Texas star 1200 or 1600

Robb · Apr 3, 2012

rabbiporkchop said:
According to Toshiba the 2sc2290 is a 60 watt transistor without harmonics. I'm sure lots of people see 200 watts out of a 2290 with 10 percent of that power on the fundamental frequency.

One thing to keep in mind, is that those spec sheets were written with a 12v reference voltage. Now, no one runs their amp or radios @12v. Most run them @13.8v or higher. When keyed, that voltage will drop according to the quality of the power supply - be it a vehicle's electrical system or the AC to DC supply. Think it is fair to say 70 watts @ 14.1v isn't much of a stretch with a stout supply.

I agree with you about amp mfrs will give watt ratings with no consideration at all as to the cleaniness of the output. An 8 pill 2290 amp with decent biasing (al la Texas Star) @14.1v (voltage drop estimate) should put out ~560 watts with a clean input source. But who considers having a clean signal? Yes; any operator that has been around awhile at this sort of thing - should certainly know better than being satisfied with over-driving the amp! I prefer to put out 120 watts of clean output rather than 240 watts of nasty harmonics and a crappy sound when transmitting. But that - is me . . .
:mellow:

AudioShockwav · Apr 3, 2012

I just made this post in the other thread, and I will re-post it here as well

They have changed the data Sheets since the second generation of 2290/2879`s have come out.

They "now" rate them at 60 watts for the 2290 and 100 watts for the 2879.

This Page At RFParts.com Transistor Specifications at RF Parts Company
Shows the old numbers At 80 and 120

This Page Shows the New numbers for the 2290 @ 60 watts
And the 2879 @ 100 watts if you click the links to the "new" spec sheets
2SC Transistors at RF Parts Company

The original 2290 was a 80 watt final, and the original 2879 were a 120 watt final.

The thing is, the data sheets reflect "min" specs at 12.5 volts in a test jig.
We all know they will exceed the minimum values in the data sheets, even more so at the nominal voltage put out by today's auto`s typically more like 13 to 14 volts with the engine running.

Texas star rates the DX 1200 at 900 watts out with 100 watts of drive
They rate the DX 1600 at 1200 watts out with 100 watts of drive.

Texas Star Export Feature Chart

I feel they are pushing it a little, but I disagree with the statement that a 1200 will only do 480 watts peak envelope power ... AVG... I will go for that but not PEP.
I think the terms pep and AVG get tossed out there together too much.
There IS a difference in the 2 terms.

73
Jeff

I agree.

73
Jeff

Eastside · Apr 4, 2012

rabbiporkchop said:
According to Toshiba the 2sc2290 is a 60 watt transistor without harmonics. I'm sure lots of people see 200 watts out of a 2290 with 10 percent of that power on the fundamental frequency.

My bad....I thought you were talking about the sweet 16 and the 8x2879.

AudioShockwav · Apr 4, 2012

I wanted to show you guys what the difference is between AVG ( average ) watts and Peak Watts.
The Bird 43 is a well know watt meter, and Bird makes a Peak reading kit for it.
So you will have a meter that will read AVG and then you flip the switch and use the same meter to read Peak.

This Video is about a cobra 29 with a RFX kit on it, i am using it just to show the difference in reading with the same meter on the 2 different settings.

Cobra 29 LX with RFX-75 for Pallet Burner - YouTube

You will note the guy making the Vid, uses the term RMS....this is not what the Bird reads when it is not in the peak mode, it is a term often used in error when talking about RF power measurments.
RMS or Root Mean Square is a way to measure voltage and current.
Not a way to measure RF.
( see links at the bottom of post)

The Bird only reads 2 ways...Avg or Peak.
There is another way to read RF power, it is called PEP
Or Peak Envelope Power.
The Bird watt meter will not read PEP power, to do that you need a Oscilloscope.

If you have ever wondered why in the Radio world there is so much difference in My radio does this, or my amp does this on my meter and that on his meter or something....well you get the Idea.
Then toss 5 or 10 different kinds of meters, not just a Bird, maybe a dosy, or a radio shack, or a astatic, or a heathkit, or a Yaesu meter....

73
Jeff

for more Information about RMS, please click this Link, and read up on the subject.
http://www.eznec.com/Amateur/RMS_Power.pdf

For those that do not want to read the entire article...
(I would recommend that you Do read it, it has some good info in it.)
It can be summed up at the end.

Summary
I’ve shown that:
 The equivalent heating power of a waveform is the average power.
 The RMS power is different than the average power, and therefore isn’t the
equivalent heating power. In fact, the RMS value of the power doesn’t
represent anything useful.
 The RMS values of voltage and current are useful because they can be used
to calculate the average power

For More Info about how to make PeP measurements Click this link
A Simple PEP Measuring Procedure

For some Good reading about a summary or overview of the different types power level measurements that can be made - average power, pulse power, peak envelope power, PEP power.......
Click this link
RF average, pulse and peak envelope power measurements :: Radio-Electronics.Com

unit_399 · Apr 6, 2012

AudioShockwav said:
I wanted to show you guys what the difference is between AVG ( average ) watts and Peak Watts.
The Bird 43 is a well know watt meter, and Bird makes a Peak reading kit for it.
So you will have a meter that will read AVG and then you flip the switch and use the same meter to read Peak.

