Project X (X9)

[Eldorado828]

The specimen is an x9 that was donated for parts. I've been chasing my tail with this one. I resolve one issue then another comes about either immediately or after a few days. I'll be posting as I go along with hopes that the great wwdx minds can assist me.

For starters can someone help me identify this part mounted to the of the chassis.

 

[Xracerx13]

8 volt regulator

 

[Eldorado828]

8 volt regulator

I'm looking to figure out the actual part used by ranger. 8 volts how many amps?

 

[Xracerx13]

All i can find on that part number online says 8V 1.7Amps which I'm sure you found too.

 

[SuperLid]

7808 8v 1.5A

 

[Eldorado828]

7808 8v 1.5A

Thank you @SuperLid

I'm having issues with the backlighting and going to check it tonight.

So I replaced all the mosfets, set bias, dk and all that good stuff and it did really well Am talking local a coupleof days. Then...

All of a sudden I went out to turn it on and the frequency display goes all over the place and the display led's are really dim at the same time. I learned that if I either flip the channel up one or change the band it stabilizes and goes back to normal. The display led's get back to full illumination if it sets for a little while. All these conditions started at the same time. This radio had a few issues to start with and has snowballed after the initial repair.

This was supposed to be a parts radio but it turned into an educational project.

 

[nomadradio]

If you can put a 'scope probe on the output pin (right hand) and watch the output voltage, this would reveal if it's being unstable.

The all-plastic version of this regulator used to be harder to find than the old version with the metal tab. It simplifies installation, but has a higher risk of overheating.

73

 

[Eldorado828]

Well after some more troubleshooting last night I've concluded that the regulator is not the problem. I notice that by connecting only the power in and ground and removing the +out from the header I get 8 volts out. Now if I probe the empty pin where the power out goes back into the pcb I have voltage leaking in from somewhere else. I'm suspecting a bad smd cap somewhere in that pcb causing things to go crazy when I install the wire back into the header and plug it in. I'm only seeing 4.2 volts on that board so there isn't enough voltage make everything work right.

Causing very dim displays and frequency going all over the place.

No schematic really makes it a chore.

This radio has some issues..

 

[Xracerx13]

7808 8v 1.5A

Thank you @SuperLid

You initially asked for specs on the regulator you posted a picture of. I told you it was an 8V regulator @ 1.7Amps. Those are the correct specs for a 17808T 8V regulator. The part number is right on the device. Even though as you say, the regulator is not your problem, you chose to thank someone else for giving you specs on a common 7808 regulator. Completely different than your regulator pictured.
You made me feel like I wasted my time responding to your question, and on top of that made it seem to me like both my answers were not good enough for you. I don't give out incorrect information. I went and found the spec sheet for it and gave you a better answer in my second post. Its what I do as a real tech with over 40 years experience at home and in the work field. Maybe you overlooked my responses. I don't know how, but at least give credit where credit is due.

 

[nomadradio]

Somebody (else) needs to trace down the schematic for this circuit board, and produce a placement diagram.

This was how Howard Sams did it in the 60s and 70s. Called their method "Circuitrace"(tm).

73

 

[SuperLid]

You initially asked for specs on the regulator you posted a picture of. I told you it was an 8V regulator @ 1.7Amps. Those are the correct specs for a 17808T 8V regulator. The part number is right on the device. Even though as you say, the regulator is not your problem, you chose to thank someone else for giving you specs on a common 7808 regulator. Completely different than your regulator pictured.
You made me feel like I wasted my time responding to your question, and on top of that made it seem to me like both my answers were not good enough for you. I don't give out incorrect information. I went and found the spec sheet for it and gave you a better answer in my second post. Its what I do as a real tech with over 40 years experience at home and in the work field. Maybe you overlooked my responses. I don't know how, but at least give credit where credit is due.

The part pictured, is a 1A plastic device. So, in your 40 years of "real" tech experience, maybe you should know, that a standard 3 terminal regulator will work. Possibly better than the one in the radio. But, maybe I'm just a dumb YouTube tech, that gives out bad information.

 

[Xracerx13]

For starters can someone help me identify this part mounted to the of the chassis.

The part pictured, is a 1A plastic device. So, in your 40 years of "real" tech experience, maybe you should know, that a standard 3 terminal regulator will work. Possibly better than the one in the radio. But, maybe I'm just a dumb YouTube tech, that gives out bad information.

I can see clearly the original is all plastic. I do know that a standard 7808 1.5A made with metal will most likely work, but at least replace it with the same 1.7A amp rating or better.
All I did was answer the OP's question correctly and got no thanks. Thats it! Nothing more nothing less.

 

[SuperLid]

I can see clearly the original is all plastic. I do know that a standard 7808 1.5A made with metal will most likely work, but at least replace it with the same 1.7A amp rating or better.
All I did was answer the OP's question correctly and got no thanks. Thats it! Nothing more nothing less.

The plastic part is rated at 1A. I don't know what datasheet you looked at, but it's wrong. Since you feel slighted and had to flex your 40 years of "real tech" experience, I'll say, thanks for your input! Atta boy! I hope you feel better now.

 

[Xracerx13]

The plastic part is rated at 1A. I don't know what datasheet you looked at, but it's wrong. Since you feel slighted and had to flex your 40 years of "real tech" experience, I'll say, thanks for your input! Atta boy! I hope you feel better now.

I found my reasoning.
Its rated at 1A continuous with a peak output of 1.7A.
https://pdf1.alldatasheet.net/datasheet-pdf/view-marking/130320/ROHM/BA17808T.html ...page 2

Atta boy! to you for making me look deeper at the data sheet!