ZL1SWW wrote:Hi all,
I have another 1296 transverter project in progress which will reside at the top of my tower. I am getting to the stage of building up the PA section.
I bought an RA18H1213G PA module from the NZ distributor for Mitsubishi.
First thing I note was the pin spacings no longer match the batch of PCBs I made for these PAs, the bias pin is wrong along with the supply pin. RF In / Out look OK.
I can get over that problem but being aware of the heatsink flange issues, I got my stainless ruler out to chek the flatness. Wow! I was horrified to see that this one looks to have about 1.5mm gap in the middle with the overall profile banana shaped.
In the past, there has been discussion about sanding off the back so it is flat all over. No way I could do that on this one as I would sand off the mounting eyes..
I will go backto the supplier but anyone else seen this? I am wondering if the disty has been had up by some chinese rip off by chance. I've heard of similiar rip offs of PA transistors.
In the meantime, it's gone back in the static bag until I find out more.
VK3AUU wrote:Has anyone thought of bending the heatsink to fit the module. The photo I saw of the heatsinh was just a 1 cm thick piece of aluminium. It wouldn't take to much force to bend that. In adittion you could put saw cuts a few cm apart to help both the bending process as well as increasing the area available for heat radiation.
There is more than one way of skinning a cat.
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