Low power

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CT7ARQ
 

Posts: 49
Joined: 31 Dec 2021, 00:51
Location: Esposende - Portugal

Low power

Post by CT7ARQ »

I have a second unit bought some time ago.
Yesterday I fired up and can only get 0.20, 0.25w powered by 13.8v.
I remember wen I assembled it gived me full power all bands around 5w
Could the transistors been blown?
"There are three sorts of people: those who are alive, those who are dead, and those who are at sea"
dl6sez
 

Posts: 399
Joined: 30 Dec 2021, 22:54

Re: Low power

Post by dl6sez »

Hello OM,

if it first was 5W and now it is 0,25W or so, there should be a damage at one or more PA FETs.
Have you measured current consumption at TX?
Maybe one FET is getting very hot now.
It could also be a bad contact of the connectors between the two PCBs now...

73 de Chris
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
CT7ARQ
 

Posts: 49
Joined: 31 Dec 2021, 00:51
Location: Esposende - Portugal

Re: Low power

Post by CT7ARQ »

I noticed one is getting hot.
Will get some replacements to put.

Thank you for the help.
"There are three sorts of people: those who are alive, those who are dead, and those who are at sea"
CT7ARQ
 

Posts: 49
Joined: 31 Dec 2021, 00:51
Location: Esposende - Portugal

Re: Low power

Post by CT7ARQ »

Problem solved on the second switch of transistors.
Checked an assortment os bs170 I have and chose 3 off them. Soldered and no power output , than Afther a coffee I realized that I had used a non protected iron, so I have damadge the transistors. Using a good iron station replaced again and now is all OK.

Bs170 are sensitive to ESD damage so be careful everyone.
"There are three sorts of people: those who are alive, those who are dead, and those who are at sea"
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