Texas Star 350HDV

[gary31525]

Hello everyone,

I'm having a problem with an amp and I can't figure out what's the problem. I got the amp and knew the pills were blown, replaced them, now here's the tricky part. I'm hoping someone here has had this problem:

Pass through is okay

SWR when amp is keyed up is 1.2 - 1.3

The amplifier relay and light rapidly turns on and off when on full power.

I can manually key the amp with a screwdriver and the relay and light do fine, but output is only about 180-200 peak.

If I turn the variable on (green button) and turn down the variable to about 3 o'clock, the relay and light does not rapidly turn on and off.

If I start turning the variable up slowly, the relay and light slowly start turning off and on and start speeding up as I turn the potentiometer up.

If I activate the pre-amp, the relay and light will not activate unless I scream or whistle into the mic, with or without the variable activated.

- - -

I know that's a lot of info, but I wanted to give as much as possible. Any help is appreciated. I've replaced all the keying components with new parts and I replaced the pre-amp transistor with a new one. I have my thoughts on what I think is wrong, but they have been wrong thus far so I'm looking for other thoughts and views.

Regards,
Gary

 

[Robb]

First blush?
Sounds like it is starving for current.

 

[loosecannon]

what is the SWR going IN TO the amp?

starving for current is a good guess, but im thinking it could be RF wreaking havoc inside that amp.
just more guesses here...
LC

 

[gary31525]

what is the SWR going IN TO the amp?

starving for current is a good guess, but im thinking it could be RF wreaking havoc inside that amp.
just more guesses here...
LC

I'm running 4 gauge wire straight from the battery to the amp with an 80 amp alternator. I'm thinking it's not starving for current, especially since it does better when manually keyed.

The SWR with the amp out of circuit is 1.1, but if you're asking what the SWR is with the amp in-circuit and the SWR meter between the amp and the radio, I haven't done that check. If that's what you're asking I'll hook it up and let you know.

 

[dx31353]

What radio are you driving it with? What is the dead key on the radio set at? What does the dead key read with the amp on?

Hooking up the meter between the radio and the amp and checking swr with the amp on will check your input tuning. Good thing to check also.

Sent from my SCH-I545 using Tapatalk

 

[psycho]

NEVER EVER adjust the variable in that Texas Star when the radio is keyed and the amp is on.

 

[gary31525]

What radio are you driving it with? What is the dead key on the radio set at? What does the dead key read with the amp on?

Hooking up the meter between the radio and the amp and checking swr with the amp on will check your input tuning. Good thing to check also.

Sent from my SCH-I545 using Tapatalk

I'm driving it with 3 watts from a Cobra 25 LTD. Thank you for that pearl of knowledge, I'm still learning and that is a valuable bit of info. I'll check that soon and let you all know.

 

[gary31525]

NEVER EVER adjust the variable in that Texas Star when the radio is keyed and the amp is on.

Okay, I'll not do that again, but what is the reasoning for that?

 

[M0GVZ]

I'm assuming this is a mobile installation? If so what is the antenna, how is it installed and what coax are you using?

 

[M0GVZ]

Okay, I'll not do that again, but what is the reasoning for that?

Several thousand volts. People have been killed having their hands inside an amp when its keyed up.

 

[Wire Weasel]

An 80 amp alternator isn't very big. What is the vehicle ? Some little subcompact thingy ??

Take the box out and run it on a base with 35 amp or bigger power supply. If it's all goo then, then you know it's starving for current on the vehicle. Get a bigger alternator.

Good luck

 

[CbRadiosPRONTO]

100 WAYS TO DIE FROM A TEXAS STAT DX350, THE LEAST OF WHICH WOULD BE PUTTING YOUR HANDS INSIDE OF IT.
1. Your crazy x-girlfriend drops it in your head from a fifth story window
2. You ate the Texas star and then Keyed up, although I still don't think keying up would kill you
3. You threw the Texas star out the 5th story window hoping to hit your crazy x-girlfriend only to realize you were a attached to the amp, you miss your crazy x-girlfriend survive the crash but the amp lands on your head
4. You don't survive the crash
5.



CbRadiosPRONTO

 

[Robb]

Okay, I'll not do that again, but what is the reasoning for that?

Because these rheostats are prone to failure even w/o that added stress and often do. You would just be forcing it to happen sooner due to the extra load stress on it. IIRC, they are rated @ 2w and should be 10w.

 

[GnG8d]

Several thousand volts. People have been killed having their hands inside an amp when its keyed up.

I see that 30 years in electronics with an honors degree has served you well

 

[GnG8d]

Okay, I'll not do that again, but what is the reasoning for that?

The VR is barely adequate to start, then you dragging the wiper across the resistive element while keyed exaggerates it's demise.