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Airplane1
Senior Member
Username: Airplane1

Post Number: 1069
Registered: 5-2004


Posted on Saturday, August 23, 2008 - 7:36 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have a friend who has a ts250hd and he was running it on a 25 amp power supply and kept it set on low all the time till he got a bigger power supply to run it on high safe.

The amp was not running hot and he had a fan on it too just to be sure it runs cool, did not push it with more than 2-4 watts in and it is not swinging real high either.

I guess all this said to say it just stoped working, it lights up and the pre amp works great. It just does not put out a thing. I heard that the var. power switch goes out on these amps if run on lower powers.

How do I know, what do I check?? please help.

Thanks,
AP
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2585
Registered: 1-2005


Posted on Saturday, August 23, 2008 - 1:48 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Airplane, A 50 cent repair! Have had this exact same problem with 3 Texas Star amps. It just stops working for no reason. No RF to turn on the meter light and no relay clicking?
I consulted Mike in Escondido, California about this. Mike is the repair man for Texas Star.
He told me that Texas Star had got a bad batch of the PN2907A keying transistors a while back. They have a high failure rate and this issue is very common to Mike. They trannys are also used in the receive circuit as well.
They are easy to spot becuse they are they only 2 PNP transistors in the box. The one closer to the back of the amp is the key and the one near the front of the amp is the receive.
They are easy to replace if you can solder. I used a pair of tweezers and a steady hand. Bend the outer legs of the new tranny in an L shape, make little feet to solder on top of the board. The center leg goes into the board. Only takes a little heat to solder in place so be quick. Note the position of the old tranny and put the new one in exactly the same, this is vey important! After the swap all the amps have worked perfect. I went ahead and replace the receive tranny also, just in case.
You can order the transitors for like 50 cents a piece online, you can call Mike and he will send you a couple for no charge or maybe even get them at your local Electronics Shack.
If your not to excited about doing the repair yourself then call Mike @ 1-760-480-8800. He will give you his address. Most likely the repair is no charge.
I mailed a DX500 out to him USPS and with insurance it was like 15 dollars! I was back on the air in 2 weeks!
Good luck and if there is anything I can do to help you out just let me know.
Kenny
CEF491
Mudduck County
Indiana
The Hotwire Mobile coming soon to a radio near you!
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Tech808
Moderator
Username: Tech808

Post Number: 16016
Registered: 8-2002


Posted on Saturday, August 23, 2008 - 3:53 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Kenny,

Not shure if Mike is still with Galaxy but the Number is the same and you shoud get Copper Forum Member:

Grts / Ray
Galaxy Radios Tech Support
e-mail: TechSupport@GalaxyRadios.com


Consumer Electronics
Galaxy Radios & Texas Star Units
1-760-480-8800
RMA number not required


Hope this help's,
Lon~Tech808
CEF#0808/HAM#001/CVC#0002

Tech808@copperelectronics.com
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Airplane1
Senior Member
Username: Airplane1

Post Number: 1070
Registered: 5-2004


Posted on Saturday, August 23, 2008 - 9:02 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks, I will give a call to that # and see what I do for my friend. I sure hope thats all it is.

AP
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2586
Registered: 1-2005


Posted on Sunday, August 24, 2008 - 2:07 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Lon, The last time I talked to Mike was about 2 months ago. A lot can happen in 2 months I guess. I hope Ray is as good with customers as Mike was.

Thanks
Kenny
CEF491
Mudduck County
Indiana
The Hotwire Mobile coming soon to a radio near you!
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Airplane1
Senior Member
Username: Airplane1

Post Number: 1071
Registered: 5-2004


Posted on Tuesday, August 26, 2008 - 7:01 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hotwire I called the # you gave me and talked to a tech named John. He was very nice and talked me though testing it to see if the transitor is the problem. It was like you said Hotwire, The resistor is bad and he is sending a new one free.

Thanks very much for this help, I am so glad I belong to this fine group.

My friend is very happy.

