Heatsink for F2J?

[drjbf1]

I scrounged this from a 5 x 75w class A/B amp. It's 107mm high and 380mm long. Do you think it will dissipate enough heat for one channel of an F2J, which I think is 24v x 2.5A = 60w?

Thanks

 

[Zen Mod]

questionable .......

in case like that , I'm always making a test

variac , big xformer and stack of 50W dale goldies

or xformer and two mosfet CCS-es , each one set to half of desired dissipation

 

[6L6]

If you are wiling to add a fan if it's not enough, then proceed.

But best would be testing like ZM suggests.

 

[drjbf1]

Thanks for the comments. I am not a fan of fans, so will run some tests, or buy some heatsinks.

cheers

 

[drjbf1]

I thought I would report back as I have never tested heat sinks before, and it might be of interest to others.

I had bits to do a quick test as per the photo. 21v with 2 x 15R to ground, about 1.4A at 30 watts each, 60w in total, the F2J dissipation. Not sure whether the meter temp probe or the blimey test are the more accurate. After 1.5 hrs of cooking the resistors are at a constant 36C, the middle top of the sink back plate 33C and a middle fin 27C. Ambient is 18C. I can hold my hands on the sink fins indefinitely, and can keep my fingers on the resistor cases easily for 10 secs and more.

Good to go, you think?

BTW the case the sink is sitting on is reserved for the Sony Vfet Part 2. It used to house the Pass A20 from the 70's until I blew up a channel some years ago.

 

[dady]

Hi, I think that is enough for one channel. Maybe using a fan in summertime, or in Rhapsody in Blue....

 

[Zen Mod]

I thought I would report back.....

perfect

 

[drjbf1]

Thanks all.