A Very Very helpful video - My FTdx10 had the same problem and after watching the video I followed the steps in the video, found the same problem and made the same repair with the same result i.e. the radio transmits again, Thanks for the very helpful video Jan
Simple consistent logical and professional. Every time you get to the real root of the issue.. I have learned some skills evey video i watch of yours... Its a pleasure to watch and listen to your narrative as you guide the viewer through the trouble shooting.. Long live TRX lab
hehe - had exactly the same problem with mit FT DX 10 now. Found out the culprit myself, but didn't change the coil -> missing output power. Thanks for the video and all the best for 2025. 73
Great job, Peter. What looks to be a simple job it's actually years of experience condensed in a 20m video. I've seen how un-experienced techs can do more damage before throwing their hands in the air. Obviously the owner was careful with the radio but still the transistor blew, so he must have been devastated at the time. Hams in your area are lucky to have you nearby. We are a special bunch :)
Thank you! I have to agree simply because when I started in electronics i destroyed more that I was able to fix. That is a matter of fact. Nobody should be frustrated if a repair drives you crazy!
OH WOW what a great video and great job repairing it. You explained in detail so nicely! GREAT JOB THANK YOU for this video! From N4TUX Boyd Travis Kingsport, TN.
it looks like that MMG3H21N 100mW amplifier IC needed more heat sink than PC board. if one radio 's IC broke, it often many other radio of same type have same problem. so your video will help many others who own same radio. AG6JU
You are basically right, but there are thousands of this radio type in the field and only very very very few have this issue. That means it is not a design error...
Any time I see this radio I get interested more than usual as it is the big brother of my FT-710. So I want to know what has failed. Well done and I learned from you to test in a load on FM so I do not have to whistle or whatever to get modulation to transmit! Thanks!!!! Ich habe bei der Bundeswehr in Mainz gelebt!
Hi Peter trust you are well peter were did replace the am and coil I did notice a Cap seemed to show signs of leaking near that am or was it a discolour on the PCB greatly explained video
If you are referring to the two 220uF large electrolytic cans, that is glue to secure the components to the board so that vibration does not break the solder joints. --n1bs
For DC a coil or choke is very low resistance, but for radio frequencies it is high resistance. Considering that, means the radio frequencies can't get into the DC supply path.
@@TRXLab That very understandable and the schematic makes a lot more sense. I don't do much with RF except of some tube radio's, so your video's are quite interesting. Dankeschon Peter, gruesse aus die Niederlande.
Hi Peter, Nice to see the PCB layout in the FTdx10 as I have one now. Any reason it was not sent back to Yaesu for repair, unless maybe for the turn around time? I believe there is a 3 year warranty on the FTdx10. 73 WJ3U
Great investigation and repair as always. When describing the amplifier circuit (9:22) we can see the feeding coil connected with two resistors ¼W named R4011 and R4017. About R4011value is clearly 0Ω. The R4011 has ***. Also Yaesu schematics have these 3 stars at various points. At same snapshot (9:22) we can see at left 2 other resistors R4001 and R4003 with no ohmic value but *** instead. Please anyone to explain?
