Texas Star DX500 non variable

[Caliman409]

I have a Texas star DX 500
What would be the maximum watt input to drive the amp? I have heard numerous conflicting stories . The amp has been modified, removing the 10 gauge wires and fuses , and instead installing four gauge wires with an external 50 amp fuse ,

 

[Shadetree Mechanic]

Welcome to WWDX! The maximum peak drive that the 500 will reasonably take is about 40w peak. Go easy on it and it will serve you well for many years.

 

[Caliman409]

Ok thank you, that sounds more reasonable , as I was told you can drive up to 100 W But I don’t want to burn the thing out , Thanks again

73

 

[543_Dallas]

You will continue to get different answers because some people like to loaf along, make things last and have a clean signal. Some will beat the hell out of an amp, keep driving it until it blows or stops making more power. Then you have everyone else in between.

If it were mine I would drive it hard enough to get 400 to 500 pep output and no more than 125 watts AM carrier. If your worried about splatter the 2879 has the best IMD characteristics at 60 watts pep.

I remember a guy that used to drive a dx500 with a 1 pill. He wanted to be the channel master but was a real moron.

 

[Caliman409]

Roger!!
Thank you!

 

[nomadradio]

There's a widely-quoted rule for industrial power equipment about power ratings and service life. Says that for every 20 percent beyond rating that you push it, you sacrifice half the service life.

Contrast this to the 'drag-racing' mentality that keeps coming up with linear amplifiers. Beat the other guy in a drag race by a tenth of a second and you're a big winner.

To make a difference in what they hear from your radio at the other end you need to double your power at minimum. Typically more than double.

Anyone who hears you with the amplifier at full throttle will hear you at half or 2/3. Probably won't be able to tell the difference.

Not much to be gained by burning rubber with a linear.

73

 

[Caliman409]

Makes sense, yes I read about that a while ago , they did tests , and the operator on the receiving end may be at the most saw a 1S unit improvement , I agree nothing to be gained unless you have the money to buy more pills !

 

[999]

The way I understand it is that you need to increase your power 4 times to see 1 S unit in the receiving end.

 

[nomadradio]

Math tends to put people to sleep. The short version is that a decibel is a measure of proportion. 3 decibels (db) is a two-to one power comparison. Six db is a four-to one. Nine db is eight-to one. Ten db is a ten-to-one ratio. Add three db to that and 13 db is a twenty-to-one difference.

The six db per S-unit standard is widely disregarded in the design of a CB or ham radio, but it's the "textbook" rule if the radio's S-meter is calibrated "by the book".

Frequently you'll see one S-unit is closer to 3db than it is to 6db.

But using a rule of thumb just makes it easier to explain.

73

 

[Ranch55]

I have a Texas star DX 500
What would be the maximum watt input to drive the amp? I have heard numerous conflicting stories . The amp has been modified, removing the 10 gauge wires and fuses , and instead installing four gauge wires with an external 50 amp fuse ,

I use several of these amplifiers in my pickup trucks and one on my satellite base station.
I typically set my radio at a 3~4 watt dead key on AM ......
Then just let the PEP watts from radio drive the TS 500 amplifier. I have been using two Stryker SR-955 HP radios driving these amplifiers like this for 3~4 years with good performance from the amps.
But, I did change the DEI 2879's out for Toshiba 2879's when I purchased the amps some time back.

 

[nomadradio]

But, I did change the DEI 2879's out for Toshiba 2879's when I purchased the amps some time back.

Probably why it still works.

73

 

[AudioShockwav]

Toshiba 2879 transistors can take a lot of abuse.
Nomad, I think it was you that posted pictures of a sweet sixteen one time that had got so hot the solder started to sag on the boards and parts were falling off.....
Might have been on the old cb tricks forum.

73
Jeff

 

[nomadradio]

Yep. Those pics evaporated in a disk crash, just before a scheduled backup.

Oops.

Was a really cool specimen, though. It had been mounted against the rear cab wall in a pickup behind the seats. When the solder melted, it ran downhill. Parts fell off. When I first picked it up and shook the thing it sounded like a maraca.

A transistor that will melt the solder off itself and still run is one tough cookie.

73