever you get, try to mount it as high as you can- and if a ground is needed, usually a good trunk lip or roof mount will need to bite right into the metal, and that will usually suffice.

73 Mike

 

[benbenrf]

That age old question: .. which antenna??

Antenna performance is partly (largely) about how well designed an antenna is for the task it is to be put to. Not all 1/4wave antenna's constructed for the same freq perform the same, not all 1/2wave antenna's constructed for the same freq perform the same, and, not all 5/8wave antenna's constructed for the same freq perform the same.

There are variations in like for like antennas from manufacturer to manufacturer, not only in respect of di-pole types, but also in respect of like-for-like directional types, which results in different user experiences been reported and different opinions been expressed.

Also, there are setup influences i.e. how an antenna is setup by the user that will impact it's performance e.g. 2 users with the same antenna from the same manufacturer will/can experience different performance results depending on how they setup their antenna – one user may mount the antenna in the centre of the roof of the car (providing a more-or-less equi-area ground plane around the antenna) while another user may take the same antenna and mount it to the bumper of their car (resulting in a distorted shaped ground plane, and therefore better performance in/from one direction over other directions) – this experience is very typical of mag and bumper mounted type antenna's of the same design type. So, does a hole-thru mount offer better performance than a mag mount? Yes and no: in theory it could (by way of providing a better grounded earth), but it would be impossible to say catorgoricaly it would unless all the other potential influences were assessed as well (influences like the exact position the antenna is thru-hole mounted to the car). However, in a real world listening enviroment I'd be inclined to think that the difference in listening experienced, and the performance of 2 like for like antenna's in a situation like this are going to be boarder line i.e. you would be able to measure the performance differences, but other than in boarder line/weak signal reception/transmission situations real world listenable performance differences are going to be another matter.

…... and we can go on discussing & debating this: one user may be listening to signals on a given frequency originating from a transmitter with certain Tx characteristics (e.g. signal strength, polarisation, radiation angle above the horizon …. etc etc ….) whereas another user using the same antenna (and perhaps even mounted identicaly to the first user) and listening to the same transmitter signal, but from a different bearing/distance which will result in them having a very different listening experience.


So what does this all come down to? It comes down to antenna performance opinions been expressed which are as varied as the circumstances in which the antenna's are put to use!

How much does one spend on an antenna, and just how closely is “retail price” related to performance?
My experience of typical consumer type mobile VHF/UHF antenna's is that the relationship between retail price & performance can be a poor (very poor) gauge of performance. Cost in the consumer sector/price range is first & foremost about manufacturing country & labour/material (costs) then, it is about design/rf performance e.g. in 2 like-for-like antennas the antenna example manufactured in the Far East will retail in the West for considerably less than the same example made in the West, but it's performance is not likely to be any worse (or better for that matter). If you are going to experience any difference between the 2 antenna's it's more likely to be in the quality of the materials used, and consistency in manufacturing quality from production run to production run i.e. chances are the Western manufactured antenna will last longer than the Far East antenna - because the materials used are going to be of better quality. This however, does not neccassirly equate to better rf performance.

One thing you can be pretty certain of Dragon_Slayer79: improvements in performance from one antenna to the next do not improve in proportion to their increase in retail cost - the law of deminishing returns is very much in play here. Take the attached photos here of my R&S HE309 antenna, an active broadband receive only antenna working from around 20Mhz – 1300Mhz. It retails for around a cool $7000 plus. I assure you it does not offer 70 x the performance of a good quality 100bucks mobile antenna, or 35 x the performance of a good quality 200bucks antenna. Nope, in fact for any given frequency it's comparable 1/4wave and 1/2wave di-pole performance (which is characteristic of most mobile antennas – and, yes, this antenna can be used as a mobile antenna if mounted to a suitable bracket - it is used in Iraq and Afghanistan as a mobile broad-band VHF/UHF monitoring & interception antenna) is at very best, no more than around 3 x - 4 x better, or around 9 to 12dBi better – and that is only because of the active circuits (contained in the grey tube).

