Amp Design Concept -- Preliminary
On 20 Sep 2006 02:53:13 -0700, "Telstar Electronics"
wrote in
om:
Frank Gilliland wrote:
No PCB = no cracked traces, copper seperation, no burnt boards, better
heat dissipation, more efficient conductors, etc, etc. Let's face it:
replace the power transistors more than twice on a PCB and your board
(and therfore your amp) is garbage. Not only that, but it also allows
the flexibility to use transistors of different physical sizes and
styles; i.e, the amp can be upgraded or retrofit as desired.
You're losin' it... no PCB at RF frequencies means wires and
uncontrolled inductances / resonances all over the place causing
instabilities... resulting in oscillations. Why don't you think any
commercial amps are built your way.
Great idea Frank... LOL... you're truly a great engineer!
How do you think amps and transmitters were built before the PCB was
invented? In fact, how do you think most broadcast transmitters (many
of which are still in use today) were built? By mounting a 4CX5000 on
a PCB? Why do you think the old chassis-wired Heathkits command a much
higher price than the later versions with more features but built with
PC boards? And did you know that UHF transmitters also existed long
before PC boards, were also constructed with point-to-point wiring,
and worked without the problems you claim are inevitable.... on HF?
I can cite dozens of examples of power equipment, both audio and
radio, that have histories of failure due to the use of PC boards
instead of hard wiring. I think Peavey is about the worst offender in
that department, in my own personal experience.
So you can fabricate any unfounded fear-tactic you like, the fact is
that PC boards (including the newer epoxy boards) just aren't adequate
for any high-power applications, let alone RF power applications. And
point-to-point wiring is a time-tested method that only seems to cause
problems for those who need a computer to tell them how to route the
wiring.
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