Good Afternoon Roger!
With the Solid State Amps, which I'm Thinking of getting one, I too believe
that the parts May begin to be "More Available" as they "Age".
I would Hope that Someone would "Pick up" the "Slack" and "Stock pile" the
Drive Transistors so that When people Need to Replace the Drivers, they
would be Available.
On the other hand, I think it would be a Great Idea to Get a Few "Driver
Transistors" to Have, while they are still Available and Have them "On
Hand" for When the Original Set "Die".
I Also Agree that Tubes Are very "Forgiving" when they are "Over Driven".
Tubes Can and Do last a Lot Longer, just by the way they are Made!
I currently have an Ameritron AL-80B, which I Absolutely Love! I'm
"Considering" a Solid State Amp, and May "Take the Plunge" one day Soon,
but Not to Replace the Amp that I currently have, but as an Alternative
Amp, for the Power Requirements needed to Drive the Solid State Amps, being
a bit Less than that of my Tube Amp! I may be incorrect in my assumption
that the Solid State Units being less of a Draw regarding the Power
Requirements, but I need to do some more Research on the Differences
between the Requirements of All of what's available Currently!
The Tube units have a Solid History, whereas the Solid State units haven't
been in use for the same period as the Tubes, and may Never get to that
point!
I know that the Transistor "Should" last for around 100 years, Theorists
have said, but being as the Transistor has Not been in Production for
Really That Long, compared to the Tubes, we'll just have to "Wait" and see!
At this point, I'd Trust a Tube rather than a Transistor, at least for the
time being, but I may find out that the Solid State units Might just
Surprise me!
Again , Thanks for your Input!
-73-
Bill
N6FFC
On Mon, Jun 5, 2017 at 13:48, Roger (K8RI) <k8ri@rogerhalstead.com> wrote:
> Add to that, the lack of knowledge in electronics, building, and the
> general age of "old timers", module / pallet replacement seems even more
> likely. Most of today's rigs use an output module.
>
> It's probably going to mean a lot more work (and money) for those doing
> repair work.
> The old Collins and Hallicrafters rigs were relatively easy to repair
> and align. Very few of us have the knowledge and fairly expensive
> equipment to repair today's rigs so it's back to the factory, or
> authorized repair center with shipping costs as much, or more than the
> cost of repairing the old rigs.
>
> As for device / pallet, replacement we are kinda getting back to
> requirements similar to bipolar substitution, although I think gain of
> the LDMOS will be less critical than with bipolars as long as it's
> sufficient (and fits). The Yaesu Quadra is an example of an amp that
> would be easy to upgrade and make much more rugged except for the
> device. Examples do exist with the 150 W devices being replaced with 300
> W devices successfully, but the conversions were neither simple or
> straight forward and required a much more rugged Power Supply, making it
> a major rebuild.
>
> 73, Roger (K8RI)
>
> On 6/5/2017 Monday 8:28 AM, Joe Subich, W4TV wrote:
> > On 6/5/2017 3:46 AM, Roger (K8RI) wrote:
> >
> >> The current crop of new devices is likely to be around much longer
> >> than devices made just 10 years ago.
> > Given the trend to pallet based amplifiers, I doubt the device shelf
> > lifetime will be very long. Instead, rather than replace an LDMOS
> > device on a pallet, the entire pallet (input transformer, bias,
> > output transformer, spreader, etc.) will be replaced in the event
> > of a device failure much like an entire tube is replaced in a tube
> > amplifier.
> >
> > It may not matter what device (or devices) is used on a given pallet
> > so long as the I/O and form factor are the same and the new pallet
> > equals or exceeds the PO, compression point and IMD specs of the old.
> >
> > 73,
> >
> > ... Joe, W4TV
> >
> >
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> >
>
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--
God Bless...
Bill
N6FFC
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