R&S also make a passive version of this antenna, the HK309 (thinner but longer - usable as a mobile antenna), and there are 2 other comparable passive antenna's the HK014 and HK033 (although these last 2 are not practical as mobile antenna's - except mounted on ships). Both have similar bandwidth characteristics – and both retail for around a cool $3500 - $5000.

But, how do they compare with that most respected (and capable) of consumer type broad bandwidth scanner/listening antenna's – the Discone - the very best of which, in Mil-Spec, don't cost much more than $2k?

Well, across the whole bandwidth their measurable performance is probably better than most Discone examples, but you are going to get 80% - 90% the performance of these top-shelf passive antenna's from just about any good quality, properly made/designed Discone for - and heres the important part - around 25% - 30% the cost of the R&S antenna's!

Its this characteristic in respect of just about every scanning/listening scenario that folk have to make a judgment about when selecting an antenna i.e. do you want to, or is it worth, spending so much (extra) money for one of these types of antenna's, and what they can offer performance wise, but for which in “advantage” terms, in "real-world listening and monitoring scenario's", is going to be evident in no more than a fraction of a single percentage of your overall listening time?

Horses for courses – a question of individual values: some people spend their hard earned cash on flash motorbikes (Ducati 998R), some on flash cars (Ferrari 288GTO), both of which, given the crowdedness of roads today are unlikely to get you from A to B any quicker (or drier!) than a car or bike costing a fraction of what they cost.

So whats the best antenna?
It's the antenna which is best going to suit your needs given a good evaluation of the circumstances in which it is going to be put to use.

That is your best antenna.

 

[dragon_slayer79]

If you get a dual band ham VHF/UHF antenna that is 1/2 wave gain VHF and 5/8 wave on UHF it will work fine for all bands. Since you are a ham you have the advantage of using a transmitter to measure the SWR of the antennas you could tune them to 150 and 450 MHz for the best reception. I have used Comet mobile antennas with great success over the years and they are medium priced. The most important item for your antenna is to have it match a 1:1 SWR near the frequencies you monitor most to get the best reception.
Comet SBB-2 and SBB-2NMO Mobile Antenna
Comet SBB-5 and SBB-5NMO Mobile Antenna

Thanks for the suggestions. I'll look into those.

 

[dragon_slayer79]

Larsen Tribander is great

Thanks for the suggestion I'll check this out.

 

[dragon_slayer79]

All of these recommendations are fine - but let's back up a moment to address some of the things dragon had mentioned;

a. No antenna can cover such a wide swath of frequencies (you mentioned 6 meters right up to 1.2 ghz) without having some inefficiencies in one band or another. Put another way, there's no way to get a consistent response in a mobile antenna across such a wide range. It's just not possible. There will likely be compromises on one band or another (likely more than one). The most obvious candidate would be 6 meters and below.

b. I would have my doubts about hearing much above 1ghz consistently in a mobile environment. Possible, yes, but very likely it will be quite choppy and noisy, unless you are line of sight to whatever it is you are trying to hear. There are several 1.2ghz repeaters (and even some Amateur TV repeaters) in this range, but do a little homework first - are there any such repeaters in your area, or in an area that you travel frequently? In a similar vein, is there much use of the VHF lo band or 6 meters in your area?

c. I use the Spectra on my car with a heavy duty trunk lip mount. My area is pretty urban, so any mobile antenna with gain is a candidate to overload my handheld (a 396, and sometimes I use an older 245). It has survived several ice storms, hurricanes, blizzards (including the Snowcalypse) without issue (I had to clean the ice and snow out of the spring this year, but that was about it...). The question you need to really ask yourself is 'what mobile antenna will work best in my envjronment'? Take any claim about any antenna being 'the best' with a grain of salt.

There are a number of mobile antenna reviews in our Scanner Antennas wiki, and even some comments from eHam are also linked there. Educate yourself and see what would be a fit for your area.

d. Some antennas require a ground (the Spectra does - and I was told this by an Austin engineer..) while others don't (some ham 2/440 antennas, such as my Diamond dual bander). Whatever you get, try to mount it as high as you can- and if a ground is needed, usually a good trunk lip or roof mount will need to bite right into the metal, and that will usually suffice.

