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Ive actually thought about getting one of thes ALS-500 I like my other Ameritrons and have had a few of these ALS-500 come my way for pretty good prices and I often feel like wrappin myself in the head for not grabbing one

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""""was not thinking of a cber sat with his makita screwdriver winding round the presets untill his meter said s9+60db from a guy on a handheld 15 miles away""""

Surely you'd prefer to have a Metron in the trunk?

So much neater back in the 80's. Who needs all that untidy wiring anyway.

Here's one of my two. I still have one brand new in it's 20year+ old box.



Unit 148

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'A man's got to understand the limitations of his test gear'

Harry Callahan

That's good to know. I have swap meet knock-off hamsticks that are only rated for 200 watts.

I passed on one of those a few years ago at a hamfest that was in real nice condition. I probably should have purchased it, but he wanted a bit much. Actually, he wanted more than a brand new ALS-500. There is something to be said, however about being able to get tech support for a product because the company is still in business.

You must be a mind reader... that's exactly what I replaced it with. I bought an IC-706IIG and hated it in comparison to the FT-100D so I put it on ebay and got a NEW-IN-BOX Metron for it.

Got 775w pep from the Metron.

Harmonics and Intermod Products

No linear amplifier review is really complete without some discussion on the the harmonics and intermod products introduced by the amplifier. I don't personally have the equipment to measure this, but I have consolidated some information on the subject published by G3SJX.

The following table shows both 2nd and 3rd Harmonic output levels, as well as Intermod products using a 2-tone SSB test. These test numbers are for an amplifier output level of 400 watts max. Note that 21Mhz is missing intermod metrics because he was not able to achieve 400 watts of output on that band with his test amplifier.

FREQUENCY	2nd Harmonic	3rd Harmonic	3rd Order I-mod	5th Order I-mod
1.8 MHz	-52dB	-56dB	-30dB	-50dB
3.5 MHz	-51dB	-57dB	-30dB	-47dB
7 MHz	-65dB	-55dB	-28dB	-48dB
10 MHz	<-70dB	-62dB	-28dB	-42dB
14 MHz	<-70dB	<-70dB	-24dB	-42dB
18 MHz	<-70dB	-66dB	-24dB	-42dB
21 MHz	<-70dB	-68dB	n/a	n/a
24 MHz	<-70dB	<-70dB	-25dB	-40dB
28 MHz	<-70dB	<-70dB	-24dB	-42dB

Summary

I've had this amplifier in my Jeep Wrangler for several years now and it has been reliable. The SWR and band protection circuits really do work well, but it requires that you have a pretty carefully tuned mobile antenna system. In my case, I had to tweak my matching system for 80 meters to make everything happy.

In my Jeep, I've done practically every type of off-roading, from mountain trails, to rock crawling, and bouncing around in the desert. Everything gets rattled around and shaken. Despite all of this, the amplifier has held up and I've had no component breakage. The only part I've ever replaced was the remote meter panel because it yellowed over time from the sun. The replacement was done merely for cosmetic purposes; it was working fine.

I did have one problem that developed where the amp would key, but not draw any current and not produce any power output. This problem turned out to be caused by a faulty remote head cable (cheap CAT 5) that needed to be replaced. I guess over time one or more pins in the RJ45 on the cable had developed an intermittent connection. Replacing it with a better quality, more durable cable solved the problem.

So in summary, the ALS-500M amplifier has proven to be durable enough to be used in a rugged environment. The power output is as advertised, although the numbers drop off a little on the higher bands. The remote head is small enough that you can trunk mount the amplifier and it has all the features needed to help keep you from blowing it up . The 3rd order intermod performance is adequate for mobile use, but you might want to consider a different amplifier to use in a base installation.

As a whole, I'm pretty happy with this amplifier especially considering the space I am constrained with.

