WANTED: 1 KW ( or larger) OIL-FILLED DUMMY LOAD

[unit_399]

I purchased a 1.5 KW Competition Amp several months back and am preparing it to go on the air. Built by the BEST amp builder out there. 8 - Toshiba 2879s. I am looking or a 1KW oil-filled dummy load like a Heath CANTENNA at a reasonable price. Anyone ???

 

[nomadradio]

A radical build for sure. At least the fans are where they belong, with the turbulent flow right out of the fan blades blowing directly on the the fins. Removes a lot more heat than squeezing it into a box with "exhaust" fans.

I'll check the one spare we have. Now that I'm operating solo, having a third spare is not so important. Then again, I'm not sure the resistor inside is okay or not. Never got around to testing it. Never seems to happen until the front-line unit fails.

Film at 11.

73

 

[snippits75]

There is a guy that is close to me that has had a Heathkit Cantenna listed on Facebook market place for a long time now for $50. He is highly rated. Link below.

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[fourstringburn]

They are fairly easy to build your own. It's basically just a bunch of non inductive resistors soldered to a bottom plate and lid of a clean paint can. You can fill it with easy to find mineral oil or transformer oil which is slightly better but costs more.

 

[unit_399]

I

There is a guy that is close to me that has had a Heathkit Cantenna listed on Facebook market place for a long time now for $50. He is highly rated. Link below.

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Log into Facebook to start sharing and connecting with your friends, family, and people you know.

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I checked the link and he states pickup only, no shipping. When I tried to message him it was not allowed

 

[Hurricane145]

MFJ used to market a "Cantenna" dummy load but they went out of business recently. You may find one still in stock at HRO or DX Engineering or some other ham gear outlet. Call around and see if you can find one but don't wait too long.

I do often see them at ham radio swap meets but that is hit and miss so may take a while to find one.

If you are in or near a larger city, put an add on Craigslist that you are looking for one. Be sure to add "ham radio" and "CB radio" in the title or text for keywords as well as other keywords that might be searched for to draw attention to you request.

 

[sp5it]

2 of those parallel: https://aliexpress.com/item/1005006780673830.htm

With proper radiator and forced air cooling will work.
Mike

 

[sp5it]

https://aliexpress.com/item/1005006780673830.html

 

[Moleculo]

Only 4 left as of this posting:

ADL-1500X, DUMMY LOAD, 1.5kW, W/O OIL

Ameritrons ADL-1500X legal limit dummy load lets you run the maximum legal limit of 1500 watts for a full five minutes. ADL-1500 has a heavy duty 50 Ohm resistor. Ameritrons Legal Limit dummy load gives you SWR under 1.2 to 30 MHz and low SWR to 400 MHz. Durable, sturdy gallon can measures 7 1/2...

mfjenterprises.com

I have used one of these for years. Works fine.

 

[nomadradio]

Finally dug this thing out and got a look inside. Just never needed it since I got it. Been in a corner, neglected for years. The top cover is grimy, but mostly with dirt and oil schmoo. Scraped off some of it, but not all by a long shot.

The oil inside is thick and nasty. Gotta dispose of that before it can go anywhere.

The inside is a lot prettier. Motor cleaner got all the oil off the inside surfaces. No visible oxidation that I see. Always a good thing.

The silver plated surfaces should get scrubbed before putting any power into it. Pretty sure the black silver tarnish isn't all that conductive.

The analyzer is happy with it. Ohmmeter said 53 ohms.

I'll get it cleaned up to ship this week. Just tell me where to send it.

73

 

[Cable Guy]

Only 4 left as of this posting:

ADL-1500X, DUMMY LOAD, 1.5kW, W/O OIL

Ameritrons ADL-1500X legal limit dummy load lets you run the maximum legal limit of 1500 watts for a full five minutes. ADL-1500 has a heavy duty 50 Ohm resistor. Ameritrons Legal Limit dummy load gives you SWR under 1.2 to 30 MHz and low SWR to 400 MHz. Durable, sturdy gallon can measures 7 1/2...

mfjenterprises.com

I have used one of these for years. Works fine.

Thanks, my old 300w load recently failed and this thread prompted me to go big. Can't wait for it to come in. Instructions say use only transformer oil, but mineral oil should be fine right? This is my first wet load. Oh, as of this moment, only 2 units are left on the mfj site.

 

[nomadradio]

Mineral oil is the standard. Unless you plan to push it beyond the specs, transformer oil will cost more without adding any benefit.

73

 

[fourstringburn]

I use mineral oil and no problems. You can find it at Walgreens or CVS and it's cheap.

 

[Shadetree Mechanic]

Mineral oil seems to be adequate.

Thread 'cooling oil for dummy load' https://www.worldwidedx.com/threads/cooling-oil-for-dummy-load.89473/

 

[928bolo]

Tractor Supply sells a gallon of mineral oil for about $25. Laxative for livestock.