Good to see you back Peter!

Hi Peter, I thought that initially that this video could have been the shortest ever as it seemed to work, but there was a bigger picture to view. Nice to see complete logic in your fault finding as usual Peter. Looking forward to the next one and thanks, 73 Brian EI8EJB

I just ordered one of these. Following Peter's method helps me understand how it works. Very easy to follow his explanations, so thank you I enjoyed the video very much.

You’re a good teacher. Thank you.

Thank you for this video, not only did it help me diagnose issues with my own 818 but I also learned a lot regarding circuits in the process!

I would have liked to see the output power on the spectrum analyser when it is increased from 5W to 10W. It would be interesting to see just how much the spurious and harmonic levels rise!

I always learn something from you Peter! I have a FT817 with transmit problems, I think I’ll try to trace it through the same way you did. Welcome back!

Some guys don´t know, what they´re doing; and then they are astonished about the damage. The difference between 5W and 10W is 3dB and only half of an S-unit.

Very good Tech Video, Peter! Enjoyed every time you bring a Radio Back to life... Thank you very much!

Peter, it is the same sad song over and over again..cranking to the max is the solution for everything..;-) It is a QRP TRX, so why...? Buy a 857 if you want more power! Your conclusion is totally right, the high output blow the fuse. I am curios, what the TRX draws in battery mode with this high output mode..maybe there is a big nasty surprise! Thank you for the good work and sharing. And have a look at Paul, he has a great VTVM on his bench, i wish i hat the MIL-version.... Bleibt gesund, Peter! 73 de Olaf DK6KF

Very nice interesting repair. Thanks for the lesson. Enjoyed it as always. That output level is really hard on the PA unit. It's going to get hot.

Nice job Peter in finding the problem.

It great to see you back. If the radio was mine I definitely put it back to 5 watts and can have more air time on it because of the Amp is lower on 5 watts which is ideal it only very little difference fraction on DX between 5 and 10 watts but big difference on the radio it self it best use small external amplifier for HI ground. Great video.

Thanks very much Peter, you are the No 1 tech in Europe 👍

I have a brand new FT-818nd and my power meter shows me almost 8W of power and it's untouched and never opened radio so I am not sure why it's in the specification that it has only 5W despite its giving more. By the way, you have an excellent work approach .. thanks for your tutorials and videos I always watch everyone from start to end. Thanks!

Love this radio! Nice to see it back to life!

Interesting as usual! Thank you for the video Peter. ☺️👍

i do really like your repairs, and i m still going through your videos

Thanks i wonder why they needed to turn up the power when 5 watts can do amazing things with the right antenna. I bet it really drains the internal battery very fast now.

Another TRX Bench Fix! Perfect start to my weekend, thanks!

Many thanks for another marvellous video! I own two FT-817, one from the first batch and one ND. Both running unmodified with 5 watts, giving me a lot of nice cw qsos on the bands without any trouble; the older one since 20 years now. Maybe the 3 dB increase by tuning it to 10 W seems to be significant for their owners, perhaps for FT-8? Anyway, not my problem, mine will stay unmodified. But good to know about that fuse. vy 73 in expectance of many more nice videos!

Nice fix Peter, glad to see you again.

Thank you for the video Peter!

Very interesting, thank you. I will be watching more of your videos.

glad to see you guy...good lesson...easy to understand..good luck

Frustrating when the customer gives false information, Bit of a dilemma that one. Another great video Thanks, 73 de GØUSL

Nice repair to save the yaesu 👍

I had mine in the shop for the same reasons where the radio was overpowered the tech fixed the radio but only the receive came on but not the transmit. I got it back in that condition, he mentioned sending it back to Yaesu for repair but the problem is I am overseas at the moment

Great video Peter! You do such great work and take us through the steps very well. The original complaint of not working on external power reminds me of a repair I had. Took me a while to figure out that the adapter they were using had a longer plastic tip and wouldn't allow the barrel of the connector to make contact with negative (the connector pin is deep). May ask the customer to check their connector. Thanks! - W4XXV

great video, very informative, and explained nice and simple.

Thanks for another really interesting video Peter, I bet the OM doesn't TX for long on battery power with 11 watts output regards Mike

It's the 11 meter mentality at work, always got to get every last watt out of the transmitter. Crank up the voltage, adjust bias, adjust service menu settings, turn every adjustable trimmer to see what happens. POW! Bet you anything it's opened up for full hf tx for 11 meters. They want more drive power for their cheap cb linear. This type of crap will never end. So many nice hf radios ruined by the golden screwdrivers.

