I have some extra nos 2166 driver and 2sc1969 finals and would like to convert my newer galaxy dx959 that has irf520's to them .I know there are 2 diodes d90 and d92 in directly front of mosfets need to be reversed but what else did galaxy change.The reason i would like to do this mod is i had one of the first dx959's made and fully modded it.The radio had more power and swing than this at 13.8 volts which i run at .I have much more info knowledge on modding the old transistors final radio than this chassis with mosfets.Also one thing could someone tell me how to get 5kc slide down 6kc up on this radio i replaced r153 with 12k and it goes from27. 22500 centered to 22620 up and 22420 down.I would like to get to 27.20000 .Thanks alot for any info.
-
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.
converting new dx959 from mosfet to transistor
- Thread starter jef
- Start date
all the mods for the bipolar version works on the mosfet version for out put. it was only changed in the final stages to use a mosfet. the mosfet version if done right will put more out than a 2sc1969. go to Defpoms sight and look at the change over from 1969 to a mosfet and reverse the procedure if you want to put a 1969 in it.
Is there any reason that you MUST change out the final and driver - other than you just have the other parts just laying around?
Think - no; I am sure - that I would just let it be with the MOSFET. Save those 1969's and 2166's for another radio that may really need them someday. The real ones are hard to find and expensive. If you bought them on eBay; then I am sorry to be the one to inform you that they are most likely phonies/counterfeits.
As far as making it slide more, you might try adding a 5.6uH choke between the cathode and ground of D49. And/or get the NTE equivalent varactor diode to replace the stock D49 - IIRC . . .
Think - no; I am sure - that I would just let it be with the MOSFET. Save those 1969's and 2166's for another radio that may really need them someday. The real ones are hard to find and expensive. If you bought them on eBay; then I am sorry to be the one to inform you that they are most likely phonies/counterfeits.
As far as making it slide more, you might try adding a 5.6uH choke between the cathode and ground of D49. And/or get the NTE equivalent varactor diode to replace the stock D49 - IIRC . . .
Slide as in what? What does that do?Is there any reason that you MUST change out the final and driver - other than you just have the other parts just laying around?
Think - no; I am sure - that I would just let it be with the MOSFET. Save those 1969's and 2166's for another radio that may really need them someday. The real ones are hard to find and expensive. If you bought them on eBay; then I am sorry to be the one to inform you that they are most likely phonies/counterfeits.
As far as making it slide more, you might try adding a 5.6uH choke between the cathode and ground of D49. And/or get the NTE equivalent varactor diode to replace the stock D49 - IIRC . . .
"Slide" = amount of frequency shift available with the clarifier. Stock clarifier shift is about 1.2khz lock to lock; adding a 'super-slide diode' will make it shift ~12khz lock to lock. This will make all of the 27.180mHz (example of even freq numbers) freqs available. It can 'slide' between the channels - IOW . . .
use a 477 if your changing it...will do more and take more abuse than a 1969...why change to a older 70 transistor...thats a transistor that wont take much heat...73 de JW
are you talking about a MRF477? if so they are very hard to find and a good one is about $50.00 each and the pin out is different from a 1rf520 or a 2sc2969
my 2sc2166 drivers and 2sc1969finals are original new ive been sitting on them for awhile and thought i would like to put them in my 2011 mosfet dx959 because it doesnt seem to do what my old bipolar final dx959 did for output pep.I will try what is suggested and do appreciate all the info .I also noticed the board is different than the early dx959 in the ic8 audio chip area.Instead of having a 7222ap audio chip its somthing else in these mosfet rigs.what is the part number of the varactor diode i'll jump all over that especially if they might by chance have it at my local radio shack.Thank you greatly for all your guys help!!!!
The MOSFET final in that radio - when properly tuned - will put out between 25-30w. IOW - more than a 1969 will do BTW. Either the radio is not tuned up properly, or your watt meter cannot read real PEP - which is a common thing as many meters cannot do that.
If you are unfamiliar with doing your own radio work and don't have the proper equipment; then I suggest that you send your radio to a shop that will do it all right. Otherwise - proceed at your own risk!
The best way to increase your slide is to jump R114. Doing this, and re-adjusting L20, L21, and L22 will allow you to slide a little more than 10kc in one direction, with about 1kc or so in the other. Good luck!
Also, replacing the original IRF520's in the radio with genuine International Rectifier IRF520N mosfets will improve your output too. After installing the IRF520N's, you'll need to re-adjust the bias voltage at the gates to about 3.7V, and it's always good to do a good TX alignment. I've had radios do in excess of 35W PEP on SSB with a proper alignment, and IRF520N's installed.
~Cheers~
Also, replacing the original IRF520's in the radio with genuine International Rectifier IRF520N mosfets will improve your output too. After installing the IRF520N's, you'll need to re-adjust the bias voltage at the gates to about 3.7V, and it's always good to do a good TX alignment. I've had radios do in excess of 35W PEP on SSB with a proper alignment, and IRF520N's installed.
~Cheers~
My DTB tuned MOSFET 959 does over 30 watts(35 whistle)with my MFJ-971 tuner tweaked just right for the antenna I'm running and that's with either 2 watts deadkey or 4 watts deadkey.
Last edited:
- No one is chatting at the moment.
-
-
dxBot:63Sprint has left the room.
-
dxBot:kennyjames 0151 has left the room.
-
-