Texas Star 667V only produces 300 watts Bird

#386609

I have a Texas Star 667V that only does 300 bird watts into a dummy load with a 14.4vdc supply (from my truck). What could cause this?

I'm using a 2 watt dead key/14 watt swing radio. My meter is a bird 43 with a 1000H slug.

By comparison I have a DX500 that does 400 bird on the same radio, same dummy load, same meter, etc.

Thanks in advance.

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#386617

It's hard to say. The inputs on those 667's are choked back pretty good. You are using a bird 43, does it have a peak kit? I see about 275- 325 average out of the one I have. Pep about 700-750.

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#386618

Yes my Bird 43 has a peak board.

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#386619

Have you pulled top off and looked inside to see if anything burnt?

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#386620

question is this a new box or a box you had and it changed ? Because the new boxes are set up for 10 meters only

#386623

you only have to remove a jumper for the cb band

#386625

Ok the box is used. Yes I pulled the cover. The pulls look fine. I checked the collector and got 14 vdc and the base reads 0.

It was already converted for 11 meter as the cw board was removed.

Someone at some point did change the driver out from the 2290 to an MRF454. They also wired a 4.7k ohm resistor between the side of the front variable resistor VR1 and ran that to the ground, with a capacitor in line.

Then they connected one leg of the input xformer to this resistor/cap and then soldered the other leg of the x former to the ground side of the board.

The original 10 ohm resistor between the SSB delay button and VR1 was replaced with another 4.7 ohm resistor.

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#386629

Sounds like someone's tinkered with amp. No telling at this point

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#386632

Yes someone has been inside. I am trying to make it right again.

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#386633

Need to look at schematic and put back to stock

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#386636

I checked the 667V biasing by checking for resistance between the base of the pill and ground. I read it should be 1.3 ohms. Mine read 0.1-0.2 ohms. The Texas Star guy on YouTube said "this indicates a short". He also said to "not to put RF in." Well that was already done before I got the amp. So I guess I'm going to have to order some 10 ohm 1/2 amp resistors and cross my fingers.

[ Post made via Android ]

#386637

10ohm, 1/2w resistors. if your not getting voltage drop on same, time to lift base of transistor. Use a diode checker and see if transistors are good or bad. If the pill/ transistor is bad. Replacing the 10 ohm resistors won't do any good. Chances are if you have a blown transistor, the resistor across output combiner is toast.

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#386638

Inside pic would help

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#386643

Whoops I meant watt not amp. Thanks for the correction. I'll try and get a pic and figure out how to reduce the size so it doesn't keep telling me the file is too big.

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#386654

From what I gathered reading what you said has been done it seems like someone fried the 2290 and tried choking a 454 so it wouldn't produce the wattage they make, I think there is a 40 watt difference between the two. I would like to see a couple pics as well, get in close as possible to that section of the amp, might see something that will let us know who did the work on it. The next thing I would do is like Crusher said, restore it back to original, you can find the schematic online, replace the 454 with a 2290, check the tank to see if they rewound it, and all the right other components.

3's

Greg

#386656

Agreed, the 454 is not a drop in replacement for a 2290. But to only get 300peak, either it's really padded on input or something is off. I have seen several of the capacitors across transformers toast. I recently redid a Gold box, the 1000pf caps across output transformers were reading 30-40pf. Lol. Someone beat the thing to death.

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#386658

That is what I was thinking, someone tried to "McGyver" the 454 in there because that was all they had. With the variable pot and the added resistance the 454 probably wasn't getting enough voltage to even work. I would say the amp was behind a dual final radio peak to the max, smoked the 2290 and plain and simple the 454 would have smoked the 2879's if it was installed without choking the voltage down.
The TS 667V is a good amp, worth repairing, I like the 500V better and it runs cleaner if not overdriven.

3's

Greg

#386674

Well I'd add pics but Everytime I try it keeps telling me they're too large or they just won't load.

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#386679

I sent you a PM.

3's

Greg

#386697

pic of stratotanker's amp

#386699

pic of stratotanker's amp

#386700

pic of stratotanker's amp

#386701

Okay stratotanker, got them to post, boy that was a workout, need to take a nap, lol.

3's

Greg

#386703

First picture, bottom left side. Yellow combiner. That resistor underneath looks discolored compared to the other input combiner resistor. Looks like it has at least been warm.

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#386777

What about the windings on the stack poles? This has an effect on wattage output right?

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