Nice to see a well designed amplifier. Much better build quality and design then those splatter box junk CB amplifiers. Glad to see all it needed was a shot of cleaner and all the amplifier transistors were ok. Thanks for sharing. Mike
Yeah you right Mike this is a very conservative well designed amp with well working LPF and low IM3 products in two tone test.. Thanks for stepping in. Have a good season holidays . 73
Well done peter it is amazing what dirty contact on a wire wound pot can cause very nice design of an amplifier another success! some of these faults can be hard to find an intermittent can lead to false readings!
Great video once again! I always learn so much watching your videos and listening to the way you explain how the circuits work. Thanks so much. Merry Christmas and 73! de Nick N9SJA
Wow Peter, great video. I learned a lot in this one. I am currently working on a Yeasu FL-7000 500W amp that I have had to Change all 4 Power transistors from the original C2 series to the newer MACom MRF 448 and I am going through the alignment checks and was just ready to check and adjust the bias current. This is my first amp to do any major work on, pretty new at this. This amp had a shorted power transistor that took out the soft start circuit to start with so I took out the transistors and checked them and found one shorted and one open. I sure wish we were closer as I would have brought the Amp to you to repair. Texas to Germany is a long way to ship a 55 lb Amplifier. Keep up the great tutorials, I almost feel like I am in the lab with you. God Bless you, 73 Paul de KR5OG
Thanks for this video Peter and many thanks for all the videos for 2017! Happy Christmas to you and your family and look forward to all the upcoming videos in 2018! 73, Brian EI8EJB
Hallo Peter, habe gerade Dein neuees repair Video gesehen. War wieder sehr interessant für mich !!! Ich wünsche Dir und Deiner Familie ein schönes, erholsames, besinnliches Weihnachtsfest und schöne Feiertage !! Alles Gute vy 73 es 55 de Ralph DB 9 FQ C 31 KM
Hallo Peter, wie immer klasse danke. habe in Dortmund einen Doppelgänger von Dir getroffen. :-D Wünsche schöne ruhige Feiertage, Freue mich auf bald. 73
Ach Du bist das gewesen, sorry ich konnte dich nicht zuordnen. Hättest Du mir deinen YT Namen genannt wäre ich sofort drauf gekommen. Tut mir echt leid. Für Dich und deine Familie ebenfalls schöne Weihnachten und alles Gute. 73
Kein Problem, wollte nicht nerven, ich denke wir laufen uns bestimmt mal wieder über den Weg. Danke für die Wünsche, gute Erholung bis bald mal wieder. 73 Peter
Such a heavy amplifier on the work table just before at the end of the year ..... wow. Please do a video about fixing a Christmas tree string of lights. That would fit at the moment :-D No! ......of course not. It was just a joke ;-) But in some blogs you can read something like that ..... Thanks again for the very interesting video, Peter. I wish you and your family a Merry Christmas 73+55 Bernd
I realize that with a .5 volt tolerance it isn't a big deal, but if the circuit was drawing 300ma before you keyed the amp, shouldn't you have adjusted the bias current to 3.8 amps. Then the transistors would really be getting 3.5amps? Great video, thanks Peter!
The sum of all transistors are drawing 3,5 A or with other words if all are on the same hfe each would consume 3,5A+8=437mA. Thanks for stepping in. 73
I had so many questions to ask, but you answered them in the video. I like that the final stage is like a dead bug design on a tinned PCB. The 4 port switch threw me until I spotted it, with the resistors. I was going to ask how old the amp was but I saw the TIP transistors date code. What else? Oh ya what is the power amp output rating? Can you explain the output stage, from what it looks like it's configure as a push-pull amplifier circuit. Or can it be a Summing Amp where both inputs and output are Summed together? I heard that if you had to change one you would have to change all of them. Why would that be if they are not match pairs or “complementary, or is all the transistor's matching due to Hfe gain to it's partner? And finally what is the resonant frequency of a RLC tank circuit on one of the input stage on the transistor? So many QUESTIONS SO LITTLE TIME, *_Cheers 73_*
Hi Tom, yes a lot of questions...if possible we will try and do some experiments with amplifier design nest year. It is difficult to address al questions here..Anyway thanks for watching 73
ANOTHER GOOD ONE PETER. YA GOTTA LOVE DIRTY WIRE WOUND POTS :-( FROELECHE WEINAUCHSTENS UND GUT NEU JAHR, OBERSCHULE DEUTSCH 1966-1968 :-) MEIN KLASSE NAME WAR FRITZ :-) HAHAHAHA. OJ KØOJ
Yes that is good a good brand of contact cleaner, but i cant seem to find it in the USA, as a result I have been using the De-Ox-It branded products. Does anyone know if the Kontakt products are USA legal/available?
