Understanding amp designs: Texas Star

[Wire Dawg]

Ok: Texas Star amplifiers have no output filtering. 1) Will somebody please outline any inherent pros/cons to such design approach? 2) Are the terms intermodulation distortion, harmonics, spurious signals, splatter & TVI one and the same? 3) What effect does a Bencher YA-1 LPF have when connected at the output of these amps? 4) What effect does a coax choke balun have when used at the antenna end? 6) If TS is used within their limitations (not overdriven), will there still be discernible adverse effects? I’m asking because, in addition to grounding my station & antenna, I have implemented all these measures to obtain the cleanest output possible (barring the purchase of amateur radio equipment). All was fine ‘till yesterday when, for the first time in my years in this hobby, I heard my voice coming out of the old toaster & PC speakers. It was not a hallucination. The hair on my terrier rose like a frightened porcupine and my ball python stood up like a flag pole. Even the rooster’s crow sounded like CQ, CQ, CQ when I keyed the radio this AM! Is the TS amp causing this anomaly? If so, how come it never happened before?

 

[North Texas Mudduck]

loose connection?
ground come loose??
does it go away with the amp off???
and its not a ab1 amp

 

[Wire Dawg]

Thanks you. Will check ground connections tomorrow. The PC speaker picks up my voice while the amp is turned off. The amp is advertised as class AB, and I never had problems of this sort in the past. I was trying an old d-104 when I first heard the noises, but they persisted even after returning to the stock mic.

 

[North Texas Mudduck]

as for the pc speakers they are pretty cheap
theres a disclaimer in the box.
right at the speaker wires where it goes into the speaker puts some snap on ferrites and it should calm it down


the amp is advertised as ab bais
but its more like B bias

 

[BOOTY MONSTER]

does it rain or snow before or during the splatter issues ? does your vswr change when they happen ?

 

[W5LZ]

Amplifier designs are fairly standardized, sort of. How far each manufacturer goes to follow that 'standard' design is a completely different story.
It also depends on each amplifier's particular design, some require more 'cleaning up' than others. That's because of slightly different circuitry or components used in each 'line' or model. I think the biggy is how 'frugal' a manufacturer/builder is. A penny here, a penny there, that sort of thingy. And how each builder 'customizes' their product.
I think it would be a very nice thing is there were a set of standards that had to be met. But with 'CB' amplifiers? You can forget that, there are no standards! There won't be until they are legallized, and I think you can forget that too...
- 'Doc

 

[unit_399]

Amplifier designs are fairly standardized, sort of. How far each manufacturer goes to follow that 'standard' design is a completely different story. - 'Doc

Doc -

Since we're talking transistor amplifiers here, please show us what is the "STANDARD" design to which you're referring ?? Who generated this "standard" originally ?? Is it class AB, B, C, or what??

- 399

 

[W5LZ]

What difference does it make if it's a transistor or tube type amplifier? For that matter, the 'class' of amplifier makes no difference either. There are no 'set', 'recognized', established standards for 'CB' amplifiers. Probably the only criteria for them is that they can be marketed, what will 'sell'.
There are only 'standards' set by the sellers and users. If the user isn't aware of at least a little bit of what's possible then the seller is the only determining 'authority' for those standards. That typically means 'good' is whatever 'they' say it is, and that can bite you very quickly.
The key to this is that "CB amplifier" thingy. See what I'm talking about?
- 'Doc

 

[Wire Dawg]

Booty Monster: We've have had rain and snow for the last week. What role does rain & snow has in these problems? If anything, I would expect rain/ snow to somehow improve conductivity of the ground rods due to wet terrain.

I'm aware of the manufacturing issue with PC speakers. But the fact remains that I never had interference with PC speakers before, or at least, not to a noticeable level. Never had the toaster talking back to me. If I can hear it in mine, then there is a good chance that the neighbor's toasters may be talking too.

This amp uses Toshiba 2sc2879 transistors only, and it is less than 6 months old. My older TS amps never gave me this kind of feedback, hence the reason I bought another. I will be looking into the ground issue today. I am still curious as to the different types interference that may stem from TS or unfiltered amp designs in general, and how to minimize them.

 

[Beetle]

What difference does it make if it's a transistor or tube type amplifier? For that matter, the 'class' of amplifier makes no difference either. There are no 'set', 'recognized', established standards for 'CB' amplifiers. Probably the only criteria for them is that they can be marketed, what will 'sell'.
There are only 'standards' set by the sellers and users. If the user isn't aware of at least a little bit of what's possible then the seller is the only determining 'authority' for those standards. That typically means 'good' is whatever 'they' say it is, and that can bite you very quickly.
The key to this is that "CB amplifier" thingy. See what I'm talking about?
- 'Doc

There are no industry standards for illegal equipment, meaning CB amplifiers.

 

[Ratfink]

There are no industry standards for illegal equipment, meaning CB amplifiers.

So your saying that CB is the only band that uses illegal amplifiers ?

 

[suzerain]

Texas Star's are 10 mtr. amps that have to be altered for non-cw use.
They are not illegal and should be built to a high standard.
I don't hear anything coming out of my toaster with my DX-500V on high,
only through one pair of my many pairs of speakers around the house.

 

[W5LZ]

Is CB the only place you find illegal amplifiers? Of course not, but that's where you will find all of them by definition! Those same amplifiers are not illegal on 10 meters. Which still doesn't mean that they meet normal specs/standards.
You can call them '10 meter' amplifiers if you want, but just like the '10 meter' radios they are only a 'get around'.
- 'Doc

 

[Wire Dawg]

I've been using Texas Star amps for years, and never had complaints of interference, bleeding thru other channels or bad reports. Have heard messed up signals on channel 6, which invariably are tied to class C amps, often driven beyond its limits. I'm worried that my station is suddenly acting up.

As difficult as it may be, I'd like to ask to set aside Part 95 provisions about legality of using these amps on 10/11 meters. Short of getting my license and spending $$$ on bona fide ham equipment, I want to better understand these amps and how to minimize or eliminate any intermodulation distortion, harmonics, spurious signals, splatter or TVI (clarification of these terms would be appreciated). I have installed a Bencher YA-1 LPF, a coax choke balun at the antenna end and grounded the hell out of the tower and equipment for the sole purpose of avoiding ill effects. I do not overdrive my amps. Why is my toaster vibrating? BTW, I have a brand new MFJ-931 at my disposal: just need instructions how to use it.

 

[Beetle]

I've been using Texas Star amps for years, and never had complaints of interference, bleeding thru other channels or bad reports. Have heard messed up signals on channel 6, which invariably are tied to class C amps, often driven beyond its limits. I'm worried that my station is suddenly acting up.

As difficult as it may be, I'd like to ask to set aside Part 95 provisions about legality of using these amps on 10/11 meters. Short of getting my license and spending $$$ on bona fide ham equipment, I want to better understand these amps and how to minimize or eliminate any intermodulation distortion, harmonics, spurious signals, splatter or TVI (clarification of these terms would be appreciated). I have installed a Bencher YA-1 LPF, a coax choke balun at the antenna end and grounded the hell out of the tower and equipment for the sole purpose of avoiding ill effects. I do not overdrive my amps. Why is my toaster vibrating? BTW, I have a brand new MFJ-931 at my disposal: just need instructions how to use it.

If it's brand new, the instructions should have come with it. If not, go to the MFJ website and download and print a copy of the instructions. It's there.