Re: Hi all, newbie with a ?

Well Dave, You sound like you have a moderate amount of knowledge and I assume that you tried to locate a schematic. Draw the circuit from the pc board traces. Look at the holes where the transistor was and draw a circuit as you follow the traces. Will your "guessed" transistor fit this circuit? Good Luck, Tom

I hope this is the right group for the question I have to post. If not,

let

me know, and I will skeedaddle. > > I am trying to repair a 20-year-old Uniden handheld CB transceiver, which
I
*think* has the finals blown. My neighbor picks up no signal when I > transmit to him from about 50 feet away, but my shortwave radio picks up

the

transmission from only a few feet away. I can't find my wattmeter as most > of my electronic stuff is still packed and in storage (we recently had to > abandon house for two months.) I do have my oscilloscope and DMM, plus a > few other odds and ends that never got packed. I *think* I have located

the

transistor that acts as the final amplifier and have removed it from the > circuit. It is a TO220 style, and the only markings on it are "2029C/1". > Am I safe in assuming that this is basically a 2SC2029, or some other > compatible? My only clues to the identity of this puppy are its physical > location on the board (near the antenna connection) and the fact that it

is

surrounded by several small (3/16" x 5/16") coils. I do*not* want to just > stick another transistor in there in its place and try to transmit, but I

am

not sure of where to start with my analysis (it's been a long time since > I've done anything quite like this.) Oh, one more thing, this CB has a > seven-inch long alluminum heatsink running the length of the PC board, and > this transistor and one IC (at the other end) are the only things on it

(in

other words, there are no other power transistors in the circuit). > > Should I proceed with a 2SC2029 or an equivelant? What do others think?
I
value your opinions, and any help would be appreciated. > > Thanks, > > Dave > snipped-for-privacy@hotmail.com > > > > >
Reply to
Tom Biasi
Loading thread data ...

Hello Tom,

Thanks for the reply. Yes, I tried to find a Sams Photofact on this guy, but they don't seem to do much with Uniden products. From what I can tell the transistor that the local parts distributer recommended should fit nicely. It is a 5W final RF output NPN transistor, TO220 style, and the voltage parameters ought to work (I think). They had two and I bought them both. Put one in and tried it out with my neighbor listening on his unit. He said I came through loud and clear. Then I tried to hook it up to my watttmeter and it only regisered about 150 mW. SWR's were HIGH. Suspecting I blew the new transistor I pulled it out and replaced it with the second spare. Will probably not mess with it much more if it seems to work again. Or i may take it to the local shop just down I-10 and ask them to check it out for me to see if it's putting out a decent signal. I still can't seem to get any response to a radio check, but that might be due to my location, don't know. Oh well, It never worked anyway.

Take it easy...

Dave snipped-for-privacy@hotmail.com

you

which

most

to

a

"2029C/1".

physical

just

I

and

Reply to
Dave

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.