[Elecraft] QRO

[Eric Swartz - WA6HHQ, Elecraft]

Actually the APT ARF463 is a better device. It has been an excellent, 
and rugged, device for use in the KPA800 and KPA1500 amps. It has been 
very hard to kill in our destructive testing.  The only time I've blown 
one up was when I forgot to screw it down to the heat sink! (It made a 
great firecracker in that mode of operation.. :-)

These are 500V breakdown parts, which we run at 60V. Tons of headroom 
for short term high SWR events etc.

We use 16 of these transistors in the KPA1600 (four each in each of the 
four power module cards). This has the additional advantage that it 
spreads the heat dissipation over a much wider area than older designs 
that used two or four of the older Motorola devices. Lots of heat in a 
very small area equals short lifetimes for semiconductor devices. The 
Motorola parts are also much more prone to destruction in normal amateur 
abuse. These parts are also MUCH easier to replace in the field.

73, Eric   WA6HHQ


MKM wrote:
> No, it should  be here & I know which one it is and I was hoping for a 
> better device.
> http://www.advancedpower.com/rfdisplay/default.aspx?marketid=13&appid=-1
>
>
> On May 22, 2006, at 3:18 PM, Bill NY9H wrote:
>
>>
>>
>> it an APT device
>> http://www.advancedpower.com/rfdisplay/default.aspx?marketid=3:4:&appid=-1 
>>
>>
>> i'll bet it's on  this page
>>
>> bill
>>
>>
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