Is anyone happy with the Austin Spectra Amateur Four Band Mobile?

[jon_k]

Here is the review page:
http://www.eham.net/reviews/detail/5618

The two reveiws are supportive. I just purchased this with "mirror mounting" gear so I can psychically attach to the side of my truck toolbox. This will be my first antenna apart from the stock rubber ducky that came with my mobile scanner. I'd like to hear a weigh-in from anyone who has used this, or if you know anyone who has, and what your remarks are about performence. Any feedback regarding this purchase is welcome.

 

[ka3jjz]

I've had mine for quite a while now, and for public service freqs (and strangely enough, it works OK on the civil air freqs, too), it's quite good. Make sure you have a good ground; this antenna needs it.

For example, I could hear - albeit noisely - my home 800 Mhz trunked system from 40 miles away. On a mobile, without the advantage of height, that's about as good as you're going to get.
73 Mike

 

[jon_k]

I've had mine for quite a while now, and for public service freqs (and strangely enough, it works OK on the civil air freqs, too), it's quite good. Make sure you have a good ground; this antenna needs it.

Glad to hear someone is satisfied!

One question of your post. (Still trying to learn antenna design.) By "good ground" you mean ground plane? Correct? I don't think you mean an electrical ground. (I'm assuming the radio itself provides whatever electrical ground the antenna circuit itself needs.)

I always get "electrical ground" and "ground plane" confused when you folks say "needs a good ground". I'm more familiar with electrical circuits/electrical grounds and "ground plane" is a new concept to me altogether! I'm sure this will become more obvious when I install my first antenna.

P.S. Hopefully this will be a good starter antenna for Amateur radio broadcast (on 50-144,440) as I do have intentions to get licensed sometime in the future. It'd be nice to be able to have multi-use equipment.

 

[windchaser]

i have two of them and thay work great out in the country, i have tried others but thay dont come close to what i have. i am sold on them. A+ windchaser usmm ret

 

[ka3jjz]

Yep, it will hear those ham freqs, no sweat. We don't have many 6 meter repeaters in our area, so it's hard to judge - but I've heard 450 mhz tropo from NJ with this antenna when conditions are good.

A very simple way to test whether you have a good ground on the mount and antenna is to use any old cheap Volt Ohm Meter (VOM). Put one end at the base of the mount, the other to a good firm point bolted to the frame (such as the bolts that hold the front seat to the floor). You should get a full (or nearly so) deflection on the meter.

Simple and effective for this application. By the way, an Austin engineer told me about the antenna needing a decent ground to work properly - so it's not just me!

73 Mike

 

[af5rn]

In other words, it's not worth a fark on a mag mount. I can attest to that from experience.

So man up and drill that hole!

Oh, and read each and every piece of paper included with the antenna VERY CAREFULLY before you start jacking with it, or you will screw it up, guaranteed.

 

[jon_k]

In other words, it's not worth a fark on a mag mount. I can attest to that from experience.

So man up and drill that hole!

Sure thing! I purchased a "mirror mount" which is an L bracket with two screw mounts. I assume the L bracket will conduct ground for the ground plane. I choose that so I could mount the antenna on the SIDE of my truckbed toolbox. I would prefer the side, as I don't want an antenna on top to interfere with opening the toolbox. (And to af5rn's disgust I'll say that 2 small screwholes are better then 1 large hole :lol: .)

If the performance is bad (I hope not. It's a metal L bracket after all) then I'll definitely buy a hole mount and drill a hole in the toolbox. The downside is I'll have to unscrew the antenna everytime I open the box. The way it opens, an antenna there would smack against the back of the cab. Luckily the toolbox isn't a highly used item.

Oh, and read each and every piece of paper included with the antenna VERY CAREFULLY before you start jacking with it, or you will screw it up, guaranteed.

Thanks for the forewarn. I'm one of those who like to jump into things and plug it in and troubleshoot as I go. I'll read the papers that come with it.

 

[ka3jjz]

Well at one point I was using a Diamond heavy duty mag mount with the antenna and it worked pretty well for me. (Some kid who couldn't get the mount off cut through the coax and stole the mount - probably for a lark...grrrr...). I'm in an urban area.

I suspect that at least some folks who say the antenna didn't work for them didn't consider the possibility of desense due to overload, which is a problem for some modern scanners, or did not know the antenna had to have a good ground. But I agree with AF5RN - man up and drill the hole in the cab. You'll be absolutely sure you get a good ground out of that.

