UHF PA failure


Ludovic Ludo
 

Are you sure its the PA transistors that have failed?
Most often is the Driver board that fails. It runs too hot
If it is the driver, then no HF and no VHF too.
But it is not the question...

73's de Ludovic - F5PBG
http://radioamateur.forumsactifs.com/f36-ic-7000


g4abx
 

Why don't people read the subject before they post?

Err sorry, I've given you info for the HF PA :-(

So now you have a route to keep your complete rig functioning :-)

73
Bruce G4ABX


g4abx
 

Sorry, I don't know your name (Why don't people give their name when they post?)

Are you sure its the PA transistors that have failed?
Most often is the Driver board that fails. It runs too hot
The driver board is a real pain to get out and repair. You need 2 pairs of hands -- at lest!
There are some excellent videos on line that will help you -- just google 'Repair IC-7000 Driver board'

Again, make sure you have the necessary kit to undertake the repair -- and make sure you have some thermal paste to re-do the job the manufacturer should have done right in the first place!

73
Bruce G4ABX


Helmut Wabnig
 

On Fri, 18 Sep 2020 12:35:00 -0700, you wrote:

Does anyone know of a video on how to change the VHF/UHF Mosfet power amp ? Would like to review it before attempting.
Are you good in soldering?
Do you have the tools?
Without the tools it won't work.

There is nothing special. Remove the shield covers on top of the
transistor,
Remove the solder from the connections, but only where necessary.
The transistor comes off easily.

Need a strong solder tip, desoldering pump and desoldering braid,
and soldering flux.

It's SOLDER, not SODDER :-)


Actually an easy task. No special problems.
Re-solder with as little solder as possible.
HF does not like thick solder bumps.
Afte the solder work (not sodder) adjust the idle currents
as described in the service manual.

OE8UWW


va3qb <va3qb.ve3vwd@...>
 

Does anyone know of a video on how to change the VHF/UHF Mosfet power amp ? Would like to review it before attempting.