Hi Peter. I did a reset on my old FT817ND a few years back and it jumped from 5w up to 10w out. I had to go into the secret menu and lower the power back to 5w.

An old website called dkmods had an extensive list of mods for the 817 many years ago, including a page on increasing the power to 10w, it allowed the circuit protections to work. Whoever said it was possible to increase to 15w but the protections in the circuit were not available. Mine still operates on 5w.

Great video Peter. I have an unmodified 817ND and it works fine as designed. I wonder how many "blown" finals were do to this non recommended modification?

Great work peter. Thank you

And welcome, great to see you also

Thank you for the clear explanation again! Lovely little radio, hope the owner brings the output power to factory. Enjoyed the video! 73

Sounds like zener diode on the switch cutting off the power to the relay is not getting tripped on the battery and when hooked to the power supply the zener does it job and cuts the relay off to the MCU as it is supposed to. Just a guess mind you. Well looks like the voltage to the final stage transistor got blown up by high voltage maybe. Or the voltage regulator to the amplification stage of the RF has been blown up or simply over volted a capacitor somewhere along the line might have happened too. I would check the fuse before the connector for sure. 2.? fuse not a breaker. A breaker can be reset to closed position a fuse must be replaced if blown as we have here. I think what happened to the radio was that whoever owned it kept it keyed up too long and got the fuse overheated and it blew up because the radio os putting out too many watts for the fuse to handle. Replacing the fuse to 3 amps can be devastating to the mosfet transistors in the final stage too. If they are turned up even higher or keyed up too long and burn the mosfets up by too much heat without a proper heatsink. It is better to leave the output power lower and use an amplifier to increase output power so the radio still can run cooler and the amp designed for power increase can be used for increased power output.

Hi there, not having the privilege or access to a spectrum analyser , I'd love to be able to see what kind of spurious signal is being transmitted on a QRP radio like this when the golden screwdriver has been inside a radio like this and is it really tx at 11 watts or is there some harmonics adding to the primary to give that 11 watts? I'm no radio engineer so not 100% sure if that is the case. 73s & Cheers from Australia

I am assuming maybe a small voltage change, increase, would increase the current flow through the fuse even closer to its threshold. therefore it could very well be that the customer had his power supply set to 15 or 16 V.

Thanks for your video Peter, 73s Pasquale IW0HEX

I have a h/b power supply and want to put a over voltage crowbar circuit in just in case. For now I charge a SLA battery. Why buy a 5 Watt radio and then turn it up to 11? It's asking for trouble. If I had the new FT818 I'd be tempted to turn it down to 5 Watts so the internal battery lasts longer and who could tell if you ran 5 Watts or 6 Watts anyway? In my h/b rig I turned the output MOSFET's up and managed even 15 Watts out as an experiment but turned them back down to 5 Watts because they wouldn't last very long. G4GHB

That's what a crow bar is good for. To protect expensive equipment.

I think the owner already tweaked it to 15 W, because it now has a 3 A fuse.

Hi Peter another interesting video Peter you may need to speak to the customer about running the radio on its limit expecting more from it with very little safety margine can the power ampifiers handle the overload would it not put more strain on the componates the little fuse which did blow did protect the radio from serious damage good job it was there you keeping well your friend John

How did the transmitter get “tweaked” to get 9.7 watts output at 12.0 volt input to the finals?

The sad is, i have an FT-817 which had an overvoltage accident due to wrong wirering in my old flat. There was the phase on the N/PE, or maybe only the neutral not connected, so there was potential on the lines due to induction. An Socket tester showed me a failure. At the failure the 817 was connected to an battery which was charged by an "Schaltnetzteil". In the same time i soldered at the wiring for the GND. The soldering iron was connected to the "bad" socket and i heard an electrical strike. (The same happed also, as a laptop and a printer was connected to the broken socket and another one. The owner of the bulding did not send me an electrician until I left this flat.) Thats sad, because i'm not able to find the failure on the pcb. This video triggered me to touch it again. But it is impossible for me to find the root cause. I even did not found out, where the lower supply voltages are made. There shoud be 5V 6 V 9 V made out of the 13.8 V. These lower voltages are definitely missing. The TRX is completely dead, shortly after the incident the display led was on a short time, but later on also this was not working. (Without opening the device) I bought it used, and it looks like somebody was on this TRX before. But it was fully operational before the incident with the, i think 220 V. Due to the fact somebody already worked on the FT a german company shipped the radio back to me without fixing it. They wrote "Bauteile wurden verändert" "Parts have been modified". Maybe this is the frequency extension which the vendor of the prevois owner did. (I don't need/want this extension. "Vom Händler komplett offen") Who can help me here out? It is so sad to have an broken transceiver in the house. The 817 is for me the nicest TRX. If somebody could help me, please ask me for more details, i will try to provide them.

