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Texas Star Amp Repair free help

To find someone knowledgeable that's willing to work on CB amps is rare enough. Combine it with honesty and no attempt to rip off, that's amazing. I've seen so many cases where people put more effort into establishing a reputation of "amp builder" then they do establishing a reputation for understanding RF amplifier design. Nine out of ten of these guys can't even explain the theory behind negative feedback or proper biasing let alone make any improvements in there design.
 
:bdh:
a quarter century with Texas Star, and I have been put to pasture.
I did tech support for about 10 years. I am sure that some of you must know me.
It is my intention now to help techs and hobiests to repair a stock TS amplifier. I am not an engineer and there are things which I will not debate. However, I can usually fix one and not to have it blow itself up again.

I have made the simplest of web pages which I invite you to. Go to the troubleshooting page and pick up some pointers.
You can e-mail me with questions. I really like a digital picture with your question as a picture can be worth a thousand words. I may be able to recognize modifications or vintage of manufacture, or maybe even see a short or open from the pic.
I will try to come in here occasionally and look at the threads.

Remember, when you replace transistors on a Texas Star amp you need to check the bias circuit or you may just blow the replacement finals.
1 extra minute is all I suggest. Read the bias resistance, then manually key up and read the bias voltages.
GO to YouTube and look for Texas star Amp Repair
you will find manual key-up procedure and bias check procedure.

My name is Mike and I hope that I can help some of you.

TexasStarRepair@cox.net
Home Page

Wish I had known about you a couple of years ago... I've managed to blow up a 350, a 667 and a Sweet 16... sold them for parts :( LOL... Took me a while to figure out the drive limitations of the that bias. Will definitely read your site over with some interest.
 
Welcome to the forum and thanks for taking the time to join and most of all thanks for offering your help in these particular amplifiers. Im a huge fan and the Texas Star amplifier is my favorite and pretty much all I will run in this type of amplifiier I have 2 straight (non variable) DX500 1 DX400 and a new 1600 with the accesories fan kit remote head ETC. Ive had great luck with these and they are reliable as all get out although I run fans on all mine.

I do have to put a new set of push buttons on the last 500 I bought but it was like that when I bought it all in all it still works.
 
Mike I'm glade to have found you again I can say this man is the best there to offer He in Honest and willing to help He is worth his weight in gold. I know him when he worked with Texas Star, There loss He has worked on my amps and also sent me parts to fix my own amps and is not a rip off. I can't say enough about him Those of you that haven't had him work on there equipment are in for a great experiance. I know that he has all my support and work now that I have found him again. RJ FLORIDA
 
Ok, here goes. I was going to send this DX250HDV to you with a note to check it and if too expensive I would just let you keep it for parts and buy a new one.

It was chattering so fast it sounded like a bee. I replaced the keying transistor with a new one and the exact same. I was playing with it to see what I could find before sending it in so I can write on the note all I can to help dianostics. I noticed that the thing was getting more and more dim, lights in the push buttons and meter light. The power supply amp needle was going down when I keyed up. I though I would check all connections to power supply and when touching the positive wire from power supply to amp it felt very hot at the fuse. I tried to pull the fuse out but just could not by hand so I just pushed it in real hard.

I could not believe it, the lights got bright and it started keying fine for a few seconds and then started chattering and dimed out again. I sqeezed it in with my hand and as long as I did this it worked. I can't hold it down long as it burns my fingers.

I think if I replace it with a new power supply wires with a fused pos wire in heavy gauge it just might do the trick. I think it is worth a try. Now where and how much for a new set of wires for this amp?

Any one else have a problem like this?

AP
 
I burned my finger good. It acts like the fuse holder is not making real good contact. What size should the fuse be?

This is stupid, I just got it to do 200 AM and about same on SSB.
 
t/s

Hi, im new to post, anyway Thanks Mike lots of good info.I have an old sweet sixteen that has many patches lol but still works.
 
hello Mike welcome to the forum i had run into you a few months back and you sent me a resistor for my 350 hdv but i think one of the pills got damged in testing before hand so its just on the back burner for now
i will go threw your notes on your site and see if there is somthing i missed in the emails you sent me
thanks for all the help so far ;)
 
dx500

Hi Mike, I would like to hard wire my dx500 so the relay closes when I key the mic instead of with RF.
If we can leave the rf activated circuit intact, so much the better.
Is there an easy way to do this?
I just need two wires coming out of the amp that when shorted key it and unkey it when released.
Any ideas or comments appreciated.

rgds,
dave
 
It is working perfect now that I cut the fuse out of line.

I've said it once, I've said it a thousand times. Texas Star uses BULLSHIT fuseholders!

Those crappy AGC auto fuse holders are ONLY good for 15A. After 15A, the spring inside starts to lose temper and then loses tension. Leading to the EXACT problem being described here.

Your fuse goes at the POWER SUPPLY side of the amplifier, not at the amplifier...: ESPECIALLY in a mobile environment. They include a fuseholder for for liability purposes, but otherwise, it does no good if the power lead gets pinched between the battery and the amplifier (which is what the fuse is suppose to prevent: Those are MOBILE amplifiers.)

If you really want to fuse your amp, get an AGU fuseholder, minimum. You have a 40A draw with a pair of transistors (peak), and you need a fuseholder that can hold 40A, not one designed for 15A and being pushed to 3Xs it's rating because of "ICAS" crap that no CBer can even tell you what it means, much less what it's for.

I also have LARGE AGC fuses, up to 100A a piece. Amazing how fast you can burn the fuseholders up with 40A fuses in a Texas Star 667. The amplifiers really want more than the fuseholders can pass.

--Toll_Free
 
Hi Mike, I would like to hard wire my dx500 so the relay closes when I key the mic instead of with RF.
If we can leave the rf activated circuit intact, so much the better.
Is there an easy way to do this?
I just need two wires coming out of the amp that when shorted key it and unkey it when released.
Any ideas or comments appreciated.

rgds,
dave

You need a pair of steering diodes to accomplish what you want.

The TS keying circuit keys the negative lead of the relay. Just bring a lead out from the linear that when you ground it, it will allow the relay to close. You need the steering diode in line to keep the keying transistor in line. You can figure out which side you need to ground with a multimeter and keying the linear. One side will go to ground when you key it, and both sides will be hot when it's unkeyed.

You'll have to cut the trace leading to the KEYED side of the relay, and put a diode in series with it. This will block the keying pulse from the outside key circuit. Do the same on the (I use) RCA jacks on the amplifier for the "ground to key" line. Problem solved.

I pull my keying xisters. Hard key line everything.

--Toll_Free
 

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