Ameritron ALS-500M HF Solid State Amplifier Review

[eagle1911]

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.

 

[bob85]

, I am guessing I could by a 16 transistor Texas Star for what thing must cost

, 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.

and can read and understand the ARRL Handbook I could add most of this to any decent solid state amp on the market.

you guessed wrong,
texas star are far from been a decent hf amp
you won't have a very similar product without extensive reworking of the cb amp,
what you end up with as eagle explained is a cb amp with feedback networks that do nothing to flatten the gain curve, redneck bias circuits that cannot do whats needed, transformers that don't like lower frequencies, no vswr or overdrive protection, impedance excursions that need correcting or swamping, an amp that your average vehicle electrical system cannot cope with and an autotuner that won't fit inside the box,

, Since unlike most Ham I can actually use a soldering iron

thats great news

.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

not great news,
please make up your mind, you either CAN use a soldering iron which includes been able to work on the large and relatively easy to work on smd parts or you CAN'T,
even small surface mount is not that difficult if you can use a soldering iron

, I do not though think the power input required to get such meager output is worth it not at the dollar per watt output.

regulations rule commercial ham products but you could reduce the input swamping to get more watts for every input watt if you like, oh sorry you said that already about texas stars which have little to no swamping lmao,

, 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!

, and have to wounder why you guys feel so inadequate that you have to make such silly comparisons

WHO that knows little about rf circuits is making silly comparisons to inferior texs star cb amps?
if you know anything about solid state amps you also know its beyond an average ham or cber to modify such an amp for propper hf use yet YOU feel the need to inform everybody in a most undiplomatic way how inferior they are and how YOU could do it with an autotuner lmfao,

, Personally I would ashamed of myself

you should be, you sail a fine line between petty internet thug and self back patting idiot, recognising you have issues is the first step towards getting help with your mental health problem,

, 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

i bet you do, your shrink probably explained it in his diagnosis.


you sound like scott:sad:

 

[Moleculo]

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 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

Where in this review was the amplifier compared to any CB amp? Let me answer that for you....it wasn't. I'm not sure what you were reading, but it certainly wasn't anything that was posted here. In fact, the amplifier reviewed wasn't compared to anything. It was evaluated on it's own merits based on what Ameritron advertises that it will do.

 

[COBRA148FGTLDX+]

On your Icom 7000 setup with ALS500M did you have to have a relay buffer installed between radio and amplifier or was you able to hardkey it directly ? I just ordered a ALS500MR over the weekend and just trying to have everything ready to go .
We will be using a ICOM 7000 with our amp setup as well...

 

[Mudfoot]

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!

Illusions of grandeur...

 

[Moleculo]

On your Icom 7000 setup with ALS500M did you have to have a relay buffer installed between radio and amplifier or was you able to hardkey it directly ? I just ordered a ALS500MR over the weekend and just trying to have everything ready to go .
We will be using a ICOM 7000 with our amp setup as well...

No, you don't need a relay buffer. Just get an RCA cable, cut one end off and wire the center pin and ground on the RCA cable to the correct pins on the radio interface. Simple!

 

[The Mad Scientist]

Excellent review of this amplifier there Moleculo. I especially like the active bias tracking feature. Nice job. Although a bit pricey, you seem to get what you are paying for. The power drop off on the higher bands shouldn't be an issue if the bands are really going. But as you stated the lower bands are where the power is needed most. I may have missed it but were you using a screwdriver antenna with this setup?


I was amazed at the comment that was posted. Apearently it was from someone that dosen't realize that it isn't always about " brute power". Perhaps he could put his money where his mouth is and provide some pic's of this "magical" transformation?

The link to the manual dosen't work.


I would like to try one of the in the future.

 

[Moleculo]

I may have missed it but were you using a screwdriver antenna with this setup?

I use a Hi-Q antenna

The link to the manual dosen't work.

Fixed it - thanks for the head's up.

 

[The Mad Scientist]

ure, no problem.

 

[Jake Mok]

It looks cool in your Jeep!

Have you tested if the antenna is capable of handling the resulting output power? What did you do?

 

[Moleculo]

It looks cool in your Jeep!

Have you tested if the antenna is capable of handling the resulting output power? What did you do?

Yes, I used the antenna. It didn't explode In all seriousness, the antenna's published specs indicate that it is good for legal limit.

 

[Turbo T]

Nice review. I have thought of getting one of these myself. Hopefully with the Toshiba transistors.

 

[Sergeant Bilko]

Can this amp be used on FM mode? I've not been able to confirm this as the user manual only identifies CW and SSB

 

[Shockwave]

Can this amp be used on FM mode? I've not been able to confirm this as the user manual only identifies CW and SSB

Yes is can be used on FM.

 

[Slowmover]

Great thread. Thanks.

Best of all: I can’t afford it!

That’s good news. When you’re me.

Hell, I still have to finish my RADIO MUSEUM CURATION Certification. Build shelves. Install lighting. Wrangle up a website.

Got no time at all to swim out of the murky CB waters and get into that clear stream.. No, sir. Hah-ah.

Besides. I can’t hear y’all laughing at my Zing Ring from back here.

.