Texas star dx 350 hdv staying keyed up after transmission.

[snippits75]

On the other hand, I have experienced just changing radios will make the amp happy with the same length jumpers.

For what ever reason, I have had more trouble with high powered radios causing problems. Hook up my Cobra 142 GTL, and problem goes away using the same length jumpers. And on high powered radios that do cause problems, a half wave length jumper of RG-8X makes the amp behave.

 

[groundwire]

I use a two full wavelengths jumper for my amp, then it works.

 

[linearone]

I can run a 6 inch jumper to 60ft jumper betwen my radio and amp and everything else and nothing changes. I have NEVER had a piece of radio communications equipment malfunction or self destruct due to coax length. Hmmmmm, strange.

It only matters sometimes. It usually occurs when the load is not perfectly 1.0 50 ohms.

As a rule of thumb, I like to look up the vf for my coax and cut them in even multiples of a wavelength, usually 1/4wave. Sometimes I use 6fts too. Typically never 3 fts.
The last time I saw something weird was with a three ft jumper a few weeks ago.

 

[linearone]

Also, if you have an MFJ or one of those fancy vnas you can measure exact multiples instead of relying on a tape measure

 

[rflegacy]

Im not concerned in the least bit. I guess Cheap cb equipment does those kinds of things.

I never knew a galaxy 959 with a predator 10k antenna and a Texas star amp were cheap cb equipment.

 

[brandon7861]

I never knew a galaxy 959 with a predator 10k antenna and a Texas star amp were cheap cb equipment.

The amp, quality cheap, not price cheap. It uses two 2sc2879's, and to get the advertised 350w out of it, you have to drive the absolute snot out of it. Those transistors have the best IMD performance at about 60w out each (per the datasheet), but at 175w out each, lol, off the datasheet charts completely. The distortion products are likely less than 20dB down.

They put at most $80 worth of parts into a box that costs you $350 knowing full well it will splatter on everything, and they couldn't even include a LPF to catch some of the junk. It would have barely increased their build cost to do so, but it is not worth it to them. They don't want that filter because its illegal already, and the only way you get 350w out of that amp is if you count the harmonics and other trash, which wattmeters do. And since most people think they have a bad ass amplifier, they push it even harder than recommended.

Cheap. There is no other word to describe those amps.

 

[rflegacy]

The amp, quality cheap, not price cheap. It uses two 2sc2879's, and to get the advertised 350w out of it, you have to drive the absolute snot out of it. Those transistors have the best IMD performance at about 60w out each (per the datasheet), but at 175w out each, lol, off the datasheet charts completely. The distortion products are likely less than 20dB down.

They put at most $80 worth of parts into a box that costs you $350 knowing full well it will splatter on everything, and they couldn't even include a LPF to catch some of the junk. It would have barely increased their build cost to do so, but it is not worth it to them. They don't want that filter because its illegal already, and the only way you get 350w out of that amp is if you count the harmonics and other trash, which wattmeters do. And since most people think they have a bad ass amplifier, they push it even harder than recommended.

Cheap. There is no other word to describe those amps.

Oh so a fat boy and a carl built dont splatter?? Don't they use 2sc2879s? What are you talking about.... tube amps? Might want to go rant on a ham forum or kick rocks.

 

[brandon7861]

Oh so a fat boy and a carl built dont splatter?? Don't they use 2sc2879s? What are you talking about.... tube amps? Might want to go rant on a ham forum or kick rocks.

I didn't say anything about those who own texas star amps, did I? I own two splatter boxes myself and I don't give a shit what gear you run or whether or not the salesman spit on it first. I own a Chevy, and Chevy's suck nowadays, but I'm too broke to own anything nicer, so thats what I drive. Get over it dude.

 

[SuperLid]

I never knew a galaxy 959 with a predator 10k antenna and a Texas star amp were cheap cb equipment.

Now you know.

 

[brandon7861]

@rflegacy

You got offended when someone called TS "cheap" and all I did was agree with my opinion on why I think that is true.

If three box builders cut the same corners and make the same financially motivated business decisions, is that the new definition of high quality? Is that the new gold standard?

Are you suggesting the people who put time and effort into building legit and clean amplifiers are somehow worse people simply because they want to avoid legal issues and get paid for their knowledge and skill?

Talk bad about ham operators and their equipment all you want, they are just radio enthusiasts too. Go take your test and get your ticket, I won't think any less of you. Most hams do it for the challenge and passion, not because they are hell bent on following the rules.

 

[rflegacy]

I didn't say anything about those who own texas star amps, did I? I own two splatter boxes myself and I don't give a shit what gear you run or whether or not the salesman spit on it first. I own a Chevy, and Chevy's suck nowadays, but I'm too broke to own anything nicer, so thats what I drive. Get over it dude.

10-4, I hear ya. 73s

 

[nomadradio]

A few years back a CB customer got interested in a QST magazine. Found the Ameritron ad for their 600-Watt ham linear and was shocked at the price. Told me he could get a 600-Watt linear for a third that price. I told him the Ameritron had three times as many parts in it. You get what you pay for.

73

 

[Enterprise312ok]

They put at most $80 worth of parts into a box that costs you $350

That may have been the case 25 years ago but I can assure you as someone in the business that the margins are razor thin these days.

 

[linearone]

That may have been the case 25 years ago but I can assure you as someone in the business that the margins are razor thin these days.

They sure are. Unless youve got a direct hookup on certain things you are certain to lose money. All the internet builders that you see building amplifiers out of ICA manufacturing components, every one of those guys is losing money. If you have to pay retail for all the parts and you think you're making a profit? That just means that you value your time at zero.

 

[brandon7861]

This is just my opinion.... I wasn't referring to the smaller shops making a couple boxes a month. Of course the margins are razor thin when component and hardware quantities are in the tens to hundreds rather than the thousands likely contracted directly through the manufacturer. If I were to price out enough stuff to build one box from mouser or some supply house, making a profit isn't likely.

They (palomar TS carlbuilt etc) probably don't market illegal gear to the masses for razor thin margins. They make bank before they get put on notice. Thats the incentive to be cheap and it will never change.

And I'd bet those of you here making a few boxes as a side hustle probably do a much better job than these mass produced box builders anyhow.