AP
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2589
Registered: 1-2005


Posted on Tuesday, August 26, 2008 - 11:25 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Your very welcome Airplane1.
Remind your friend to take care doing this repair. Removing the old and replacing the new is a bit tedious. Careful not to burn neighboring componets with the iron, its a tight fit.
The tech should send some instructions to help. Make little L shaped feet on the 2 outer legs and solder them to the board. The center leg pokes into the pin hole on the board, then you solder it into place.
Make sure the new transistor goes in just like the old one!
73
Kenny
CEF491
Mudduck County
Indiana
The Hotwire Mobile coming soon to a radio near you!
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Airplane1
Senior Member
Username: Airplane1

Post Number: 1072
Registered: 5-2004


Posted on Friday, August 29, 2008 - 7:32 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Well I ended up soldering it in for him, he is very unsteady in his ripe old age. Anyhow, I made little feet on all three legs of the trans and it took very little heat to get them on the board. I Sat one foot at a time on the glob of solder still there from when I took old trans off, touched the iron on one glob at a time while pushing one foot at a time down into it and had it done in about a min.

The amp works great now and the Tech sent two of the transitors so if the recieve trans goes my friend has the new replacement for that too.

Thanks again,
Roger
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2591
Registered: 1-2005


Posted on Friday, August 29, 2008 - 12:42 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

That is good news Roger. I'm glad all is well now. On 2 amps I replaced both transistors. The other amp in the mobile I only replaced the keying transistor. I have used the amp all summer with some long full power keydowns getting it pretty warm and it works like a charm. It is good to have some backup transistors but hopefully we won't encounter this issue again!
I'm happy I was able to help you and your friend out. I have learned so much from the Copper Forum it feels great to put back into it when I can!
I hope this one of a kind Copper Forum stays up and running for a long time to come!73
Kenny
CEF491
Mudduck County
Indiana
The Hotwire Mobile coming soon to a radio near you!
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Captian_radio
Intermediate Member
Username: Captian_radio

Post Number: 481
Registered: 9-2004
Posted on Monday, December 08, 2008 - 1:29 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Maybe this is what happened to my DX250,just quit working,shut it off and turn it on and it lights up preamp works,hit it with some rf from the 158edx and it shuts off,hope its not the finals?
Bob CEF451/VE1CZ
Robert L. Spicer The days of radio are just beginning!
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Captian_radio
Intermediate Member
Username: Captian_radio

Post Number: 483
Registered: 9-2004
Posted on Wednesday, December 10, 2008 - 10:39 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey Pat zerozero where are you , you are my only hope lol.
Bob
Robert L. Spicer The days of radio are just beginning!
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Patzerozero
Senior Member
Username: Patzerozero

Post Number: 4430
Registered: 7-2004


Posted on Wednesday, December 10, 2008 - 4:20 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

q1, 2n4126 keying transistor maybe? have seen the diode that separates q1 from the power switch go too, a 1n4001. what do you mean by 'shuts off', bob? preamp shuts off? could be the preamp transistor, q2, a 2n4125....same deal with q2's diode, d2, a 1n4148.
roger & kenny seemed to have the same problem, could be just a poor choice of transistors on texas stars' part? maybe check the caps & diodes surrounding those 2 transistors for a 'protective upgrade'?
if there was 'no smoke'.....you did it wrong
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Captian_radio
Intermediate Member
Username: Captian_radio

Post Number: 484
Registered: 9-2004
Posted on Wednesday, December 10, 2008 - 8:00 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Tnx Pat, no smoke,weird when I key it it powers down as in shuts off wait for a min or 2 and it comes back on and the preamp works fine when it powers back up.Wiring is good jumpers ok ant ok I will take it inside tomorrow and check it out,really weird.
Bob
Robert L. Spicer The days of radio are just beginning!
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Captian_radio
Intermediate Member
Username: Captian_radio

Post Number: 485
Registered: 9-2004
Posted on Wednesday, December 10, 2008 - 8:34 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ok Pat found the problem,I forgot that I had 2 fuses in the plus line,1 near the battery and 1 at the back of the amp plus the negative also,the 1 near the amp had very high resistance which acted as a thermistor cutting off the supply.
Bob
Robert L. Spicer The days of radio are just beginning!
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Patzerozero
Senior Member
Username: Patzerozero

Post Number: 4434
Registered: 7-2004


Posted on Friday, December 12, 2008 - 9:10 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

guess that's what can happen when you try to prevent a fire at either end of the power cord!

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