I think some of you guys must have mental health issues. Why on earth would you compare a product designed and marketed to Ham radio operators. I mean seriously why would you make such a illogical and poorly conceived argument for an item by comparing it to an illegal product not designed for Ham's? I understand what an inferiority complex is and have to wounder why you guys feel so inadequate that you have to make such silly comparisons. Maybe we can compare a Ham gear to commercial and military broadcast gear that would be just as pointless, illogical and ill conceived. Traditionally Loser and Bullies compare themselves to other's that they know are clearly not on par with themselves this makes them feel all good warm and fuzzy inside about themselves as they collectively pat each other on the back!Real men compare themselves to those that are better then they are so they have something to aspire to something to drive them to greatness!

Personally I would ashamed of myself collectively as a group if all I did was whine about people I think are bellow me and sat around pointing out how great I am and how great the gear I buy is!!!LOL

You are supposed to set an example for those that are bellow you to aspire to I do not want to be like anyone that has to get a collective group hug by putting other people and products down in order to feel good about themselves or to justify any purchase they may make.

I think it is stupid to put 100 watt's into a design to get 300-450 watt's back out. All the stuff that is in this design that is not on a Texas Star 667 or 500 could be added easily. Some of it is not even needed and is of dubious good to begin with.The basic RF deck is not anything significantly new. WOW 4 BIPOLAR 2sc2879'S what a clever idea I wonder why no one else thought of that....Oh yeah that is right that idea has been in the CB world for over 2o year how nice for Ameritron to make it late to dinner! For what they charge for the product it should be auto-tuned and work on 120V and 12V. Plus it is huge you could fit 2 TS667's in the same space it takes up. So it had better have a lot more parts in it for it's size. I am guessing I could by a 16 transistor Texas Star for what thing must cost. Since unlike most Ham I can actually use a soldering iron and can read and understand the ARRL Handbook I could add most of this to any decent solid state amp on the market.

On top of that most of the reviews I have read on eHamreviews has been very negative about this product. Ameritron as usual has had quality control issue's and less then spectacular customer service. Many of them are not putting out the power they should either. DO not take my word for it go read all the reviews.Best part is that Texas Star does not use any surface ount parts so I can work on them. If you look at the 10/12m tuning circuit notice the cap is SMD to a small silver coil. Their are other smd's in this unit too which means should it break during a National or Local Emergency you will not be able to fix it on your own more then likely.

I do not though think the power input required to get such meager output is worth it not at the dollar per watt output. You could take an auto-tuner board insert it in a 4,5,6,8,12,16 transistor Texas Star and have a very similar end product with more output for every watt input if you remove the swamping circuit from them.

I still hold that if you want to compare Ham gear you need to compare it to the best out their so broadcast gear and military gear not illegal gear designed for price point sales to those that know little to nothing about RF circuits. Aspire to greatness not to be petty thugs!

One reply I have is that it's really not just as simple as adding band-selectable filters (which is what I assume you meant by "auto-tuner board"). While I'm an advocate of doing exactly what you suggest, having built a couple sets of filters to use with CB-style amps, it doesn't equate to the same quality of design that even Ameritron amps demonstrate. One major difference is in the biasing. Texas-star uses a brute-force biasing method that utilizes a clamping diode and a big resistor to deliver voltage and current to the transistor's bases. While it does work up to about the 100W level with acceptable results, this method has some major drawbacks in that the bias voltage sags on signal peaks, causing the amp to fall back into class C territory. This method is also sensitive to variations in supply voltage, so if the voltage source feeding the amp drops below 13.8V the bias voltage drops also. What is needed is regulated bias, where a voltage regulator is used to provide constant bias voltage to the tranistors. Also, Texas Star doesn't include temperature tracking of the bias, which is important to help avoid thermal runaway during operation.

Also, the feedback networks in the Ameritron design are superior to the capacitor/resistor feedback loop used by Texas Star and most other CB amp manufacturers as they include an inductive element in the form of a transformer that samples the output for return to the input and helps level the gain of the amp across it's full range.

There are also much better designs out there than Ameritron, but not from any CB amp manufacturer I know of, at least none without some serious modifications.