It does, but I don't see it burning the 10 ohm resistors unless I'm missing something. But, if there is one, there may be more. Looks like that board needs a good cleaning to reveal any other issues.
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Texas star 667v " bias issues"
- Thread starter Danzik
- Start date
There are other solder splat spots that are questionable around all transistors plus including the fact that Hfe's of each pair(75 & 86) will cause an imbalance at the combiner and it will heat up and eventually get taken out while taking out transistors too. You need to go over the soldering with a fine tooth comb.
Yeah unfortunately, they were all matching until it blew when I applied power last time dang it
Yes, I didn't see that, I will be going over it well now !
I blew out the amp and looked for any other solder particles, everything looked good so I applied power to the unit and no magic smoke this time lol, I manually keyed it and checked voltage at all bases and had around .644 vdc so I am assuming this is good enough? Will keep close eyes on that combiner for awhile and may eventually replace the pills for another matching set
My apologies, been busy with life and haven't been on here much.
I was thinking a short somewhere a bad cap or blob as you've discovered. Looks like you might have found something there already. After removing that blob and if your numbers aren't looking right I would check component values in the circuit. Let us know what you find.
Edit:
I just saw your last post and your findings are what my suspicion was. Glad you caught it and you've got a winner!
Yep, fired it up last night with my cobra 148, seems to be working just the way it is supposed to ! Gonna need to get or make a fan kit for it though gets pretty warm of coarse. Thanks everyone for the help !
I am sure you already know, but keep the drive low, that amp is the hot rod model of Texas Star.
Great work finding the problem.
73
Jeff
Congratulations for sticking with it. The calibrated eyeball can be your most valuable tool, finding the odd solder splash. Been there, done that.
Cooling is most effective with the fan plastered up against the heat sink fins blowing directly onto them. The top component side should not need any air at all, only the heat-sink fins. If the parts on the topside are getting hot you don't need a top-side fan. You need to turn down your drive level.
73
Cooling is most effective with the fan plastered up against the heat sink fins blowing directly onto them. The top component side should not need any air at all, only the heat-sink fins. If the parts on the topside are getting hot you don't need a top-side fan. You need to turn down your drive level.
73