On 11/13/2011 5:23 PM, Jim Thomson wrote:
Jim asks some very good questions. There are many "off the shelf" amps
that will run the legal limit, key down, 24 X 7.
Even contesting, on SSB you are only running a fraction of this average
power. Typically it's about 20% of that unless you run compression, or
speech processing.
OTOH any of the digital modes including RTTY can run close to 100% duty
cycle. I would think most of these would likely fry the 998.
I've considered a 998 but I do run the legal limit on 160 through, 10
band edge to band edge and on 160 and 75 this leads to some pretty high
SWR readings. Even legal limit on SSB on 160 and 75 is likely to
produce some pretty high voltages. However IF you are only going to be
running the legal limit on SSB for casual conversation, you can "get by"
with a lighter and less expensive amp as long as you don't try to use it
like "the big iron".
There are also legal limit plus amps with auto tune with enough overhead
to run digital 24 X 7. Any of the amps that can run the legal limit key
down, be they auto tune of manual are going to be heavy and probably a
bit pricey compared to the Ameritrons.
However like most things, you *generally* get what you pay for.
73
Roger (K8RI)
> Date: Thu, 10 Nov 2011 20:54:10 -0700
> From: Shon Edwards<sre.1966@gmail.com>
> Subject: [Amps] What type of amplifier is best
>
> Hello all.
>
> I know I am revealing my ignorance, as most of what is on this list goes
> above my head. However, I am looking to buy an amplifier, full legal limit
> (1500 W -- US or more wattage -- I mean one which will yield an SSB
> continuous wave carrier at 1500 W for a reasonable amount of time to carry
> on QSOs), and wonder which might be best for me in my situation. I am just
> looking for something that will endure through years of use. I must admit
> I do not know anything beyond this. Perhaps you could ask me more
> questions about specific use to help you narrow down, if necessary.
>
> A couple I have been looking at buying are the following: Ameritron
> AL-1500, AL-1200, and AL-82. I'm open to others, as well. I know many of
> you are experts at making your own. Perhaps I would even go this route, if
> it would save me enough money. I have done plenty of building of
> electronic equipment in the past -- just not amplifiers.
>
> I am using an FT-857D, fed with about 100 ft. of LMR-400, attached to an
> external remote automatic antenna tuner, MFJ-998RT, and an MFJ-2990 43 ft.
> vertical antenna (all of which can handle the 1500 W or more).
>
> Again, forgive me for my ignorance; I'm sure I will get a few comments
> like, "go to school for a few years" or some such. I'm sure this would
> help, but in lieu of this, perhaps you could help me with a few ideas :).
>
> Thank you all,
>
> 73 de K6QT, Shon
>
> ## How much $$ do you want to spend..or are willing to spend ??
> Does it have to cover 160-10m.....or is 80-10m good enough??
> Does it have to cover 17+12M ?? [ some amps have lousy input swr on the
> 17/12 m bands]
> Is it for heavy duty SSB use, or will you use it for CW/RTTY/FM ??
> Does it have to sit on the desk, or can a floor console like a older henry be
> ok, space wise?
> Does it have to have QSK [assuming CW used]..or is VOX cw /ssb good enough ?
>
> Later... Jim VE7RF
>
>
>
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