This Video is about a cobra 29 with a RFX kit on it, i am using it just to show the difference in reading with the same meter on the 2 different settings.

Cobra 29 LX with RFX-75 for Pallet Burner - YouTube

You will note the guy making the Vid, uses the term RMS....this is not what the Bird reads when it is not in the peak mode, it is a term often used in error when talking about RF power measurments.
RMS or Root Mean Square is a way to measure voltage and current.
Not a way to measure RF.
( see links at the bottom of post)

The Bird only reads 2 ways...Avg or Peak.
There is another way to read RF power, it is called PEP
Or Peak Envelope Power.
The Bird watt meter will not read PEP power, to do that you need a Oscilloscope.

If you have ever wondered why in the Radio world there is so much difference in My radio does this, or my amp does this on my meter and that on his meter or something....well you get the Idea.
Then toss 5 or 10 different kinds of meters, not just a Bird, maybe a dosy, or a radio shack, or a astatic, or a heathkit, or a Yaesu meter....

73
Jeff

for more Information about RMS, please click this Link, and read up on the subject.
http://www.eznec.com/Amateur/RMS_Power.pdf

For those that do not want to read the entire article...
(I would recommend that you Do read it, it has some good info in it.)
It can be summed up at the end.

For More Info about how to make PeP measurements Click this link
A Simple PEP Measuring Procedure

For some Good reading about a summary or overview of the different types power level measurements that can be made - average power, pulse power, peak envelope power, PEP power.......
Click this link
RF average, pulse and peak envelope power measurements :: Radio-Electronics.Com

EXCELLENT POST JEFF

- 399

psycho · Apr 7, 2012

gamegetter said:
the four pill could probably also be run on the mag mount wilson 5k provided that you have a good rf ground, ie bonding of hood, trunk, & doors and proper grounding of body to frame...the 4 pill would prolly be the biggest amp i would try running on the mag mount, after that hard mount. ymmv...in other words each install may present it's unique challenge and you may have to hard mount for a 4 pill.

i like the xforce tnt1500. You have the extra battery to run it. but as already mentioned it likely will not make a great difference over the 4 pill.

The actual gain difference between a 4 pill and an 8 is 1/2 of an S unit.
Half an s unit is big when have a mobile keydown or when you are trying to talk long groundwave.....other than that, not noticeable.
The TNT 1500 is a nice piece!

Keikiokalani · Nov 10, 2019

you need 15 watts dead key

Onelasttime · Nov 10, 2019

Eastside said:
8 pills will do more than 480.

Not if you plan on using it every day for a decade or more with out letting the smoke out. Also do you want a clean signal or to sound like you just came from the dentist or a a splatter box?

I can almost guarantee that rfx75 has impedance matching problems since it's big brother's always did. So you have a driver with impedance issues going into questionable coax and then into a 12-16 transistor amp of questionable design with questionable transistors that have not been beta matched? What could go wrong?

Only a moron operates their gear at the limit or even near it. That would be like driving your car around at redline every place you go! What gear you buy and how you operate it is an IQ test if you know it or not! It also affects your pocket book.

In vest in a modern LDMOS amp. Under drive it and 20 years from now when it is still kicking butt you can thank me! Do not invest in technology that is 3-4 decades obsolete. Not unless you have a stock pile of parts and such your sitting on.

Onelasttime · Nov 10, 2019

If you get a TS and want it to last you would need to redo the input tuning, narrow down it's band width with tuned input and output more like a tube amp and think about changing the combiner network. 99% of people in the builder world wont do it right because they are starting from a bad design and copying that as if it is correct. You do not want to have a transformer coupled amp that has .3 to 50Mhz bandwidth. Not if you like efficiency and thermal control. You also should think about a low impedance transistor bias feed instead of sandbars for bias but that is just me. Clean is mean and cool runs for a long long time!

Onelasttime · Nov 10, 2019

Either buy a Henry SS-750 or have someone build you an amp like it. Do the maintence and 20 years from now thank me!

AudioShockwav · Nov 10, 2019

Good luck finding a Henry Solid State amp now days.
Not to often will you find one for sale.
And there are not many solid state builders around now that have the skill to build a properly biased amp with electronic voltage regulation, temp tracking, over heat protection, overdrive protection, overvoltage protection and proper input / output tuning.
I can only think of one person off the top of my head, and you are going to have to pay him well for his expertise.
Most CB guys will not spend that kind if money.
And then they will not be happy with the numbers they see, because there buddy has a 8 pill class c amp running on high volts that will do 600 watts more regardless of the signal quality.
Along with getting pissed off when they overdrive it and it keeps shutting down.
Honestly, lots of guys that have the skill to build a very nice amp will not do it anymore because they have had to put up with the Bullshit from operators that don't run there equipment properly or think they should be getting more power out for the money they spent.
73
Jeff

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