Re: UBITX. FT8 heat sink requirements #ubitx #ft8

Ashhar Farhan

The ft8 has an overall cycle of 50%.i use it with the standard issue heatsink.
- f

On Sun, 3 Jun 2018, 16:07 Ghericoan, <boakawizkid@...> wrote:
I am not using the irf510 in my ubitx, but rather the irf630. My heatsink is an old pentium 4 sink cut in half with both fets bolted to it through mica insulators and thermal grease.

On FT8 the heatsink does a wonderful job and only gets luke warm, even with back to back QSOs. However, on modes like WSPR, I had to attach a small fan or the sink would become too hot to touch.

But I am also pretty hard on my ubitx with running the PA on 36 volts and 1-1.4 amps. (I consider one amp of current to be running the PA wide open since I use a bias current of 160ma)

On Sun, Jun 3, 2018, 5:44 AM Praba Karan <vu3dxr@...> wrote:
What are heat sink requirements of ubitx for ft8 and other digital modes?. Just binding irf510 on back panel of casing(like in sunils case) is enough to withstand heavy duty cycle demanded by ft8?

N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist

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