Hm I can't help you not sure if it is available in the US. Have you used Kontakt products before?? May be you find here some infos.. www.kontaktchemie.com/KOC/
Yes, I have used several of the products offered by Kontakt. One of the students I know from university gave me several assorted cans. I asked eric where he obtained them from, and he brought them from home. Thanks for the reply, perhaps I can locate a distributor from the link. Also Thank You for the amazing videos, 73
Two antennas meet on a roof. They fall in love and get married. The wedding was boring, but the reception was great.
T Komoski 😁😁😁
It was one of those "long-distance" relationships right...
Amazing Peter you really know what your doing. I really enjoyed and learned a lot many thanks
I have the TW1000 in the USA No power supply but its the same boards inside. Thanks for the repair and overview of the circuit.
Thanks for watching 73
Nice to see a well designed amplifier. Much better build quality and design then those splatter box junk CB amplifiers. Glad to see all it needed was a shot of cleaner and all the amplifier transistors were ok. Thanks for sharing. Mike
Yeah you right Mike this is a very conservative well designed amp with well working LPF and low IM3 products in two tone test.. Thanks for stepping in. Have a good season holidays . 73
I really appreciate the diagnostic steps and explanations while following the schematic. I always learn a lot from your videos. Thanks.
Glad that you like it Fred! Thanks for watching 73
Good find on that dirty pot Peter. Thanks for sharing this old school solid state amplifier. Merry Christmas my friend.
Thank you Buddy! Have a Merry Christmas with your family my friend 73
love you videos learning all the time from you .....Very clever man
love to hear that
Excellent diagnosis Dr Peter. 😂. You say "only the pot". But the skill is in finding it. Cheers again Peter.
LOL thanks Martin.. All the best 73
Your the best ! Before I even watch the video I'm gonna say it's a regulation issue
Great break down of non mosfet transistor HF amp troubleshooting. I learned a lot, thanks!
TNX Peter...not too many things that could be wrong with that amp and glad it was so simple a fix. Merry Christmas!
Thanks for attending and supporting me over the year Dino! Have a very Merry Christmas 73
I so much look forward to your videos! Always a pleasure to watch!
Glad that you like it Billy. 73
Well done peter it is amazing what dirty contact on a wire wound pot can cause very nice design of an amplifier another success! some of these faults can be hard to find an intermittent can lead to false readings!
You are right John what a dirty pot can cause...Thanks for watching have a good time 73
"1-2-3 OOOO-LAAA"
Love it Peter!
Here, we say "YAYYYY-LOOO RADIO"
I bet OOOO-LAAA translates to the same phrase!
Happy Christmas!
LOL yeah it is the same meaning hehe. Merry Christmas and 73
another fascinating journey you take us on. many thanks & hope you have a happy xmas.
Thank you Rubus and Happy Christmas 73
Great video once again! I always learn so much watching your videos and listening to the way you explain how the circuits work. Thanks so much. Merry Christmas and 73! de Nick N9SJA
Really glad that my videos make sense to you! Thanks for feed back Nicholas 73
Good work, and explained very well, matt
Wow Peter, great video. I learned a lot in this one.
I am currently working on a Yeasu FL-7000 500W amp that I have had to Change all 4 Power transistors from the original C2 series to the newer MACom MRF 448 and I am going through the alignment checks and was just ready to check and adjust the bias current. This is my first amp to do any major work on, pretty new at this. This amp had a shorted power transistor that took out the soft start circuit to start with so I took out the transistors and checked them and found one shorted and one open.