Three asterisks is Yaesu speak for "not installed". If you look on the parts list, you will see there is no entry for these components. There is no entry for R4017 for example. R4017 is in parallel with a 0 ohm "resistor" so it would have no effect anyway. --n1bs
I think one time designer thought it placing some small value resistor to power that MMG3H21N IC amplifier, so they were thinking adding two resistors in parallel to accommodate power dissipation. but, decided to just put short 0 ohm in stead. AG6JU
@@Porco_Utah Yes was my 1st thought, but if you see at same snapshot at your left , you can see a resistive Π network which consists of R4001, R4002 and R4003. Two resistors of three have the ***. SV7GBR
I thought the same thing. I believe that Yaesu has created a design that can overdrive Q4002. If you pull the datasheet, the maximum DC collector current spec is 300mA but there is zero collector current limiting for that class A amplifier. There is an internal biasing network in the Freescale designed component, and maximum RF input is noted at 12 dBm which is 16 mW. If the input from the previous circuitry exceeds that (130 watt RF output for a 100 watt spec would suggest this), then Q4002 might be in an overdriven state. As we know, class A amplifiers have great linearity but suffer from inefficiency. If you trace back the DC path to the 5VDC source, with a zero ohm R value ICC can be greater than maximum allowed. An 18 ohm collector resistor would limit peak DC collector current to under 300mA, but that would lower class A efficiency. I think that Yaesu is relying on drive not exceeding 16 milliwatts and also relying on the internal biasing, but they may have run into end to end RF gain limitations. That MMG3H21N is a SOT-89 which is only a good choice if it isn't overdriven because theta JC isn't the greatest in SOT-89's. In this case, it is spec'd at 38.6 degrees C per watt. Without DC collector current limitation my guess is that this amplifier gets hot when continuously driven (like in FM or FT8 modes). The RF gain of the MMG3H21N is ~20 dB so that part's output with max input would be (12dBm + 20dB = 32dBm) if my calc is correct. If the drive is 6dB over 12dBm specified, then dissipation could easily get to >4 watts. At 50% efficiency that would create 2 watts dissipation which is only 80 degrees C above ambient, not enough to exceed max Tj....unless the DC biasing losses are brought into the equation. The only reasons for two parallel resistor pads would be to be able to adjust DC bias in the case Yaesu engineers wanted to fine tune performance. However, factories never want to have to select resistors so if end to end RF gain was suspect, then perhaps the business decision was made to put zero ohms in the DC path and live with warrantee claims. This is of course conjecture, and without knowing RF drive input it is hard to say how the MMG3H21N failed...but I doubt as if this is a component failure knowing Freescale's (now NXP) quality record has been. I wouldn't just button this one up and say it is repaired without measuring input RF and ICC. Easy to measure with a 1 ohm resistor in the collector circuit and a watt meter on the RF cable just to the left of the Q4002 in question.
You can not always find or know the cause, but if a new radio has issues like this, it is most of the time a part which is not holding it specs. Provided that there is no design error, which we can exclude in this case.
Another great educational video Peter! I purchased a dead FTdx10 for a repair project. But, it must wait until after I complete my family move. For the schematic, are you using the soft copy pdf of the service manual? 73 Chuck ND5CH
Thank you! This is the first video that hints at the problem I may have with my newly purchased dx10. In your opinion is it possible for a brand new one to have this problem right out of the box? The PO meter shows zero power and even deflects a few needle widths left when I transmit. The SWR does the same. I also tried to detect any RF with a tiny SA, and that did not pick up on any signal. Any advice or insight would be much appreciated. Thanks Harold
If you do many Yaesu radios, you might get the feeling that those radios are more often defect than others or that older radios are more reliable, but let me assure you it is not the case.
@@jeffminnick5209 it is really not meant as rhetorical statement. When tube radios and tube TV's were new, these technologies were frequently in repair shops, which we do not see this day's anymore.
Hope all is good your end Peter? Have just watched a war film (sorry, please do not take this wrong bless you, and all modern Germany). The film is Kellys Heroes, but has a lovely theme tune to the film. VERY POSITIVE IF YOU ARE DOWN AND PISSED OFF! WE ALL LOVE YOU THIS END PETER, REGARDLESS OF THE PAST AND NATIONALITY. Keep strong, and safe my dear friend!!! Love from Wayne, Nina and Babs (Barbara) P.S. We are of German ancestry. 💗💗💗💗💗💗💗💗💗💗💗💗💗❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️😚😚😚😚😚😚😚😚🫡🫡🫡🫡🫡🫡🫡🫡🫡
God Bless you Peter and family. We bare no grudges, just wish you all continued good health and stay strong. The past is the past, if Germany is strong again, that is good. If we are all friends again, then no drop of German & British bloody was spilled in vain. 73's Mein Alt Kameraden (?) Thanks Love from Wayne, Barbara & Nina. Full support as always. 👍👍👍👍👍👍👍❤️❤️❤️❤️❤️❤️❌️❌️❌️❌️❌️❌️🫂🫂🫂🫂🫂🫂🫂
Anthony, pls have a look at my comments. I think that there should have been at least 18 ohms in the collector circuit of the MMG3H21N in order to limit DC bias current to the part.
i know some times from servicing new warranty electronics some times the engineering is at fault. strange problems come up that the design has not been thought of. it happens in new designs . take time prove a circuit some times design issues. @@dondonaldson1684
A Very Very helpful video - My FTdx10 had the same problem and after watching the video I followed the steps in the video, found the same problem and made the same repair with the same result i.e. the radio transmits again, Thanks for the very helpful video
Jan
Danke Peter, wir lehrnen jedes mal etwas von deinen werk&wissen !
