| Author |
Message |
    
Hell458
| | Posted on Thursday, April 18, 2002 - 12:49 am: | 
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anyone knows where i can purchase transformer oil for a dummy load?i try oil companies,electrical supplies,i been told to use mineral oil.hdt commercial grade fluid(i'm not sure if radio tech said it was hydralic or transmission fluid.fluid is clear.that what he uses.he also said to solder 26- 330 ohm resistor together in paint can with this fluid it can handle 1kw to 1.5kw . does this sounds right to you?any suggestions?i also have an b&w 1.5kw dummyload/meter.it has a leak,i need to fill up.it's sealed with lead.i dont want to burn oil or an explosion when i refill and seal it.any tip on resealing it?thank you for any help. |
Scrapiron63
| | Posted on Thursday, April 18, 2002 - 10:15 am: |
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When I bought mine many years ago, the instructions said Linseed oil could be used if transformer oil was not available, it drops the power handling capability about 20% I believe, but has worked fine for me. I don't have any reason to key big wattage into a dummy load for an extended period anyway. If the can starts warming up, let'er cool a little. |
Tech181
| | Posted on Thursday, April 18, 2002 - 1:00 pm: |
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Hell458,
If you use linseed oil DO NOT leave any rags that you used to clean up the oil laying around in the trash. They have a tendency of igniting on their own.
Steve
Tech181
Tech181@copperelectronics.com |
Colt
| | Posted on Thursday, April 18, 2002 - 11:32 pm: |
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Hey! I need a stinking dummy load! I used to have a Cantenna, but I sold it years ago. And I've heard somewhere about making your own as mentioned by 458 here. I'm guessing that what you do is to take a 1 gal paint can, mount an so239 in the lid facing down into the can and perhaps tee off it with a 90 degree. (Funny, I remember my old Cantenna having a box on top-wonder what that was?) Anyway, I would then solder a couple of heavy copper wires from the teminals of the 239 inside the can(missing the bottom)and connect the resistors mentioned above between them, then fill it with Linseed(not planning to run any kilowatts).
Would this be 10-8?  |
307
| | Posted on Friday, April 19, 2002 - 2:28 pm: |
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All you need to do is add standard AUTO TRANSMISSION FLUID..Thats all it is...
307 |
Wa025
| | Posted on Sunday, April 28, 2002 - 4:25 pm: |
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You can also use baby oil. It works fine. |
Chris142
| | Posted on Sunday, July 28, 2002 - 11:52 pm: |
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My dad has his cantenna he built from a heathkit back in the 60's.He said he used transformer oil,the instructions said you could use automotive engine oil but the heat dissapation would not be as good.Says any good electricle shop should have transformer oil. |
Jose22
| | Posted on Monday, July 29, 2002 - 8:42 pm: |
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Mineral oil is recomended by gold line in their 1000 watt gal. can. |
2600
| | Posted on Tuesday, July 30, 2002 - 11:55 pm: |
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Been using 10W30 for years. It's a little more flame-resistant than hydraulic fluids. Transformer oil is optimized for electical insulating properties as well as heat-carrying capacity. The voltages inside a 50-ohm dummy load don't really call for that characteristic. Unless you are planning to run the thing continuously it will be hard to tell the difference between motor oil and all the other choices above. We put a leftover electric fuel pump and transmission oil cooler on a Heath Cantenna. The pump motor struggles with the thick oil until it heats up. The pitch of the motor whine makes a sort of demented thermometer when you key for a while, getting higher as the motor oil thins with rising temperature.
73 |
Bigbob
| | Posted on Saturday, August 03, 2002 - 3:04 pm: |
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I thought transf. oil had PCBs in it which allow it to transfer heat better. |
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