73 Mike

Thanks for taking the time to break things down like you have. This helps me make a better more informed decision. I live in a pretty rural area over 10 miles to the nearest repeaters so anything that is more "sensitive" for lack of a better term when it comes to antenna is a good thing in my case I believe. I don't have an excess of radio traffic around here like in a bigger city does. the biggest town in my area is around 25K for population and they still use very basic analog systems. Thanks again for your help and insight.

 

[dragon_slayer79]

That age old question: .. which antenna??

Thanks for taking the time to offer your thoughts. They were very helpful in giving me more to base my decision on for what will best work for what I'm wanting to put it to work for.

 

[Tweekerbob]

Dragon Slayer, a couple of things:

1. Do you transmit on the HAM bands or do you just listen in with your scanner?

2. Is the only VHF-LO you listen to HAM?

Since a mobile antenna that hears well on everything between 50-1300 MHz is not available, and 90% of your listening in done in the business/public safety bands, I would recommend a good commercial dual band antenna if you are not transmitting on the HAM bands. Most if not all, can utilize a mag mount and still perform just as well as a hole in the roof.

Here is the Larsen Amateur catalog. Look on page 4 and 5 and you will see a visual depiction of how different electrical designs perform. The "donut" you see is supposed to reflect an omni-directional pattern. The grid on the bottom is supposed to represent the ground that you and I live on. You'll notice a general pattern. As you move from 1/4 wave to 1/2 wave the pattern is squished just a little, meaning that just a little more energy is focused more towards the horizon and less towards the sky. This is where gain comes from; it's the focusing of the radiated energy into one or more desired directions (generally at or just above the horizon). 5/8 wave squishes the pattern even more towards the horizon and even more squished when you start stacking and phasing elements on top of each other.

People have varied opinions about antennas for myriad of reasons.

1. They don't know what they're doing and screwed something up, or just did a poor job on the install and performance of the system suffered.

2. People live in different areas with different terrain and likewise different antenna needs. Someone living in a basin surrounded by tall mountains (where the repeaters are) is going to have very different needs than someone living in the Great Plains.

3. They had unrealistic expectations. No antenna is magically going to pull in a signal that is too weak.

Again, focus on the bands you really want to listen to, I assume 150 and 450MHz. What I understand is that you're playing it smart...trying to stretch your dollar and doing your homework before making a purchase. But having said that, if you are on a budget, you WILL have to make a compromise. You will either buy an antenna that is "wide-band", compromising the reception of all bands at least a little. Or, you will get a good 150/450 antenna where in those bands the reception will be about as good as you can reasonably expect; however, the compromise is that you will have probably worse reception on the other bands you only rarely to occasionally listen to.

If you want the best reception on all of the bands you listen to, be prepared to compromise the integrity of your wallet. Don't go too far, your car'll end up lookin like this (courtesy of Hamsexy.com)

 

[dragon_slayer79]

Dragon Slayer, a couple of things:

1. Do you transmit on the HAM bands or do you just listen in with your scanner?

2. Is the only VHF-LO you listen to HAM?

Since a mobile antenna that hears well on everything between 50-1300 MHz is not available, and 90% of your listening in done in the business/public safety bands, I would recommend a good commercial dual band antenna if you are not transmitting on the HAM bands. Most if not all, can utilize a mag mount and still perform just as well as a hole in the roof.

Here is the Larsen Amateur catalog. Look on page 4 and 5 and you will see a visual depiction of how different electrical designs perform. The "donut" you see is supposed to reflect an omni-directional pattern. The grid on the bottom is supposed to represent the ground that you and I live on. You'll notice a general pattern. As you move from 1/4 wave to 1/2 wave the pattern is squished just a little, meaning that just a little more energy is focused more towards the horizon and less towards the sky. This is where gain comes from; it's the focusing of the radiated energy into one or more desired directions (generally at or just above the horizon). 5/8 wave squishes the pattern even more towards the horizon and even more squished when you start stacking and phasing elements on top of each other.

People have varied opinions about antennas for myriad of reasons.

1. They don't know what they're doing and screwed something up, or just did a poor job on the install and performance of the system suffered.

2. People live in different areas with different terrain and likewise different antenna needs. Someone living in a basin surrounded by tall mountains (where the repeaters are) is going to have very different needs than someone living in the Great Plains.