Das freut mich! Danke
Simple consistent logical and professional. Every time you get to the real root of the issue.. I have learned some skills evey video i watch of yours... Its a pleasure to watch and listen to your narrative as you guide the viewer through the trouble shooting.. Long live TRX lab
Thank you!
A pleasure to watch you work as always Peter.
hehe - had exactly the same problem with mit FT DX 10 now. Found out the culprit myself, but didn't change the coil -> missing output power. Thanks for the video and all the best for 2025. 73
Mehr als eine Sicherung! Bravo!
es ist nicht immer die Sicherung lol
Thanks Peter, great video!
Another good repair, enjoyed the hunt.
Thank you for taking time to put out a new video Peter. Saturday is complete with a beer and watching you do a repair 😊73 LB5JG Asle
Yes, I can agree! Saturday and a nice cold beer is perfect..
@@TRXLab and for me - even more perfect when I can watch you do a repair beside enjoying mein bier. . Have a nice week Peter
Good day sir peter, where are you located. i mean your exact location, i wanna send down my hf radio to you for repair.
Great Video and thank for taking the time to make this
Another fine repair and explanation Peter thank you
Great job, Peter. What looks to be a simple job it's actually years of experience condensed in a 20m video. I've seen how un-experienced techs can do more damage before throwing their hands in the air.
Obviously the owner was careful with the radio but still the transistor blew, so he must have been devastated at the time.
Hams in your area are lucky to have you nearby. We are a special bunch :)
Thank you! I have to agree simply because when I started in electronics i destroyed more that I was able to fix. That is a matter of fact. Nobody should be frustrated if a repair drives you crazy!
Great repair Peter, nice work !!! Nice to see inside PA unit in FTDX-10. 73s Pasquale IW0HEX
Thanks Pasquale, yes it is a very nice build radio.
OH WOW what a great video and great job repairing it. You explained in detail so nicely! GREAT JOB THANK YOU for this video! From N4TUX Boyd Travis Kingsport, TN.
Thank you, glad that you liked it
Thanks Peter for another great video. 73s
It's Saturday matinee time. Thanks again Peter
THank you
thanks Peter, you've just shown me what the inside of my radio looks like, well not that one but the same mode
Nice job my friend.
Thanks for another good video Peter
Deine Videos sind eigentlich unbezahlbar. Danke Peter. 👍👍
LOL, ja da hast Du recht...
Awesome work keep the great repairs and videos coming 73 from Minnesota Kd9dle
Thank you Peter, your videos are a real joy to watch while learning about troubleshooting !!!
This is a relatively new radio and already a faulty part??? Thanks for the video Peter!!!
That is what warranty is for, finding parts which don't fulfill the requirements, since you can't test all parts in mass production.
it looks like that MMG3H21N 100mW amplifier IC needed more heat sink than PC board. if one radio 's IC broke, it often many other radio of same type have same problem. so your video will help many others who own same radio. AG6JU
You are basically right, but there are thousands of this radio type in the field and only very very very few have this issue. That means it is not a design error...
Thank you!
New video, Like, Press Play... Thank you! 👍
A nice repair. Thanks for sharing.
Any time I see this radio I get interested more than usual as it is the big brother of my FT-710. So I want to know what has failed. Well done and I learned from you to test in a load on FM so I do not have to whistle or whatever to get modulation to transmit! Thanks!!!! Ich habe bei der Bundeswehr in Mainz gelebt!
Glad that you liked it! Mainz is nice :-)
Enjoyed riding along. 👍 KØATV
Danke fürs Zusehenlassen. 73
Thanks for watching!
Great job! 👍💯
Hi Peter trust you are well peter were did replace the am and coil I did notice a Cap seemed to show signs of leaking near that am or was it a discolour on the PCB greatly explained video
If you are referring to the two 220uF large electrolytic cans, that is glue to secure the components to the board so that vibration does not break the solder joints. --n1bs
Thank you for this vid Peter. Would you please explain why the transistor is fed with a coil please? Thank you.
For DC a coil or choke is very low resistance, but for radio frequencies it is high resistance. Considering that, means the radio frequencies can't get into the DC supply path.
