EURO 3900 IRF520 conversion
EURO 3900 IRF520 conversion
my euro3900 had a 2sc1969 final that went poop.... i was wondering if anyone could help with info to convert it to an irf520.
it has two trannys mounted to the rear heatsink, one was a 1969 and....well i don't remember what the other was, so i'm not sure if it has dual or single finals. each transistor has a bias adjustment pot.
the reason i'm confused about it being dual or single final is because it also has a 2sc2314 (I think) driver installed on the PCB just in front of the rear mounted trannys.
so, how could i stick a 520 in there
it has two trannys mounted to the rear heatsink, one was a 1969 and....well i don't remember what the other was, so i'm not sure if it has dual or single finals. each transistor has a bias adjustment pot.
the reason i'm confused about it being dual or single final is because it also has a 2sc2314 (I think) driver installed on the PCB just in front of the rear mounted trannys.
so, how could i stick a 520 in there
Cobra 29/NW/ST
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
EURO 3900 IRF520 conversion
if anyone needs the PCB number, I'll crack the case back open and find it. thanks.
Cobra 29/NW/ST
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
EURO 3900 IRF520 conversion
When ask for any help it is always best to give the PCB number.
If the radio is working ok, I would stay with the bipolar transistors as long as you can, it makes no sense just changing them just to gain a few extra watts.
I may find the info you need is on
http://www.cbtricks.com/miscellaneous/f ... /index.htm
If the radio is working ok, I would stay with the bipolar transistors as long as you can, it makes no sense just changing them just to gain a few extra watts.
I may find the info you need is on
http://www.cbtricks.com/miscellaneous/f ... /index.htm
Rick.
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EURO 3900 IRF520 conversion
Good advice keep with stock tran as long as you can.
James.
James.
EURO 3900 IRF520 conversion
well, thing is... the tranny is already toast. I would really like to find a 1969 replacement, but aren't they discontinued? If there are any left out there, does anyone know where I could find a REAL one? Or at least a suitable replacement?
I really don't want to hack up this radio!
I really don't want to hack up this radio!
Cobra 29/NW/ST
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
EURO 3900 IRF520 conversion
They are discontinued, and, if you do find them, they are quite expensive, I would not hesitate going with a mosfet at this time, they work really well.
EURO 3900 IRF520 conversion
I found this on the net: Workman 1969X CB20W 2SC1969 Replacement..... It says that it is meant to be a drop in replacement for the 1969 and will work fine with a properly adjusted bias voltage.
I also found some genuine 2sc2312's for 10 bucks.
I'm just wondering if anyone has tried any of these and if they will work. I have been having the worse kind of luck finding a genuine 2sc1969.
Thanks...
I also found some genuine 2sc2312's for 10 bucks.
I'm just wondering if anyone has tried any of these and if they will work. I have been having the worse kind of luck finding a genuine 2sc1969.
Thanks...
Cobra 29/NW/ST
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
EURO 3900 IRF520 conversion
CB20Ws are garbage, I would take the 2312's.
EURO 3900 IRF520 conversion
Thanks guys for all the help. I think I'll try the 2312's out.
Cobra 29/NW/ST
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
Cobra 29 LTD
Realistic trc-52
Realistic trc-217
EURO 3900 IRF520 conversion
All new Superstar 3900 radios(with the blue s meter and channel readout) are using 2 x irf520 mosfets for the output. My 3900 does 10 watts am/fm and 20 pep on ssb. Will these handle ok at these ratings? I always wondered why Mitsubishi discontinued the good old 2sc1969. They were very robust.
Re: EURO 3900 IRF520 conversion
Everybody keeps saying the 2sc1969 is hard to find and expensive. buy them here.http://www.rfparts.com/transistors_2SC. ... 9115918011
If they are out of stock I have some I will sell for 10 bucks.
If they are out of stock I have some I will sell for 10 bucks.