¿ªÔÆÌåÓý

  1. BITX20
  2. Topics

RF Situation Resolved.

 

Howard (WB2VXW) called this morning and we went thru quite a bit of testing and things were not added up, until I mentioned that I had replaced the heatsink, made sure it was isolated from ground but forgot the FETs needed to be isolated from each other as well.
Thanks Howard, that was a stupid mistake on my part. I own it!
Farhan forgive me for suggesting there might have been a possibility of rushing the board out, getting ready for the release of V4.0
Chip
N5FJK
 

¿ªÔÆÌåÓý

Glad to help.

On 6/21/2018 4:03 PM, Latham, Chip wrote:

Howard (WB2VXW) called this morning and we went thru quite a bit of testing and things were not added up, until I mentioned that I had replaced the heatsink, made sure it was isolated from ground but forgot the FETs needed to be isolated from each other as well.
Thanks Howard, that was a stupid mistake on my part. I own it!
Farhan forgive me for suggesting there might have been a possibility of rushing the board out, getting ready for the release of V4.0
Chip
N5FJK


[email protected]
 

I just need some clairifaction on replacing the heat sinks on uBITX. ?I am in the process of maching out a new heat sink, which will be one piece. ?If I am correct, ?if I mount each FET with the correct mounting pads and they don't touch they should work fine or am I missing something here. ?I just don't want to manufacture a problem.?
Thanks, 73
Buddy, KJ4ZSI
M Garza
 

One big heatsink is fine, as long as both FETs are insulated from it.

I plan on doing this, once I get to putting things in a case.

Marco - KG5PRT?


On Fri, Jun 22, 2018, 12:14 PM <hotrod541@...> wrote:
I just need some clairifaction on replacing the heat sinks on uBITX.? I am in the process of maching out a new heat sink, which will be one piece.? If I am correct, ?if I mount each FET with the correct mounting pads and they don't touch they should work fine or am I missing something here.? I just don't want to manufacture a problem.?
Thanks, 73
Buddy, KJ4ZSI

 

Make sure you are using an insulating kit including the screws and the back either mica or other insulator. No continuity between the gates after mounting the irf510's
Using the insulating mounts you wont have to worry about the 12DC being shorted to ground by accident if using a metal case. Since the IRF510 are 180 degrees out of phase if they short on the heat sink you will blow?them, like I did.
Hope that helps
C?

1 - 5 of 5