Texas Star Amplifier Repair

[nomadradio]

To anybody who stumbles across this thread, that 25-ohm 5-Watt resistor has about 12 Volts DC across it. Should put around one-half Amp through it. 12 Volts times one-half Amp is 6 Watts.

Into a 5-Watt resistor. Nobody checks to see how hot it will be when the amplifier is performing normally. This is the heat it will have to throw when the amplifier is functioning perfectly. Six Watts tends to get a five-Watt resistor pretty toasty.

Pretty much just as hot as when you reach inside trying to pin down a fault.

73

 

[Greg T]

To anybody who stumbles across this thread, that 25-ohm 5-Watt resistor has about 12 Volts DC across it. Should put around one-half Amp through it. 12 Volts times one-half Amp is 6 Watts.

Into a 5-Watt resistor. Nobody checks to see how hot it will be when the amplifier is performing normally. This is the heat it will have to throw when the amplifier is functioning perfectly. Six Watts tends to get a five-Watt resistor pretty toasty.

Pretty much just as hot as when you reach inside trying to pin down a fault.

73

Then why not use a larger resistor? Or maybe parallel two 50 ohm 5 watt resistors?

Am I off track here, or is this a way to reduce the heat and stress?

 

[nomadradio]

Yes, a larger resistor reduces temperature, not "heat" the way engineers use the word. Heat can be expressed as Watts. Six Watts of heat will get a 10-Watt resistor too hot to touch, but a 5-Watt part with half that much surface area will exhibit roughly twice the temperature rise for the same wattage.

Doubling the watt rating from 5 to 10 Watts should cut the rise in temperature in half. The "heat" will be determined by the circuit current and resistance alone.

73

 

[rbentley]

Question concerning the texas star 667v. Is the curcuit board insulated from the chassis? it seems as though i would be grounding all componets of this board by mounting it to the chassis.

 

[rbentley]

where can i get a 667v repaired

 

[Ranch55]

No, the circuit board is not insulated from the chassis..... It is very critical when replacing any of the thru hole components that they not be shoved thru too deep OR they will short to ground ....... causing more problems .......
The 667V is a low drive amplifier with a built in driver section.....
Never was a fan of the 667V amplifier .......

 

[AudioShockwav]

Never was a fan of the 667V amplifier .......

Agree,
The best upgrades for the 667 is to bypass the driver stage and the fuse holders.
They are a hot rod designed for older low drive radios.


73
Jeff

 

[Johnny Waggoner]

Agree,
The best upgrades for the 667 is to bypass the driver stage and the fuse holders.
They are a hot rod designed for older low drive radios.


73
Jeff

Make sure you do the changes on the switches, Might want to watch one of gate keeper's you tube video's. If your using a low drive radio like a 29 leave the driver. If your using a high drive like a stryker or any of the 10m radio's pull it. A power wire upgrade will give you another 100-150 watts. I use the holes and pull the fuses. My fuses are at the Battery. I have seen vehicles actually burn to the ground because the wire got hot shorted then started a electrical fire. I always fuse at the Battery. Shockwave good answer i must say I usually stay silent, but just wanted to agree with what you said. Again good answer.