You did a great job, I got the can at ace, got resistors on e- bay, and one sided circuit board on e-bay! Mine were 3 watts so it should do legal power or a little less. My three tube 811 will not do 1 kw any way. Very sad nothing made in the USA! Our politicians have sold our job’s away to China. What a shame. I am glad I am old! JohnBoyUtah KJ7TBR 🇺🇸😎📡🎙🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸
You have 16 banks of 5w resistors. That makes 80watt not 240w. You would have to have all 48 resistors in parallel to get to 240w. Plus they are all touching each other. You need a gap between all the resistors for the oil to work at dissipating extra power.
Just for future reference, mineral oil will not go rancid like cooking oil. On a separate note, most Ace Hardware's stock new empty Gallon Paint Cans for $4.99 each.
"Rancid" cooking oil has a smell, no doubt. But it still cools just the same. You may wish to change it out every 18 months, but it is certainly cheaper than mineral oil !!
Lester’s stuff is way over priced! I was disappointed that he did not give resistor values, but it is reverse engineered real easy! Yours is a good video. I was told that the relief valve is important in the lid ! Like the Heath Kit version! JohnBoyUtah KJ7TBR 🇺🇸🇺🇸🇺🇸😎🎙📡
I did not. that is what Lester claimed in his build video, and that was suppose to be "peak-envelope-power" SSB and intermittently at that. I merely reverse engineered is so people could build it. Lester never told what the resisters were, how many or what wattage. I used 48 270 ohm, 5 watt resistors in series-parallel. I needed something to test with that would hold at least 100 watts straight power, and i figured this would do the trick.
This is suppose to handle 2500 watts Peak Envelope Power.... I.E. sideband. And i'm thinking probably not continuous! I bought a lot of fifty 5 watt, 270 ohm resistors for my build. got them off EBAY. It took 48 resistors i believe.Getting an empty metal paint can was difficult too. www.ebay.com/itm/311310282887?hash=item487b89f087:g:~qQAAOSw435iPI3r&amdata=enc%3AAQAHAAAA8JkApe8m76fsf0jGhgVzX%2Bp8byezzq%2BWKXKyKftPLzVAV0Un%2FeZsn4MNhLUfU41Wxt%2Fp3VaPAaIk%2BskQKPLBkAphCDriHMgrE4Vx9aQnOM7blxXjFDGJDLlMB7Qo0ZwHxmth6a%2ByDUhHvkot75rQiwL0EcC1hg5Lzrrq9Q1wUc33%2FBGRjCduN8voxocrnwMvhSi6DNMXuYY3F3oBua4YISriU6jU%2BuMg1FXGptFxxR6fimTJBtKxJnkdnwbeZU%2B%2B46Ts1n0NDteIoau4mCmmcvKvz8xoaIaLypbpEvpBEcAvBsAy9gJeEEMH8y0Zn31pjQ%3D%3D%7Ctkp%3ABFBMjOysjf9g
You did a great job, I got the can at ace, got resistors on e- bay, and one sided circuit board on e-bay! Mine were 3 watts so it should do legal power or a little less. My three tube 811 will not do 1 kw any way. Very sad nothing made in the USA! Our politicians have sold our job’s away to China. What a shame. I am glad I am old! JohnBoyUtah KJ7TBR 🇺🇸😎📡🎙🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸
1kw would probably melt down my antenna!
My antenna is a SF360 , 1kw, from Sigma Comm in the UK! It will handle power from the three tube 811 I am sure! 73 JohnBoyUtah KJ7TBR 🇺🇸😎🎙📡
Great video. How is the heat dissipation in oil calculated? How long can you use say 1kw continuous before the resistors get too hot?
I have NO idea!!!! I don't even have a transmitter that will produce 1KW!!! If you try it out, please post the results here!
You have 16 banks of 5w resistors. That makes 80watt not 240w. You would have to have all 48 resistors in parallel to get to 240w. Plus they are all touching each other. You need a gap between all the resistors for the oil to work at dissipating extra power.
Just for future reference, mineral oil will not go rancid like cooking oil. On a separate note, most Ace Hardware's stock new empty Gallon Paint Cans for $4.99 each.
Thanx! That's good to know!
"Rancid" cooking oil has a smell, no doubt. But it still cools just the same. You may wish to change it out every 18 months, but it is certainly cheaper than mineral oil !!
@@lomgshorts3 you can either spend $20.00 on a gallon of mineral oil ONCE or $6-8 for cooking oil five or more times.
Is it vital that the pain can be metal? All RF is directly returned correct?
Yes. the can acts as a Faraday shield for the RF energy.
Lester’s stuff is way over priced! I was disappointed that he did not give resistor values, but it is reverse engineered real easy! Yours is a good video. I was told that the relief valve is important in the lid ! Like the Heath Kit version! JohnBoyUtah KJ7TBR 🇺🇸🇺🇸🇺🇸😎🎙📡
I did eventually add the power output jack like on the Heathkit cantenna. I just built it on a tie point terminal strip fastened to the SO-239 bolt.
@@rusty1187any chance you can add a link to what you used? Thanks.
Hello. You mention a relief valve, can you provide a link to where we can see the style/ model/ brand of said valve, or where to purchase one? Thanks.
How did you determine that this is a 2.5K watt unit?
I did not. that is what Lester claimed in his build video, and that was suppose to be "peak-envelope-power" SSB and intermittently at that. I merely reverse engineered is so people could build it. Lester never told what the resisters were, how many or what wattage. I used 48 270 ohm, 5 watt resistors in series-parallel. I needed something to test with that would hold at least 100 watts straight power, and i figured this would do the trick.
How many Watts????????😮
What size can did you use?
I used a one gallon paint can, and 48 270 ohm 5 watt resistors
how to make a dummy load 50 Ohm 100W support 0-3Ghz Frequency?
the resistor lead lengths would definitely be a factor!
Error + error
Can’t get those resistors any more Lester bought them all from China Skum Bag!
This is suppose to handle 2500 watts Peak Envelope Power.... I.E. sideband. And i'm thinking probably not continuous! I bought a lot of fifty 5 watt, 270 ohm resistors for my build. got them off EBAY. It took 48 resistors i believe.Getting an empty metal paint can was difficult too.
www.ebay.com/itm/311310282887?hash=item487b89f087:g:~qQAAOSw435iPI3r&amdata=enc%3AAQAHAAAA8JkApe8m76fsf0jGhgVzX%2Bp8byezzq%2BWKXKyKftPLzVAV0Un%2FeZsn4MNhLUfU41Wxt%2Fp3VaPAaIk%2BskQKPLBkAphCDriHMgrE4Vx9aQnOM7blxXjFDGJDLlMB7Qo0ZwHxmth6a%2ByDUhHvkot75rQiwL0EcC1hg5Lzrrq9Q1wUc33%2FBGRjCduN8voxocrnwMvhSi6DNMXuYY3F3oBua4YISriU6jU%2BuMg1FXGptFxxR6fimTJBtKxJnkdnwbeZU%2B%2B46Ts1n0NDteIoau4mCmmcvKvz8xoaIaLypbpEvpBEcAvBsAy9gJeEEMH8y0Zn31pjQ%3D%3D%7Ctkp%3ABFBMjOysjf9g
Yea I can't stand him either.
@@rusty1187 i thought you had to use carbon film if submerged in oil??
@@andrewverran3498 i believe that's what i ordered. NOT wire-wound!