73 Mike

 

[N1BHH]

Here is the Larsen mirror mount: http://www.universal-radio.com/catalog/hamantm/1474.html
I believe the mount you have is the Larsen TMB or similar, which is really used for mounting an antenna to the inside of the trunk or hood lip, or similar to this: http://www.hol4g.com/ac/product.aspx?number=LAR-TMB-38B&p=173381&sc=0

 

[jon_k]

Here is the Larsen mirror mount: http://www.universal-radio.com/catalog/hamantm/1474.html
I believe the mount you have is the Larsen TMB or similar, which is really used for mounting an antenna to the inside of the trunk or hood lip, or similar to this: http://www.hol4g.com/ac/product.aspx?number=LAR-TMB-38B&p=173381&sc=0

I actually purchased this mount:
http://www.scannermaster.com/NMO_Mirror_Mount_p/13-540567.htm

I'm not sure how good this mount will be applicable to mounting on side of the toolbox, but it will get me up and running if nothing else. I also had to purchase a PL-259 to BNC converter. I'm unsure how this will effect my signal with the extra fitting, and I may need to modify the wire to accept BNC at some point. In the future I may bite the bullet and drill holes in my roof.

I'll see how it works. Hopefully it will be better my rubber ducky in-car. I'm feeling like the Spectra was a good place to start as nobody has any complaints.

 

[af5rn]

Well, I hate to break it to you, but that mount takes four screws, not two. :lol:

It's very similar to the L-bracket, but there is a vertical groove down the centre of it to surround a mirror post. You'll just discard the back piece that goes on the back of the mirror. It should work just at well as an L-bracket, if not better, but yeah, it's going to take four screw holes, not two. The Austin is a very heavy antenna, and it needs all the support you can give it.

Again, I warn you, do not even try to screw the antenna to the NMO until you have read ALL of the paperwork. A lot of people screw up their brand new Austin by not reading the fine print. There are slow, tedious adjustments that MUST be made to the antenna base before you attempt to screw it down, so be careful!

Anyhow, I thought you had a side-opening tool box. Apparently yours is the kind with the single hinge opening top instead of the double end lids? Yeah, that complicates it, lol.

 

[silvery37]

What is a good way to get a ground if I use the antenna at home?

 

[af5rn]

What is a good way to get a ground if I use the antenna at home?

Search "ground" in this forum instead of hijacking an unrelated topic.

 

[n4yek]

Search "ground" in this forum instead of hijacking an unrelated topic.

He's not hijacking, read the question.

What is a good way to get a ground if I use the antenna at home?

There is a pole to attach the antenna to if you plan to use it as a base station antenna.
Here is a link that shows it:
http://www.rfwiz.com/AustinAntenna/AustinAntennaSpectra.htm
It's not cheap though, it cost just as much as the antenna.

 

[ka3jjz]

A far less expensive way to go would be to get a good quality mag mount (I used the heavy duty Diamond model) and let it sit on something that's metallic to form the ground plane. Air conditioning units are almost ideal as there's lots of metal...

73 Mike

 

[silvery37]

Thanks for the help. I am very new to this. I found out what a ground plane is. I bought the austin spectra and a larsen magnet mount. My kitchen table has a stainless steel surface so that should work well as a ground plane.

 

[af5rn]

Thanks for the help. I am very new to this. I found out what a ground plane is. I bought the austin spectra and a larsen magnet mount. My kitchen table has a stainless steel surface so that should work well as a ground plane.

My apologies for my previous post. N4YEK is right, I misread your question.

As for good results with a Spectra, I hear a lot of people rave about them, but I'd like to know exactly which bands and distances they are listening to. I am beyond disappointed with the performance on UHF and 800mhz, even in suburban proximity. VHF is good. Unless you listen to low band a lot, the Spectra just isn't worth it, as far as I am concerned. Using a mag mount, it works no better than a good duck.

 

[ka3jjz]

It's interesting - my experiences on UHF/800 are exactly the opposite. It performs superbly - see my notes earlier in this thread. Heck, I shouldn't be able to hear the 450 mhz public safety freqs from BWI airport when I'm 20-25 mins away in Woodlawn, but I do, albeit somewhat noisely. With that much distance and hilly terrain, plus a semi urban enviornment, I doubt I could ask for more 73 Mike

 

[af5rn]

Ya know, the more reviews and opinions I read about the Spectra, the more I wonder if they don't have a weird problem with quality inconsistency. People seem to either love them or hate them, with little middle ground. I realise that a lot of people ruin the antenna during the mounting process, before they ever even attach it to their radio, accounting for a lot of the negatives. But there are plenty of others who do it all right and still get poor results.

Attached to a Larsen mag mount on a car boot, an air conditioner unit, and an 18 inch steel box, I consistently get 800 performance that is not noticeably better than with an 800mhz duck. Not even a full bar of signal difference.

I'm almost tempted to order another one and compare, just to be fair. But then again, I really have no use for an antenna that big, heavy, ugly, and unstable. My current one is now in my attic as a back-up.

 

[n4yek]

Ya know, the more reviews and opinions I read about the Spectra, the more I wonder if they don't have a weird problem with quality inconsistency. People seem to either love them or hate them, with little middle ground....

I know what you mean, I have been wondering if I should get one of these or not.