Ham Radio - Looking at the MX-P50M HF amplifier for QRP radios.

The 120 Watts spec'ed is with 28 VDC Power. As you have 12 or 13 Volts it will be about a 60 Watt PA Chip. So you are closer to full power than you are assuming.

 

Honestly, it's more like 15 to 20 watts.

When you double supply voltage, output quadruples. Half supply voltage is the opposite. You divide output by 4.

Which is telling on why people keep blowing the thing up.

--Shane
KD6VXI

 

What does honestly mean to you?

Facts are:
13.8 V = 40 W, 12 V = 30 W, 11.1 V = 28 W
https://www.dk9jc.de/blog/equipment/66-mx-p50m-50w-hf-power-amplifier-fuer-ft-817

12 V battery, maybe 12 or 12.5 V = 52 W
https://www.sm7uzy.se/art/mx_p50m.php

It also depends a bit on the band.

73, Peter - HB9PJT

 

11.1v /4 = 2.77v
11.1v+2.77v=13.8v

That's going to be a 1.5 gain multiplication.

Double collector or drain voltage would be quadruple the output. A 50 pct increase in drain or collector voltage is double power output. A 25 pct increase in collector or drain voltage would be an increase of 50 pct.

Which would be 42 watts at 13.8v vs 28 at 11.1. 28w x 1.5 = 42.

So, honestly I was pretty spot on.

What was it you thought honestly meant?

--Shane
KD6VXI

 

I attended a talk by Daniel Pink. in it he asked us what business had more locations than all the fast food places he listed. We did not know. He told us his research revealed there were more storage units than anything else. Then he asked who in the audience had a storage area. Most hands went up. Then he asked the people what they had in their storage unit. People said "stuff". Along with bikes, boxes, clothes, grandma's furniture and trinkets and so on. Then he said Americans have more "stuff" than most people anywhere in the world.

 

Hi James,

Motorola is no longer manufacturing the MRF186 but the Chinese have been making counterfeit ones that are most likely poorly made and inferior compared to authentic Motorola part.

I would recommend staying away from this one.

 

Did you buy the transistor through eBay or something? All of the replacement MRF186s I’ve seen seem to be pretty sketchy. I bought an MX-P50m recently and I’m pretty sure I blew the final, where did you pick up your replacement?