@@TRXLab That very understandable and the schematic makes a lot more sense. I don't do much with RF except of some tube radio's, so your video's are quite interesting. Dankeschon Peter, gruesse aus die Niederlande.
Hi Peter,
Nice to see the PCB layout in the FTdx10 as I have one now. Any reason it was not sent back to Yaesu for repair, unless maybe for the turn around time? I believe there is a 3 year warranty on the FTdx10. 73 WJ3U
Yes radio is under warranty and that is what warranty is for sorting out parts which are out of spec.
8:01 The 8V Stage is only for Microphon amplifier ? (An Dynamic capsulate run's only up from 7Volt right ? (Ley request)
No, the 8V is needed for several circuits of the radio
What would a repair like that cost ?? Love that radio...
it is warranty
Great investigation and repair as always.
When describing the amplifier circuit (9:22) we can see the feeding coil connected with two resistors ¼W named R4011 and R4017. About R4011value is clearly 0Ω. The R4011 has ***. Also Yaesu schematics have these 3 stars at various points.
At same snapshot (9:22) we can see at left 2 other resistors R4001 and R4003 with no ohmic value but *** instead.
Please anyone to explain?
Three asterisks is Yaesu speak for "not installed". If you look on the parts list, you will see there is no entry for these components. There is no entry for R4017 for example. R4017 is in parallel with a 0 ohm "resistor" so it would have no effect anyway. --n1bs
I think one time designer thought it placing some small value resistor to power that MMG3H21N IC amplifier, so they were thinking adding two resistors in parallel to accommodate power dissipation. but, decided to just put short 0 ohm in stead. AG6JU
@@Porco_Utah Yes was my 1st thought, but if you see at same snapshot at your left , you can see a resistive Π network which consists of R4001, R4002 and R4003. Two resistors of three have the ***. SV7GBR
I thought the same thing. I believe that Yaesu has created a design that can overdrive Q4002. If you pull the datasheet, the maximum DC collector current spec is 300mA but there is zero collector current limiting for that class A amplifier. There is an internal biasing network in the Freescale designed component, and maximum RF input is noted at 12 dBm which is 16 mW. If the input from the previous circuitry exceeds that (130 watt RF output for a 100 watt spec would suggest this), then Q4002 might be in an overdriven state. As we know, class A amplifiers have great linearity but suffer from inefficiency.
If you trace back the DC path to the 5VDC source, with a zero ohm R value ICC can be greater than maximum allowed. An 18 ohm collector resistor would limit peak DC collector current to under 300mA, but that would lower class A efficiency. I think that Yaesu is relying on drive not exceeding 16 milliwatts and also relying on the internal biasing, but they may have run into end to end RF gain limitations. That MMG3H21N is a SOT-89 which is only a good choice if it isn't overdriven because theta JC isn't the greatest in SOT-89's. In this case, it is spec'd at 38.6 degrees C per watt. Without DC collector current limitation my guess is that this amplifier gets hot when continuously driven (like in FM or FT8 modes). The RF gain of the MMG3H21N is ~20 dB so that part's output with max input would be (12dBm + 20dB = 32dBm) if my calc is correct. If the drive is 6dB over 12dBm specified, then dissipation could easily get to >4 watts. At 50% efficiency that would create 2 watts dissipation which is only 80 degrees C above ambient, not enough to exceed max Tj....unless the DC biasing losses are brought into the equation. The only reasons for two parallel resistor pads would be to be able to adjust DC bias in the case Yaesu engineers wanted to fine tune performance. However, factories never want to have to select resistors so if end to end RF gain was suspect, then perhaps the business decision was made to put zero ohms in the DC path and live with warrantee claims. This is of course conjecture, and without knowing RF drive input it is hard to say how the MMG3H21N failed...but I doubt as if this is a component failure knowing Freescale's (now NXP) quality record has been. I wouldn't just button this one up and say it is repaired without measuring input RF and ICC. Easy to measure with a 1 ohm resistor in the collector circuit and a watt meter on the RF cable just to the left of the Q4002 in question.
Very nice and well explained video.
Any insights as to the cause or potential cause?👍
You can not always find or know the cause, but if a new radio has issues like this, it is most of the time a part which is not holding it specs. Provided that there is no design error, which we can exclude in this case.
Another great educational video Peter! I purchased a dead FTdx10 for a repair project. But, it must wait until after I complete my family move.
