Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Looking for 2SC2312 finals

Turbogus

Turbogus

Member
Oct 17, 2010
31
0
16
62
Hi folks,

This may be beyond any novice repair but I got this radio for free so if it's within my capability I'd like to see if I can get this bugger working.
The radio is a Uniden Pro520XL mfg in Taiwan. :sneaky2:The Ch. lights work properly and I can hear the familiar "pbt" when keying up, but no signal with a known good antenna within proximity of 50 ft of the monitoring rig.
I've taken the case apart and cursor look at the pcb there's no sign of burnt circuits or broken connections.

My interest in this radio is that it fits in a moulded console in the ceiling of his van. This 520 has a conventional 4 pin mic connection that is desireable, His 510 he kaputted by thinking the mic connection was a twist type when actually it was a 6 pin half moon type.

5778688790_bd1f834210_z.jpg


From another forum it was supposed that the final may have gone kaput, however the 2SC2312 is no longer available (except for the fakes) what can I do?

Thanks and a lift of the lynch lid for your help.
 

Going by your picture the original transistor was a mitsubishi 2sc2166, you could try a sanyo 2sc2078 which are still around and cheaper than the 2sc2166's.i believe the newer 520 and european president derivatives use the 2sc2078 from the factory.
 
the guy who made that video is Mark, weazle66 from uk e bay, if you have any doubts buy your transistors from him, i can assure you he doesn't sell fakes when he has originals and the copies from eleflow he sells work too. i have dealt with Mark a few times and his honesty/service is first class.he should have original sanyo 2sc2078's as thats where i last got them myself.

if not try the eleflow 2sc2166, i doubt you'll see any discernible difference between them anyway,except maybe price.

if you take a look at your radios final 2sc2166 transistor, you'll notice between the 3 leads there is 2 small plastic triangle shapes that are part of the casing, fakes never have those, all original mitsubishi's do have them, the c on the c2166 on mitsubishi transitors is always elongated, like an oval with a part cut out, whereas the fakes generally have the letter c that looks more like a circle with a bit cut out. the amount of fakes out there is frightening, but they can be avoided, a good indicator of fakes i've noticed is the retailers don't show a picture of the actual device or its blurred, for obvious reasons.

incidentally you have more chance of turning up 2sc2312 or 2sc1969 fakes than any other, as they are used on the premium ssb radios therefore making fake ones is more profitable as these radios are higher powered and those transistors are higher powered/higher priced than the 2sc2078/2sc2166.

you can also use the 2sc2078 as a driver transistor in radios that previously used a 2sc2166 driver.
 
Yeppirs, I've been in contact with Mark and he's a straight shooter all right! (y)

Given the results of testing this little 520, the trouble may not be with the final after all. (there was 0 audio on the receiving unit and no meter activity on the transmitting 520, I couldn't check signal strength inbound as I was using my P.A. at the bus station here to monitor audio)

So, if the trouble is not the final,
5787973796_ec7c3cd8f3_z.jpg
(after wrestling it to the ground)


what else should I, a novice look at?
 
Last edited:
From a couple of other folks I've heard from, I can go and try to replace the 2166 and see if there's any improvement. Logically, if not pull the transistor as a spare and just get another radio as the test gear and procedures are beyond my understanding when it comes to IF mixer or TX voltage only supply problem that Mark suspects
 
Okay, final post on this radio. I successfully replaced the final (2166) and testing I now get faint white noise through the speaker (static) but the same transimit symptoms as before. All lights are on, when I key up the red TX light is on but no response from the meter and no audible transmission. I'm not dissapointed really, as this is my first project of this kind and I have a factory refurb unit comin' in for my friend. I am glad that I now have limited experience in removal of transistor from PCB, desoldering and re soldering intricate transistor contacts. Thanks to all and especially Mark, in this thread for their patient responses.
 
Turbogus said:
Okay, final post on this radio. I successfully replaced the final (2166) and testing I now get faint white noise through the speaker (static) but the same transimit symptoms as before. All lights are on, when I key up the red TX light is on but no response from the meter and no audible transmission. I'm not dissapointed really, as this is my first project of this kind and I have a factory refurb unit comin' in for my friend. I am glad that I now have limited experience in removal of transistor from PCB, desoldering and re soldering intricate transistor contacts. Thanks to all and especially Mark, in this thread for their patient responses.
Click to expand...

sounds like the radio may need an rf/if alignment and possibly the vco or mixer looked at. sounds like someones definately been in there twiddling things.

feint noise through speaker could be due to a blown audio ic.
 
rf/if alignment and possibly the vco or mixer elements are beyond my knowledge as yet. Perhaps at some point I'll study such in my limited free time.
Got the factory refurb unit installed yesterday and got the SWR to 1.5, next weekend going to attach the ground strap and see if I can get it a little lower.
 

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom
      Back