I am ignorant about the particular parts you are discussing. However,
caution should be used when dealing with ceramics such as this. They may be
Beryllium oxide which has excellent thermal conductivity and electrical
insulation properties, however, it is a carcinogen. A web search will reveal
lots of information on the material.
 
Regards,
Stu
W3STU.

-----Original Message-----
From: [email protected]
[mailto:[EMAIL PROTECTED] On Behalf Of DCFluX
Sent: Friday, March 21, 2008 11:48
To: [email protected]
Subject: Re: [Repeater-Builder] Anyone have a Motorola house part number
secret decoder ring?



I had to grind the flange and ceramic of the 4062 with my dremmel to
make it fit the PCB in the FT-857D. Took me 3 PPL-6060s from my scrap
pile of Johnsons before I found another one with a working final
transistor. The first transistor I salvaged didn't have the ceramic
ground down enough so when I was tightening it down with a loud pop
the ceramic seperated from the copper flange. Pissed me off because it
was still a good transistor.

Had to rebuild the triplexer feeding it. I don't know what it is but I
have seen a rash of PCB spontanious combustion in Yaesu UHF radios.
This one was burning a hole under one of the chip inductors. I don't
know, maybe FR4 doesnt like UHF?

I also had to grab a tuning cap from the Johnson to fine match the
transistor on UHF.

Got it doing 15W on UHF and 40W on VHF. It works, just not as good as
the original, About a dB and a half down, but it's cheap so who cares?
I got 46W on VHF but started to have thermal fold back problems.


 

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