I sure wish we were closer as I would have brought the Amp to you to repair. Texas to Germany is a long way to ship a 55 lb Amplifier.
Keep up the great tutorials, I almost feel like I am in the lab with you.
God Bless you, 73
Paul
de KR5OG
Thank you! Glade that you liked my video! You are on a good way go ahead!
73
Thanks for all the videos throughout 2017. Frohe Weihnachten und ein glückliches neues Jahr für Sie und Ihre Familie. Kind Regards Bob
Thank you Bob! Wish you a Merry Christmas with your family 73
Peter great video fun to see the old girl back in good shape. Have a Merry Christmas to you and yours. Dale
Thank you Dale! Have a Merry Christmas with your family. 73
Peter, gute Arbeit! Frohe Festtage Deiner Familie und Dir aus Köln. Lass von Dir hören!
Hallo Olaf, vielen Dank! Auch für Dich und deine Familie Frohe Weihnachten. Alles Gute 73
Hello Peter!!!...Very nice work, I really enjoy watching your videos!!!
Thank you ! 73
Excellent video Peter, thank you and of course all the best for the New Year..................................Berni
Thank you Berni and of course for you all the best for the coming year as well 73
Awesome repair Peter big thumbs up 👍and merry Christmas to you and your family
Thank you Allan! Merry Christmas to you and yours
Interesting video as always Peter. Thanks & Merry Xmas
Thank you Larry. Hope you had a great Xmas 73
Excellent video.... Thanks for sharing your expertise.....
Thanks for feed-back 73
Thanks for this video Peter and many thanks for all the videos for 2017! Happy Christmas to you and your family and look forward to all the upcoming videos in 2018! 73, Brian EI8EJB
Thanks for stepping in Brian! Merry Christmas to you and yours! 73
Great vid Peter. Merry Christmas to you and your family.
Thanks for stepping in George! Merry Christmas to you and yours!
And many happy returns Peter. 73
Peter it is amazing something like a pot contact can cause many problems
Hallo Peter, habe gerade Dein neuees repair Video gesehen. War wieder sehr interessant für mich !!! Ich wünsche Dir und Deiner Familie ein schönes, erholsames, besinnliches Weihnachtsfest und schöne Feiertage !! Alles Gute vy 73 es 55 de Ralph DB 9 FQ C 31 KM
Vielen Dank Ralph! Ich wünsche Dir und Deiner Familie ebenfalls ein schönes Weihnatsfest. Alle Gute und 73&55
Wow Peter, what a beast!! Great video as always. Frohe Weihnachten mein freund! :)
Merry Christmas my friend have a good time
Always a pleasure to watch your videos! Wishing you and yours a Merry Christmas and Happy New Year! de Dan w4mnc
Thank you Dan! Merry Christmas to you and yours 73
Hallo Peter, wie immer klasse danke. habe in Dortmund einen Doppelgänger von Dir getroffen. :-D Wünsche schöne ruhige Feiertage, Freue mich auf bald. 73
Ach Du bist das gewesen, sorry ich konnte dich nicht zuordnen. Hättest Du mir deinen YT Namen genannt wäre ich sofort drauf gekommen. Tut mir echt leid. Für Dich und deine Familie ebenfalls schöne Weihnachten und alles Gute. 73
Kein Problem, wollte nicht nerven, ich denke wir laufen uns bestimmt mal wieder über den Weg. Danke für die Wünsche, gute Erholung bis bald mal wieder. 73 Peter
Merry Christmas and happy new year.
Also to you Merry Christmas and a happy new year Paolo 73
Great video. Thanks for sharing.
Thanks for watching Tim 73
Such a heavy amplifier on the work table just before at the end of the year ..... wow.
Please do a video about fixing a Christmas tree string of lights. That would fit at the moment :-D
No! ......of course not. It was just a joke ;-)
But in some blogs you can read something like that .....
Thanks again for the very interesting video, Peter.
