Posts by EA4HEW

Quote from ra3s

Step-by-step:

1. I removed out the both transistors and the circulator.
2. PCB, both transistors and circulator was puted in the heatsink (simple flat heatsink).
3. All fixed with screws. The most difficult job is to mark drill holes and cut threads.
4. Transistors and circulator soldered into their places on he PCB by slightly bending their leads (they have sufficient margin). This is simple.
5. PCB modifyed as described in the manual of SP8XXN and SP5XMU.
6. Unfortunately, PA hav`t PTT. Therefore, a relay was added from the outside of the PA. This PTT relay is switched on +26 V during TX.
   
   
   

Are you using the original circulator? Unsolder and solder is a great idea to eliminate the gap between the pcb and the transistors.

Quote from ra3s

The amplifier is already screwed and installed on the permanent place.

Nothing new in the my PA inside. See f.e. the photo in message #10 in this thread .

Im interesting to see your circulator solution.

Quote from ra3s

Inside photos?

Quote from DD0KP

Mechanical alianment is done now. Will post the results of this new version hopefully by end of this week.

What type of connector the PA have??

Quote from DB8TF

Inject about 100mW on the input and measure the output power.

Now use small pieces of copper foil on the input pcb trace for max output power and then add a small piece on the output trace. That worked best for me. Abt 16W with 0,5W drive. Takes some time but works.

First i tried with a network analyzer to optimize S11 on the input but then i only got 3W max out of that little PA.

vy73

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Do you have any photo of the final result?

Bird43 with slug for 2400-2500 50w

Easy for a newbie in rf with solder skills.

Quote from DD0KP

That are the drivers from the andrews ´s PAs.. should work perfect as well..

Easy to modify for 2.4ghz?