3. They had unrealistic expectations. No antenna is magically going to pull in a signal that is too weak.

Again, focus on the bands you really want to listen to, I assume 150 and 450MHz. What I understand is that you're playing it smart...trying to stretch your dollar and doing your homework before making a purchase. But having said that, if you are on a budget, you WILL have to make a compromise. You will either buy an antenna that is "wide-band", compromising the reception of all bands at least a little. Or, you will get a good 150/450 antenna where in those bands the reception will be about as good as you can reasonably expect; however, the compromise is that you will have probably worse reception on the other bands you only rarely to occasionally listen to.

If you want the best reception on all of the bands you listen to, be prepared to compromise the integrity of your wallet. Don't go too far, your car'll end up lookin like this (courtesy of Hamsexy.com)

Hi Tweekerbob,

Thanks for the photo! That was a really good laugh!

For this antenna I will only be using it for receiving. No transmitting. I have a separate antenna that I use for the mobile HAM rig.

Yes the VHF-Lo is HAM and It's not a huge deal if I lose it. It's not in my local area I only get to hear it while I'm on the road anyway.

You had mentioned that if I did want to listen to all the bands it was cost a lot. Can you offer a little more insight on this possibility? I don't have thousands to drop on Mil grade equipment but I'm also a firm believer of do it right the first time and you wont waste your time and money in the long run. So if it means waiting a little longer to save up some more money, I'm completely cool with that.

I live in Iowa (Knoxville area) so I'm not in the plains nor the mountains, I guess rolling hills would be the best description of the terrain.

Thanks for replying and providing that link. The information you have provided has been very helpful... Now I desire MORE! lol

Jeremiah

 

[JStemann]

I have both the larsen tri-band and the austin spectra. They are very close in performance in the 150 and 450 bands. The larsen gets a slight edge in the 800 mhz are while the spectra gets a definite edge in the 42mhz area. Now, I've not checked these in the actual ham bands, only public safety stuff. I looked at both with an antenna analyzer, the spectra wasn't very pretty on the low band ~42 mhz, but it did at least show some resonance. The larsen wouldn't do anything, the meter was maxed out in a bad way. From experience, you will hear stuff in the vhf-low area just not as much as you could.

A couple of other options to look at, comet sells a dual band antenna (CA-2x4SR) that has a wide bandwidth for ham and public safety freqs., it covers 140-160 and 435-465. They also sell a tri-band, that covers 6&2m and 70 cm. (SB-14).

I don't have any experience with 1.2ghz, so I don't know how any of these will do in that band. I "suspect" the larsen tri-band would do pretty good there.

For around $30, you could get the larsen tri-band. A NMO mag-mount can be bought for under $20. I think the going price for most of the comet antennas are $50-$70. Don't forget they will need a so-239 style mount as well.

Hope this helps,
jeff.

 

[dragon_slayer79]

I have both the larsen tri-band and the austin spectra. They are very close in performance in the 150 and 450 bands. The larsen gets a slight edge in the 800 mhz are while the spectra gets a definite edge in the 42mhz area. Now, I've not checked these in the actual ham bands, only public safety stuff. I looked at both with an antenna analyzer, the spectra wasn't very pretty on the low band ~42 mhz, but it did at least show some resonance. The larsen wouldn't do anything, the meter was maxed out in a bad way. From experience, you will hear stuff in the vhf-low area just not as much as you could.

A couple of other options to look at, comet sells a dual band antenna (CA-2x4SR) that has a wide bandwidth for ham and public safety freqs., it covers 140-160 and 435-465. They also sell a tri-band, that covers 6&2m and 70 cm. (SB-14).

I don't have any experience with 1.2ghz, so I don't know how any of these will do in that band. I "suspect" the larsen tri-band would do pretty good there.

For around $30, you could get the larsen tri-band. A NMO mag-mount can be bought for under $20. I think the going price for most of the comet antennas are $50-$70. Don't forget they will need a so-239 style mount as well.

Hope this helps,
jeff.

Hi Jeff, Thanks for the input. It's good to get your info on these. I'll looking into these antennas that you have suggested. Thanks again for your help.