I want a 4,7 Merkelfarad capacitor.

I'd put a 5 amp fuse in and tweak for mo pawah this should have been a 25 watt radio anyway

My 817 stopped tx rx on 2m & 440 but works fine below 6m can't figure out what happened

Thanks for another fine video !!!!

Always more power!!

Thank you so much for your videos Peter! Just wondering, the coaxial cables that are running throughout the inside of this radio, what connectors are on the end of them? I can see two of these cables at 18:29. I've been trying to find a name for them, and make some test leads up so I can finish aligning my FT-757GX. I think they are called a TMP connector, but it doesn't seem quite right. Perhaps, I am performing the procedure wrong, and I should be taking the signal from somewhere else? I'll have to study some more of your videos.

Hi Peter, slightly off topic question but how often do you send your equipment away for calibration? Do you have a rubidium reference for your equipment or perhaps a GPSDO? Would you say the Rohde Schwarz is less accurate than the LP-500 or is there a different signal path into the test set eg: via a PAD and the analyser has an offset? Thanks

Thanks for the video Peter. I wonder what kind of d*mb**ses tweak their QRP PA's to deliver twice the rated output. They have probably never herad of dB:s or understood what they mean.

Nice video as always. I wonder if you connect/use an 10MHz reference on the r&s cms? If yes, do you know what level I can feed in, cannot find any info about it.

Hello Peter, Have a 817nd that I would like to send you but not sure how to get into Uchida with you. Thanks.

👍🏻👍🏻

Peter, I understand the idea of using a current controlled power supply the feed the power amp section but, could you have used the amp meter function of your multimeter and bypassed the chip fuse? You would have seen transmit current draw and output power at the same time. You had already checked the power amp for direct short to ground and found none, so the chance of smoking a component was low, I think. Thanks for the video.

Another great video -- I always enjoy your explanations. Where did you find the parts to repair the radio?

i have a yeasu ft 817 and the lock is on i try to rest and did not work the top button are not working nor vfo nob can you help me

Yes and how many of those running the radio wound up like that are still claiming to be running 5 watts when the brag about who they have worked on 5 watts such a common LIE and from certain class of license holder as well no honour these days

Good video.

Another great repair video Peter. Just wondering what microscope you use for your repair work. The camera has a great zoom too 🙂

Inglês Show, enjoy watching your videos, as it is extremely explanatory and full of information, and I would like to ask you, what would this multimeter be used in this video. I thank you in advance and wish you and your family an excellent weekend. 73 "s to the friend.

Did you have a dummy load? Were you at least in AM or FM?

Hi peter, what kind of spectrum analyzer are you using? is it PC based?

Good work Peter. I have a pair of multimeter lead´s you are using and would like to have the tip's also. What brand are they ? 73 Rodrigo

Couple this setup with a bad SWR antenna and you can blow the finals in record time

It is sort of crazy that Yaesu adds a 2.3A fuse device to protect the finals, then the user tweeks the power to 11W which exceed the 2.3A rating, then the repair shop replaces it with a 3A fuse (in kind consideration of Customer wishes) and later on the finals blow anyway because they are overstressed. The user can then come back to the repair shop for replacing the wrong value fuse after the finals are blown? I would just re-tweek it back to factory setting of 5 watts.

Ich warte mit Spannung auf jedes neue Video von TRX Lab ... Peter hat wieder ganze Arbeit geleistet ... 73 de DL6RDE / AA1KD, Karl-Heinz "Charlie"

As always, nice video, very informative. Thanks for taking the time to do this. 73 de VE2VHE

Watch and learn.

Hallo Peter hab hier einen 817ND der hat ne neue PA Unit bekommen macht aber trotzdem nichts auf denn ganzen Bändern 😔 komm nicht weiter und weis auch nicht was da noch sein kann ❓

It's not a good idea to tweak a radio , that will wreak havoc on amplifiers ...... Certain amps cannot take a lot of wattage on the input ......

I play this at 1.75 times speed so the staccatto language disappears.

Hi Peter! How i contact you ? I don’t find any email address... I have a question about RECAL DANA 9008 deviazion meter ...