Texas Star Amplifiers in legit use.

[KA5PIU]

Hello.

I was surprised to learn that 99% of all hams as well as CB shop operators have no concept of how to correctly configure a Texas Star CW unit/Amplifier for a clean AM signal.
http://www.texasstar.com/350HDVschematic.gif
First off, notice that this is indeed configured as a CW Transmitter.
Notice also that this has a key/audio input.
We go from J1 to R6 to Q3 to C17 to Q4 to C11 to T1.
We also go from J1 to R6 to Q3 to X1 and R9.
SW 4 selects where the audio signal goes.
As you can see, this thing can do CW, AM and FM.
In the AM mode it is true high level modulation, T1 acting as the modulation transformer.
In FM mode it deviates the crystal X1.
There are 2 more boards that must go in to make it a 350 watt PEP AM transmitter.
A modulation amplifier and driver amp.
This does around 60 watts carrier so the modulation amp is around 30 watts.
In FM mode nothing extra is needed.
This is NOT an SSB amplifier! it is class C !!!!!!!!!!!!!!!!
You can do the external exciter mod and do FM or CW with no problems whatsoever.
But for AM it is very important that it be modulated directly for a clean signal.
To say it has no filtering is not correct, the output transformer limits the frequency of operation to a maximum of of about 30MHz as well as the fact that gain drops off very quickly.
Since this is a 10 meter monoband transmitter/amplifier nothing else is needed.
Operation on 26.62MHz in the FM mode works well within specifications required.
On AM with the 2 extra boards it meets all NTIA requirements.
Again, this is a monoband unit, operation outside of 22MHz to 30MHz is not an option.

[KG4CGC]

bullshit

I said it first

WART
(worked all Rudy threads)

[WØTKX]

[PA5COR]

Yuck.
I prefer my Heathkit SB-1000.
Clean output and all.

[VE7DCW]

bullshit

I said it first

WART
(worked all Rudy threads)

I love it!!! ...... WART a new twist in the measurement of WTF's in all of Rudy's threads!! Bravo!!

[NQ6U]

WART

[KC2UGV]

Well, I'm sure it can be done. I mean, after dumping $10K into a rice-burner, it gets in the neighborhood of a stock Mustang with a 5.0...

[N2CHX]

Want clean output from that thing? This should do it:

                          100 mH
AMP >---------------UUUUUU----------------------- > ANT
              |                              | 
              >                             __
              < 50 ohm                      __ .1 uF 
              >                              |
              <                              |
              |                              |
             ___                            ___
              -                              -

:stickpoke:

[PA5COR]

I prefer a sledge hammer to that...

[N2CHX]

I prefer a sledge hammer to that...

Well... Admittedly you'd probably get more output