I wish you and your family a Merry Christmas
73+55 Bernd
LOL yeah we will fix a Christmas tree light lol. Have a very happy Christmas with your family. 73
I realize that with a .5 volt tolerance it isn't a big deal, but if the circuit was drawing 300ma before you keyed the amp, shouldn't you have adjusted the bias current to 3.8 amps. Then the transistors would really be getting 3.5amps? Great video, thanks Peter!
The sum of all transistors are drawing 3,5 A or with other words if all are on the same hfe each would consume 3,5A+8=437mA. Thanks for stepping in. 73
Are any of the 10 ohm resistors burnt or black
I had so many questions to ask, but you answered them in the video. I like that the final stage is like a dead bug design on a tinned PCB. The 4 port switch threw me until I spotted it, with the resistors. I was going to ask how old the amp was but I saw the TIP transistors date code. What else? Oh ya what is the power amp output rating? Can you explain the output stage, from what it looks like it's configure as a push-pull amplifier circuit. Or can it be a Summing Amp where both inputs and output are Summed together? I heard that if you had to change one you would have to change all of them. Why would that be if they are not match pairs or “complementary, or is all the transistor's matching due to Hfe gain to it's partner? And finally what is the resonant frequency of a RLC tank circuit on one of the input stage on the transistor? So many QUESTIONS SO LITTLE TIME, *_Cheers 73_*
Hi Tom, yes a lot of questions...if possible we will try and do some experiments with amplifier design nest year. It is difficult to address al questions here..Anyway thanks for watching 73
Great repair, did you lights dim when the amp is on,, Merry Christmas to you and your family
LOL no the Amp was not able to create a clavilux hehe. Merry Christmas Dennis to you and your family 73
Wow. A fan heater underneath the electronics. Could always use it as a cooking range when the amp fails...
More perfection from the TRX Bench
73 Paul M0BSW
Thank you my friend. 73
Interesting Video Peter thank you Merry Christmas 73 VK6NJP
Thank you James and Merry Christmas 73
"Now we can see what problems dirty pot can cause"
ceramics on the output transformer will be trouble right away.
these should be metal-clad mica or silver mica dipped at least.
Well not so much trouble on this design. The caps are rated for 2KV but in general you are right metal clad micas are the preferred choice..73
O this won't have regulates just diode rectifier...I thought this was ldmos at first
I wondering if you put dialectric grease inside a potentiometer will be any good !!
Yes Pedro after cleaning I always put some lubrication to it.. 73
ANOTHER GOOD ONE PETER. YA GOTTA LOVE DIRTY WIRE WOUND POTS :-( FROELECHE WEINAUCHSTENS UND GUT NEU JAHR, OBERSCHULE DEUTSCH 1966-1968 :-) MEIN KLASSE NAME WAR FRITZ :-) HAHAHAHA. OJ KØOJ
Thank you! Oh Oberschule Deutsch very good and you was called Fritz lol..All the best 73
JA. I PICKED FRITZ.
Datron Transworld still makes HF gear.
We do not often see this brand here in our area.. Thanks for feed-back 73
Yes that is good a good brand of contact cleaner, but i cant seem to find it in the USA, as a result I have been using the De-Ox-It branded products. Does anyone know if the Kontakt products are USA legal/available?
Hm I can't help you not sure if it is available in the US. Have you used Kontakt products before?? May be you find here some infos.. www.kontaktchemie.com/KOC/
Yes, I have used several of the products offered by Kontakt. One of the students I know from university gave me several assorted cans. I asked eric where he obtained them from, and he brought them from home.
Thanks for the reply, perhaps I can locate a distributor from the link.
Also Thank You for the amazing videos, 73
Is this class d
what devices are in this amplifier?
15:50 They are ST 310022. It appears a modern replacement might be MRF454.
"Dirty Pot" can definitely create problems lol
Oh yes LOL
Looks ab-1
Far to Large for that output power.I prefer my ICOM PW-1 at a Kilowatt on all HF & 6 meters bands.
Or ab
It has variable bias ..I believe this is ab biased ...
please, can you give me an email to contact you? Thank you .