I built my amp a few weeks ago and it was a great kit to build. I think I had the same mounting issues you did, your video made me laugh (empathy). I appreciate QRP-Labs for making the kit, mine was great on initial power up and really didn't need any fine tuning.
Guys I'm with you 100%. I laughed my head off watching the video. I designed the kit. I designed the enclosure. I wrote the assembly manual. Yet, when actually assembling one for validating the instructions and taking photos for the manual, guess what? I made all the same mistakes. Screws in the wrong holes, IRF510 wouldn't slide by, pads fell off the box lid, etc. I had to do it all again. TWICE! So yes: follow the manual to the LETTER! Then it will all go together properly. 73 Hans G0UPL qrp-labs.com
Thanks for posting the video! I have been considering purchasing the amplifier as a fun little project to go along with the QCX that I built last year. 73 de AD0WE
Built this amp this past weekend in three hours to work with my Norcal 40a. The Norcal doesn't provide 5-v on Transmit, but does have 8-v on Tx at U2 Pin 8. This works fine with no other mods and with 1.7-w drive, the amp puts out 20-watts with just a 13.8-V Power Supply. Dave - w6nfu
Hans makes some nice kits. We're all still waiting on the QSX kit... coming up on two years now. While I'm waiting, I'm getting a 40m Phaser for a solar powered 40m JS8 message server using a dedicated Raspberry Pi at my QTH. As you mentioned in the video, the QRP Labs amplifier could be a very good option for vehicular use where power isn't as limited and a compromise antenna such as a coil loaded HamStick is being used. That would allow the amp and antenna to remain in the vehicle with the amp hidden under the seat or under the dash, and a portable transceiver could be quickly plugged in as desired. That would be a great option for the QSX when it's finally available if you'd like an all band all mode portable transceiver, or a Phaser with a Pi or small netbook could be used for digital modes, including my favorite, JS8.
@@RadioPrepper - I'm talking myself into two 40m Phaser transceivers - one for the JS8 message server at home and another for the JS8 go box, either backpack portable or mobile in my truck. For over a decade, I've dreamed of my Canned Ham, simple to use very portable long range EmComm transceiver. I never developed it because it would have been a huge project, but we're getting close with JS8 and the available transceiver kits such as Phaser or QSX. Ideally, it would have a resonant end fed 40m/80m wire antenna and could be used on either band depending on band conditions, with standard and custom (local group) frequencies, possibly with something similar to Automatic Link Enabling. Low antenna for NVIS regional comms or raise the antenna for DX. It wouldn't take much work to redo the Phaser to have filters that could be software switched between 40m and 80m. Ditto for the QSX, but it'll have even more band options. Make it easy to interface to a netbook PC or Raspberry Pi. There could even be an ultralight microcontroller version with a waterproof silicone keyboard and dot matrix LCD.
I've got that for 40m, to go with my QCX. I'm just finishing up the Midnight Design Solutions' Phaser transceiver, so I'll be jumping on the QCX amp next.
From Amazon a DC to DC Step Up 30-V 10-A Regulator was added in line with my Astron 20-Amp PS to boost the voltage up to 20-volts at 10-amps for the QRP-Labs 50-watt Amp. Now the Amp is putting out an honest 51-watts when driven by the 1.7-watt Norcal 40a. What a pleasure to use. w6nfu
Good to see you screw up like the rest of us. I've tried kit building but it never works out. Somewhere during the build the smoke gets out and that's the end. Oh Well, the fun is in the trying. Enjoyed the video, more are expected, please.
I strongly recommend putting in a 470 R resistor in the the control line to the keying. This is particularly important in early revision Qcx Minis with the substandard 5V regulator. If you hot plug the control line then you risk blowing up the driver Qcx sometimes even if it is not keyed. Essentially you put the 5V regulator in pass through mode and the 14 V toasts most of the sensitive parts of the Mini, in particular the 328 Atmel. This extra resistor limits current and prevents Bad Things Happening. Possibly later revisions of the mini are proofed against this. Early versions are easily killed via a hot plugging event. TEF
@@RadioPrepper Don't think about it.. just do it.. put it in the cable and label the cable as NO SUBSTITUTES . A sad story follows - check the version that starts in French.
Did you ever get your slop bucket 2 going ? I have one of those kits from Steve but I still have not put it together yet. I built one of his mtr3b original kits it's one of my favorite radio's.
I just received this kit for my 40 meter qcx a couple of days ago. Have you used the amp yet? How did it do? I watch all your English videos. Thanks for putting them together I always learn something.
Very Good Video I am finishing up my 50 watt amp and waiting for the Cabient for it, tho we are in a Convid 19 Health stage, shipping is slow or not at all on imports. Your QCX unit cabient where you get it ? 73's Dale
I love your videos! especially when they are assemblies, I would like to purchase this kit, I have a 4watts homebrew qrp and I would like to increase his power, I will take a look at the qrp-labs website and see if they ship to Brazil, it would be great to assemble a kit as well done like that. 73 from your hamfriend from Brasil PY2NQC !
