12-03-2017, 04:34 PM
Hi,
I was lucky to get one of the ex UHF TV PAs here in ZL from a very kind VK3.
On the old VKlogger forums, there was a discussion about these and the VK3BEZ club had been selling these?
I have changed my Pots and set up the initial bias conditions etc without Drain power.
Started on the Wilkinson combiner and just wanted to ask a question relating to the power rating of the 100 ohm isolation resistor.
The one in the pictures looks like about 30 watt or so.
Now all things being equal etc, shouldn't see too much power dissipated in this resistor. Just wanted to gauge what people have found who have fired this up with success. Nay heat showing up and should I use say 100 ohm 100 watt? I can series up two 50 ohm ones that have leads out each side and the heat sink tab isolated.
Have put mine on a bigger and straighter heat sink.
Refer to about the 3rd pic etc in the pdf.
http://www.vk3bez.org/Files/Surplus%20NE...odules.pdf
Cheers and thanks for any feedback.
Simon
ZL1SWW
I was lucky to get one of the ex UHF TV PAs here in ZL from a very kind VK3.
On the old VKlogger forums, there was a discussion about these and the VK3BEZ club had been selling these?
I have changed my Pots and set up the initial bias conditions etc without Drain power.
Started on the Wilkinson combiner and just wanted to ask a question relating to the power rating of the 100 ohm isolation resistor.
The one in the pictures looks like about 30 watt or so.
Now all things being equal etc, shouldn't see too much power dissipated in this resistor. Just wanted to gauge what people have found who have fired this up with success. Nay heat showing up and should I use say 100 ohm 100 watt? I can series up two 50 ohm ones that have leads out each side and the heat sink tab isolated.
Have put mine on a bigger and straighter heat sink.
Refer to about the 3rd pic etc in the pdf.
http://www.vk3bez.org/Files/Surplus%20NE...odules.pdf
Cheers and thanks for any feedback.
Simon
ZL1SWW