For the schematic, are you using the soft copy pdf of the service manual?
73 Chuck ND5CH
Good luck with the project! Yes, always using digital PDF on the computer
Well done! Any clues as to what caused the problem? Just a faulty component?
Just a faulty component
Great video. Thanks again and 73's de LA7YKA Einar
Don't you think the extra power causes higher voltage and current to the transistor thus causing the problem in the first place? Just saying. . .
No, not really since the capability is by far not reached...remember the drive for this part comes directly from the FPGA.
That Yaesu is so happy to be fed with an Icom EMC filter. 😂 Sure it wants to transmit again.
LOL
Thank you! This is the first video that hints at the problem I may have with my newly purchased dx10. In your opinion is it possible for a brand new one to have this problem right out of the box? The PO meter shows zero power and even deflects a few needle widths left when I transmit. The SWR does the same. I also tried to detect any RF with a tiny SA, and that did not pick up on any signal. Any advice or insight would be much appreciated. Thanks Harold
Great repair as usual Peter, these new rigs sure don't seem to hold up like the older gear do they?
73 de WD8JM
If you do many Yaesu radios, you might get the feeling that those radios are more often defect than others or that older radios are more reliable, but let me assure you it is not the case.
@@TRXLab more of a rhetorical statement really, my old Drakes just never quit hihi
Stay well 73
@@jeffminnick5209 it is really not meant as rhetorical statement. When tube radios and tube TV's were new, these technologies were frequently in repair shops, which we do not see this day's anymore.
@@TRXLab indeed, all things being equal I still prefer kenwood and icom though... have a great day Peter, nice to chat!!!
Looks like a almost new radio with the screen protection still on.
You are right, it is new and in warranty
Congratulation for this extraordinary work you are doing.thanck you.Why don.t you open a special preparing school for this kind of reparations¿
Thank you! Well, it is all about time....
I have changed driver transistor in this some times RD04
Something for experienced folks only!
@@TRXLab Yes! It is my work to keep such equipments up and running again, like you do 🙂
Hope all is good your end Peter? Have just watched a war film (sorry, please do not take this wrong bless you, and all modern Germany). The film is Kellys Heroes, but has a lovely theme tune to the film. VERY POSITIVE IF YOU ARE DOWN AND PISSED OFF!
WE ALL LOVE YOU THIS END PETER, REGARDLESS OF THE PAST AND NATIONALITY.
Keep strong, and safe my dear friend!!!
Love from Wayne, Nina and Babs (Barbara)
P.S. We are of German ancestry.
💗💗💗💗💗💗💗💗💗💗💗💗💗❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️😚😚😚😚😚😚😚😚🫡🫡🫡🫡🫡🫡🫡🫡🫡
All good here. The upside of the story is this country is completely different to what it was...
God Bless you Peter and family. We bare no grudges, just wish you all continued good health and stay strong. The past is the past, if Germany is strong again, that is good. If we are all friends again, then no drop of German & British bloody was spilled in vain.
73's Mein Alt Kameraden (?)
Thanks
Love from Wayne, Barbara & Nina.
Full support as always.
👍👍👍👍👍👍👍❤️❤️❤️❤️❤️❤️❌️❌️❌️❌️❌️❌️🫂🫂🫂🫂🫂🫂🫂
I was just wondering why i haven't seen a video in a while
Not clear to me what you mean??
Wish you lived in the USA.
130w is "normal" for an ftdx10???
Not necessarily normal, but the radios are adjusted that way from factory. I would always recommend reducing the output power to approximately 80-90W
that's a weird defect, at that position and power level that MMIC should have been indestructible.
You are right and if the part is fulfilling its specs it is the normal behavior.
brand new radios going dead, sad affair
That happens from time to time, but therefore we have warranty!
Anthony, pls have a look at my comments. I think that there should have been at least 18 ohms in the collector circuit of the MMG3H21N in order to limit DC bias current to the part.
i know some times from servicing new warranty electronics some times the engineering is at fault. strange problems come up that the design has not been thought of. it happens in new designs . take time prove a circuit some times design issues. @@dondonaldson1684
I have a FTDX101MP warranty repair was rejected unless I pay $1,570-$2,000
Due Due to Stray RF
Tim Factor is a Thief
Contact yaesu Japan
@@TRXLab
Roger that
Thanks