On Jul 16, 4:34�pm, KC4UAI wrote:
On Jul 16, 2:27 pm, wrote:
On Jul 15, 4:30 pm, KC4UAI wrote:

On Jul 14, 5:55 pm, wrote:
On Jul 14, 3:10 pm, KC4UAI wrote:
On Jul 11, 8:44 pm, wrote:
My point was that it was not only possible to do FD with tube
gear, but that it's possible to get decent results using it.

I don't disagree with you there. �The old stuff works, but tube g
ear
is going the way of the spark gap stuff.

No, it isn't. Spark was first abandoned by hams and then outlawed; the
whole transition from King Spark to museum or junkpile took less than
ten years.

Tube rigs are different. Of course they're a special niche interest,
like many other things in amateur radio. But there's a very active
community of hams restoring old tube gear and building new ones.

(Unless some bright cookie
figures out that there are just some things a tube can do better and
cheaper than solid state stuff.)

There are, such as RF power amplifiers for HF and low VHF. While it is
certainly possible to build the solidstate equivalent of, say, a
single-3-500Z HF amplifier, the SS version costs more and is less
efficient.

You'll not see new manufactured stuff using tubes for a variety of
reasons, but for the homebrewer, experimenter and restorer they are a
possibility. In fact, one of the reasons for the high prices of tube
gear is the increasing interest in it!

But the main point is that there's an ever-widening variety of options
out there for us hams. An amateur running a rig made of pre-WW2 parts
can be in QSO with one using the latest SDR lashup, or anything in
between. The RF doesn't care.

Personally, I'm worried that with the increased
average age for your
local ham translates into lack of interest for
those of us who are
younger (say mid 40s). I see this as a problem
for contests and not
just the hobby in general.

But is the "average age" really increasing,
compared to the "average
age" of the US population in general?

Or could it be that the younger hams are too
busy working, studying, and
raising families to go to many ham radio
gatherings and be seen?

Well, I know that I'm busy with those things at 40.

Exactly. So are many others. Life has changed from
the "Ozzie & Harriet/Leave It To Beaver" days.

�Before the FCC
removed the information from the public view, the
average age of hams was on the increase.

I think there's more to it than that.

First off, AFAIK what really happened is that FCC
has gone through periods when they collected
birthdate date, and others when they did not.

If you look up my call on QRZ.com, you'll see I was
born in 1954. But your birthdate info is not given. Unless
I missed something, that's because when I got my license
the FCC was collecting birthdates and when you got
yours, they weren't.

What that means is that you can still derive "average age"
data from the FCC database, but it will be skewed data
because it only covers hams who were first licensed in
certain times. So it's worse that useless because the
youngest hams won't be counted at all.

�ARRL membership is getting older I'm told. �I
don't think the trend has changed and I don't think that it is just a
function of the increase in your average life expectancy and the
general trends.

But how do we really know? Does ARRL keep birthdate info on all
members?

�I think your average ham is older than average Joe on
the street and the distribution of age is skewed towards the high
end for hams by quite a bit.

But without hard data we don't really know.

I do know that from 1990 to 2000 the median age of US residents in the
census rose almost 5 years, from 34 years and some months to 39 years
and some months. So the median American today is probably over 40
years old.

But there are very few hams under the age of 10 or 12, so the median
age of US hams should be quite a bit older than the median age of the
US population. So a median age of hams in their 50s or older, and a
rising number, is not out of whack with what's going on with the US
population.

So perhaps you see the effects of both in contest participation. ï¿
½I
know that I have difficulty getting the HF radios turned on for an
hour or so more than a few times a month and there is no way I
can spend a whole 24 hours doing some contest.

Sure. But contest participation doesn't have to be for the full
period.

�I have my hands full with
work, mowing the grass, fixing the cars and being a husband and
father.

Which is why hams in your age bracket, and mine, are so much less
visible.

73 de Jim, N2EY

On Wed, 16 Jul 2008 20:51:14 EDT, wrote:

There are, such as RF power amplifiers for HF and low VHF. While it is
certainly possible to build the solidstate equivalent of, say, a
single-3-500Z HF amplifier, the SS version costs more and is less
efficient.