The -6 cores will work on 80 meters, but you will need more wire. While the recommended frequency range of the -6 cores doesn't go as low as 3.5 mhz, in certain applications this really doesn't matter. For band pass filters, the -6 cores might even give better results on 80 than the -2 cores, ask PA3AKE why.
Hi Gil, again a nice video, well done! I have a QCX-40m still without a enclosure. Which model Hammond box did you use? The board seems to fit nicely. 72, PA0CMU
@@RadioPrepper there are some that contain products you could react to, if you haven't had any reactions you are probably ok. It is recommended to use gloves if you have to apply it with a finger. Search for "thermal paste carcinogen" for info.
Merci pour cette video en francais. Y a t il possibilité de se servir d'un Baofeng uv5r comme base avec une antenne extérieur type filaire, scoubidou,..etc ? Merci
FYI I haven't added heatsink compound on any of mine. In fact the improvement it makes is minor. The IRF510 is not a particularly high power device. It is cheap and it is common, and it makes a great 50W HF amp. That's why I used it. The thermal resistance is made up of 1) semiconductor junction to TO220 tab 2) TO220 to silicone insulator tab 3) silicone insulator tab 4) silicone insulator tab to box 5) box metal 6) box external to heatsink. By FAR the dominant term is the semiconductor junction to TO220 tab thermal resistance. This is inside the IRF510 device and you can't do anything about it. Heatsink compound between box lid and heatsink has negligible benefit as the contact area is large. Heatsink compound between IRF510 tab and the silicone pad makes very little improvement because the main thermal resistance (at least by an order of magnitude) is the semiconductor junction to the IRF510 tab. Heatsink compound does no harm but neither, at these power levels and with these devices, does it make particularly much difference. 73 Hans G0UPL qrp-labs.com
Depends on which one... Maybe start with a Pixie or a Rock-Mite (The real one, not a Chinese knock-offs), then maybe an amp. Honestly though, 5W CW or 20W SSB is enough, no need for an amp...
hey Prepper when you do a dill out like that you need to make up a cardboard chute to go under and tape it in. THen you have someone with a vaccy cleaner sucking at the top to take off the swarf while you drill. This is a known industrial technique and it works. TE FIDLER
FYI Amplifier Class is a matter of how it is biased. If you increase the bias potentiometer to around 1/4 A idle current, the transistors will operate in their linear region and it would work for SSB. Efficiency and heat dissipation will be higher so watch out for high temperature rise. Though SSB isn't continuous full power anyway - the average power will depend on what level of speech processing you have but I'd keep it not more than 25W average. This would be experimental - I have not tested it myself and do not know how good the linearity is (and hence IMD3 performance). 73 Hans G0UPL qrp-labs.com
Whenever u put out a new video, I know it will be interesting, and will learn something every time, thx Gil 73s
Thanks. I do too ;-)
I just thought the same. Very good presentations explained in a gentle way.
Thanks! I just build the 50W Amp. Had the same problemas with the transistors. Hard, but given time and patience, it will go!
I built my amp a few weeks ago and it was a great kit to build. I think I had the same mounting issues you did, your video made me laugh (empathy). I appreciate QRP-Labs for making the kit, mine was great on initial power up and really didn't need any fine tuning.
Yep, very simple and just one adjustment!
Guys I'm with you 100%. I laughed my head off watching the video. I designed the kit. I designed the enclosure. I wrote the assembly manual. Yet, when actually assembling one for validating the instructions and taking photos for the manual, guess what? I made all the same mistakes. Screws in the wrong holes, IRF510 wouldn't slide by, pads fell off the box lid, etc. I had to do it all again. TWICE!
So yes: follow the manual to the LETTER! Then it will all go together properly.
73 Hans G0UPL
qrp-labs.com
An excellent “pro tip” with the drill bit for the pad placement.
Thanks for posting the video! I have been considering purchasing the amplifier as a fun little project to go along with the QCX that I built last year. 73 de AD0WE
You did a fantastic job of assembling that.
Thanks!
Built this amp this past weekend in three hours to work with my Norcal 40a. The Norcal doesn't provide 5-v on Transmit, but does have 8-v on Tx at U2 Pin 8. This works fine with no other mods and with 1.7-w drive, the amp puts out 20-watts with just a 13.8-V Power Supply. Dave - w6nfu
Good news, since I am building a NorCal 40!
Tnx Gil, excellent vid again! For that low cost, it is on my list for my 20m QCX.....73 GW4OKT
Great video. Happy to have found you. Definitely subscribing.
