Texas Star Amp Repair free help

[KJ6KQE]

Mike;
Thanks for the advice and help with my 350 HDV. I replaced the transistor just like you said, and Viola! My amp keys up just like it's supposed to [insert grin here]. I worked so well, that I was able to get Argentina (don't cry for me).
I probably would have tossed the amp with great frustration, had it not been for your encouragement and guidance.
So, publically, let me say thank you for bringing back my amp from the dead [insert giant grin].

-Don

 

[k8cpa]

deleted post. Mods please remove thanks!

 

[KJ6KQE]

Does anyone know if the Texas Star 350 HDV can operate in the 160-10 meter range? or is it sequestered to the 10 meter band?

 

[NY739 Mobile]

: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

Hi mike. My name is Brian, and I was wondering if you could answer a few questions for me?
I have a Super Star 250 AB1 w/auto ssb behind a 148gtl into a 102 ss whip.
swr's are excellent. but when i put my RS watt/swr meter after the amp it shows only 100w dead key on am with a neg swing.... when i speak and when i talk on ssb it only swings to 100w....what i was wondering is if this is normal for this type of amp...according to my meter my radio only puts out 10w dead key on am..the couple of things i did notice is that (with the cover off the amp) when i key up and speak ther is a resistor from the middle leg of the High/med/low switch that gets so hot it looks burnt and when i switch from high to med the watts out dosen't change....i get good audio reports on ssb from all over the country but locally on am people tell me my signal has a little buzz in it....wondering if these things are related....i look forward to hearing your feedback....thanks Brian

 

[AudioShockwav]

You need to reduce the dead key on AM. Try about half what you are running now. The R/S meter is going to show AVG watts, not peak.
Try adjusting it for about a 60/70 watt dead key out of the AMP on high and see if it will swing forward.
The resistor you are talking about is to reduce the drive power to the input, and it is overheating due to excessive drive.
What output transistors is it using?
What size wire are you using and where are you hooked up at?
Can you snap a few pictures of the inside of the amp and post them here?

73
Jeff

 

[TonyV225]

Those SS250 models run a pair of SRF-3749 I believe. I know my old gold one did and the new ones I think had SD-1446 transistors

 

[NY739 Mobile]

You need to reduce the dead key on AM. Try about half what you are running now. The R/S meter is going to show AVG watts, not peak.
Try adjusting it for about a 60/70 watt dead key out of the AMP on high and see if it will swing forward.
The resistor you are talking about is to reduce the drive power to the input, and it is overheating due to excessive drive.
What output transistors is it using?
What size wire are you using and where are you hooked up at?
Can you snap a few pictures of the inside of the amp and post them here?

73
Jeff

I will deffinatlly try turning dwn the radio to half ( correct me if im wrong please...vr10 am = clock wise lower, vr11 ssb= counterclock wise lower), not sure what the transistor is...I do have the amp and radio hard wired to the Battery with 10ga wire...ill try to snap some picks after work today...thanks guys ill let ya know...

 

[NY739 Mobile]

I will deffinatlly try turning dwn the radio to half ( correct me if im wrong please...vr10 am = clock wise lower, vr11 ssb= counterclock wise lower), not sure what the transistor is...I do have the amp and radio hard wired to the Battery with 10ga wire...ill try to snap some picks after work today...thanks guys ill let ya know...

allright so I did some more testing....The out put on the gtl is only 5w AM and ssb swings to 10w....i tried turning them both down and it made no difference....I did take a couple pics though...then i proceeded to unhook the super star and chuck it against the wall of my garage....just kidding....I did however hook up my palomar tx150 without making any changes to any thing else (wiring,location,input,etc....) and it dead keyed at 100w am and swung 150w on ssb so im startin to think the super star amp is not so super (laughs out loud)anyway here are some pics to go with my confusion....:headbang
sorry about the quality...i had to resize them to be able to upload.......

I've been reading different stuff online , and the more I read the more I think my radio has some deeper issues......when I had my meter hooked to my radio without the amp and i oppened her up vr10 was allready turned all the way up and it showed a 5w dk..when i spoke it droped 1w instead of swinging up...when i turned vr10 dwn to 2w it would swing to 4w...ive read that a 148gtl should be more like 10w swinging 20w when turned up....????? help!

 

[AudioShockwav]

Yes if the radio is going back on modulation, you will need to get that straightened out before you can go forward with any Amp problem.
Sounds like you should find some one to do a correct alignment to the radio.
Also, i would not expect real big numbers with the R/S meter.
Where do you live?



73
Jeff

 

[NY739 Mobile]

Yes if the radio is going back on modulation, you will need to get that straightened out before you can go forward with any Amp problem.
Sounds like you should find some one to do a correct alignment to the radio.
Also, i would not expect real big numbers with the R/S meter.
Where do you live?



73
Jeff

I live around Rochester/Buffalo NY, I don't think that the radio has been touched by a good tech in prolly 10yrs or better....I'm open for any suggestions....

 

[Robb]

5 pin mic?
Nice!
Worth taking that radio to a shop and have them give it a alignment.
Sparky's CB Shop is in IL is pretty decent if there isn't anything closer to you . . .

 

[76Q]

Excellent resource and support structure, even from a retired employee. TS is best

 

[NY739 Mobile]

thanks for all the insite everyone.....I think what iv'e decided to do is purchase a 2970dx or mabye a new 2970n2, then send the old cobra to sparky for a good once over...I only have just one radio (my cobra), then I can keep my cobra as a spare (i really like my old beat up cobra)...any opinions on the 2970's?

 

[me999]

Does anybody have the phone number for Texas Star warranty repair ?

I had it but can't seem to find it.

 

[Hook948]

Does anybody have the phone number for Texas Star warranty repair ?

I had it but can't seem to find it.

Call Texas Star at (760) 480-8800