Hans makes some nice kits. We're all still waiting on the QSX kit... coming up on two years now. While I'm waiting, I'm getting a 40m Phaser for a solar powered 40m JS8 message server using a dedicated Raspberry Pi at my QTH. As you mentioned in the video, the QRP Labs amplifier could be a very good option for vehicular use where power isn't as limited and a compromise antenna such as a coil loaded HamStick is being used. That would allow the amp and antenna to remain in the vehicle with the amp hidden under the seat or under the dash, and a portable transceiver could be quickly plugged in as desired. That would be a great option for the QSX when it's finally available if you'd like an all band all mode portable transceiver, or a Phaser with a Pi or small netbook could be used for digital modes, including my favorite, JS8.
He sure does! I was especially thinking about the Hamstick...
@@RadioPrepper - I'm talking myself into two 40m Phaser transceivers - one for the JS8 message server at home and another for the JS8 go box, either backpack portable or mobile in my truck.
For over a decade, I've dreamed of my Canned Ham, simple to use very portable long range EmComm transceiver. I never developed it because it would have been a huge project, but we're getting close with JS8 and the available transceiver kits such as Phaser or QSX. Ideally, it would have a resonant end fed 40m/80m wire antenna and could be used on either band depending on band conditions, with standard and custom (local group) frequencies, possibly with something similar to Automatic Link Enabling. Low antenna for NVIS regional comms or raise the antenna for DX. It wouldn't take much work to redo the Phaser to have filters that could be software switched between 40m and 80m. Ditto for the QSX, but it'll have even more band options. Make it easy to interface to a netbook PC or Raspberry Pi. There could even be an ultralight microcontroller version with a waterproof silicone keyboard and dot matrix LCD.
I've got that for 40m, to go with my QCX. I'm just finishing up the Midnight Design Solutions' Phaser transceiver, so I'll be jumping on the QCX amp next.
I will be getting the phaser too...
Are you still able to use a paddle with the qcx and 50w amp combo?
Another great video explaining the need to FOLLOW THE INSTRUCTIONS! Thank you for all the tips.
Dave K8WPE
Exactly!
Got the package in the mail. ETA is two weeks. Thanks again for all the videos. KG7CQG
Awesome thanks!! Send me the tracking number if you have one... I'll probably get it just in time for my birthday on the 26th!
Great video Gil, merci beaucoup.
From Amazon a DC to DC Step Up 30-V 10-A Regulator was added in line with my Astron 20-Amp PS to boost the voltage up to 20-volts at 10-amps for the QRP-Labs 50-watt Amp. Now the Amp is putting out an honest 51-watts when driven by the 1.7-watt Norcal 40a. What a pleasure to use. w6nfu
Great. I got a converter to step down 28V from Clanman batteries to 20V...
Good to see you screw up like the rest of us. I've tried kit building but it never works out. Somewhere during the build the smoke gets out and that's the end. Oh Well, the fun is in the trying. Enjoyed the video, more are expected, please.
Keep at it, simple ones...
I strongly recommend putting in a 470 R resistor in the the control line to the keying. This is particularly important in early revision Qcx Minis with the substandard 5V regulator. If you hot plug the control line then you risk blowing up the driver Qcx sometimes even if it is not keyed. Essentially you put the 5V regulator in pass through mode and the 14 V toasts most of the sensitive parts of the Mini, in particular the 328 Atmel. This extra resistor limits current and prevents Bad Things Happening.
Possibly later revisions of the mini are proofed against this. Early versions are easily killed via a hot plugging event. TEF
Will do thanks!
@@RadioPrepper Don't think about it.. just do it.. put it in the cable and label the cable as NO SUBSTITUTES . A sad story follows - check the version that starts in French.
When you buy the enclosure does the heatsink come along with it OR is that a separate purchase from qrplabs
I think it was in the kit itself... In any case in one of the two, not separate.
Did you ever get your slop bucket 2 going ? I have one of those kits from Steve but I still have not put it together yet. I built one of his mtr3b original kits it's one of my favorite radio's.
A friend of mine is look8ng at it right now...
Have you thought about what type of battery pack that can be built to run the amp and qcx. One that can supply 12 and 24 volt.
Thinking about using a 24V Clansman battery with a down converter...
I just received this kit for my 40 meter qcx a couple of days ago. Have you used the amp yet? How did it do? I watch all your English videos. Thanks for putting them together I always learn something.
Not yet. I just finished it...
How much is maximum power consumption from AC-DC at 20V supply?
Unfortunately I have no way to measure. See qrp-labs.com or their group on Facebook..
Very Good Video I am finishing up my 50 watt amp and waiting for the Cabient for it, tho we are in a Convid 19 Health stage, shipping is slow or not at all on imports. Your QCX unit cabient where you get it ? 73's Dale
Cabient??
I love your videos! especially when they are assemblies, I would like to purchase this kit, I have a 4watts homebrew qrp and I would like to increase his power, I will take a look at the qrp-labs website and see if they ship to Brazil, it would be great to assemble a kit as well done like that. 73 from your hamfriend from Brasil PY2NQC !
I am sure they do...
We do ;-) But include your tax number with the shipping address... because Brazilian shipments only work if the recipient tax number is there.
The -6 cores will work on 80 meters, but you will need more wire. While the recommended frequency range of the -6 cores doesn't go as low as 3.5 mhz, in certain applications this really doesn't matter. For band pass filters, the -6 cores might even give better results on 80 than the -2 cores, ask PA3AKE why.
The 6 is yellow right?
@@RadioPrepper Usually. Not all toroid core makers follow the color code, but the dash 6 cores I have are yellow.
Hi Gil, again a nice video, well done! I have a QCX-40m still without a enclosure. Which model Hammond box did you use? The board seems to fit nicely. 72, PA0CMU
I think it's a 1594bb.. Not certain... Or 1590? I can't remember...
@@RadioPrepper I found another video on your channel about the QCX. It's the 1590BB you used. Tnx! ..
Is that thermal paste safe to be on your finger? It was recommended to avoid skin contact of some types of paste. Or am I out of date?
I have no idea!
@@RadioPrepper there are some that contain products you could react to, if you haven't had any reactions you are probably ok. It is recommended to use gloves if you have to apply it with a finger. Search for "thermal paste carcinogen" for info.
I sure will use gloves next time, thanks!
Merci pour cette video en francais. Y a t il possibilité de se servir d'un Baofeng uv5r comme base avec une antenne extérieur type filaire, scoubidou,..etc ? Merci
Oui, du moment qu'elle est coupée à la bonne taille.
@@RadioPrepper . Merci pour cette réponse rapide ! Et question puissance d'émission, que peut on espérer d'une antenne filaire ?
I did not see you apply heat sink compound between the heat sinks and the case.
Darn I forgot!
FYI I haven't added heatsink compound on any of mine. In fact the improvement it makes is minor. The IRF510 is not a particularly high power device. It is cheap and it is common, and it makes a great 50W HF amp. That's why I used it.
The thermal resistance is made up of
1) semiconductor junction to TO220 tab
2) TO220 to silicone insulator tab
3) silicone insulator tab
4) silicone insulator tab to box
5) box metal
6) box external to heatsink.
By FAR the dominant term is the semiconductor junction to TO220 tab thermal resistance. This is inside the IRF510 device and you can't do anything about it. Heatsink compound between box lid and heatsink has negligible benefit as the contact area is large. Heatsink compound between IRF510 tab and the silicone pad makes very little improvement because the main thermal resistance (at least by an order of magnitude) is the semiconductor junction to the IRF510 tab.
Heatsink compound does no harm but neither, at these power levels and with these devices, does it make particularly much difference.
73 Hans G0UPL
qrp-labs.com
Can true beginner build this? if it's impossible, I wanna know how to step up stairs.
Maybe as a second kit. Better build a simpler one first..
@@RadioPrepper thx 4 ur replying. the simpler one must be a transceiver or amp?
Depends on which one... Maybe start with a Pixie or a Rock-Mite (The real one, not a Chinese knock-offs), then maybe an amp. Honestly though, 5W CW or 20W SSB is enough, no need for an amp...
@@RadioPrepper thx so much. I'll think about that a little more.
That amp I built for the video, I have used only once to test it.. Never again after that...
hey Prepper when you do a dill out like that you need to make up a cardboard chute to go under and tape it in. THen you have someone with a vaccy cleaner sucking at the top to take off the swarf while you drill. This is a known industrial technique and it works.
TE FIDLER
Indeed, I am being lazy...
excuse the Gil name I meant Giles TEF
My name is Gil.
Another fun adventure. 73 vy2js
73's et en français cela donne quoi ??
Il y aura d'autres vidéos en Français, mais la majeure partie de Mon audience parlé Anglais.
@@RadioPrepper merci d'avance car je parle le français et l'anglais cela fait 2 , encore merci pour vos vidéos
73's de F4IGB
25w for voice....try telling Italy...they stomp all over me at 5w!!!!!
I'll never understand the need...
FYI Amplifier Class is a matter of how it is biased. If you increase the bias potentiometer to around 1/4 A idle current, the transistors will operate in their linear region and it would work for SSB. Efficiency and heat dissipation will be higher so watch out for high temperature rise. Though SSB isn't continuous full power anyway - the average power will depend on what level of speech processing you have but I'd keep it not more than 25W average.
This would be experimental - I have not tested it myself and do not know how good the linearity is (and hence IMD3 performance).
73 Hans G0UPL
qrp-labs.com