Yet the broadcast industry is going to SS as fast as they can.
Modular in design, if one "final" module fails, the power gets reduced
but they stay on the air. If a "final" tube fails, it's February
2009 much sooner. Reduction in maintenance costs outweigh capital
investment. I don't think that you can buy a new AM broadcast
transmitter below 50 KW that isn't SS all the way, and there are
plenty of SS 50 rigs in service.
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net

Phil Kane wrote:
On Wed, 16 Jul 2008 20:51:14 EDT, wrote:

There are, such as RF power amplifiers for HF and low VHF. While it is
certainly possible to build the solidstate equivalent of, say, a
single-3-500Z HF amplifier, the SS version costs more and is less
efficient.

Yet the broadcast industry is going to SS as fast as they can.
Modular in design, if one "final" module fails, the power gets reduced
but they stay on the air. If a "final" tube fails, it's February
2009 much sooner. Reduction in maintenance costs outweigh capital
investment. I don't think that you can buy a new AM broadcast
transmitter below 50 KW that isn't SS all the way, and there are
plenty of SS 50 rigs in service.
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net


The SS transmitters don't sound as good as their tube counterparts: I
worked at a station that had a SS transmitter in the 5K class, and
whenever we switched the "old" unit on so we could maintain the new one,
I heard a noticeable improvement in sound quality. It was subtle, and I
was in the business, but it was definitely there.

The management loved the SS unit because it took less power, but I was
disappointed with the sound.

My 2¢.

73,

Bill W1AC

--
Bill Horne
(Remove QRM from my address for direct replies.)

On Jul 20, 8:20 pm, Phil Kane wrote:
On Wed, 16 Jul 2008 20:51:14 EDT, wrote:
There are, such as RF power amplifiers for HF and low VHF. While it is
certainly possible to build the solidstate equivalent of, say, a
single-3-500Z HF amplifier, the SS version costs more and is less
efficient.

Yet the broadcast industry is going to SS as fast as they can.
Modular in design, if one "final" module fails, the power gets reduced
but they stay on the air. If a "final" tube fails, it's February
2009 much sooner. Reduction in maintenance costs outweigh capital
investment. I don't think that you can buy a new AM broadcast
transmitter below 50 KW that isn't SS all the way, and there are
plenty of SS 50 rigs in service.

Of course! But that shows the difference between Amateur Radio and
other services.

Perhaps I should have specified that the comparisons I was making were
between SS and tube amps meant for Amateur Radio service, particularly
HF and VHF service.

A broadcast transmitter has to be ultra-reliable and built for
continuous service. At 8760 hours in a standard year, it doesn't take
long for a component with an expected life of 10,000 or 20,000 hours
life to require replacement. Which BC folks tend to do on a schedule,
rather than waiting for failure to force the issue.

But with a very few exceptions, an amateur transmitter spends very
little time actually transmitting. I'd guess that most active amateurs
are on the air less than 1000 hours per year (that's about 2-3/4 hours
per day, every single day), and when they are on the air, most spend
at least half their time listening. OTOH, most amateurs will change
frequency at least once in a while...

So while the BC station owner can justify the purchase of an SS
transmitter based on lower maintenance costs, the amateur is usually
more limited by first-cost.

73 de Jim, N2EY

Phil Kane wrote:
On Wed, 16 Jul 2008 20:51:14 EDT, wrote:

There are, such as RF power amplifiers for HF and low VHF. While it is
certainly possible to build the solidstate equivalent of, say, a
single-3-500Z HF amplifier, the SS version costs more and is less
efficient.

Yet the broadcast industry is going to SS as fast as they can.
Modular in design, if one "final" module fails, the power gets reduced
but they stay on the air. If a "final" tube fails, it's February
2009 much sooner. Reduction in maintenance costs outweigh capital
investment. I don't think that you can buy a new AM broadcast
transmitter below 50 KW that isn't SS all the way, and there are
plenty of SS 50 rigs in service.
--

We hams are starting to see some higher power amplifiers available but
at rather breathtaking prices. I've drooled over a couple of the Tokyo
Hi-Power offerings and I have a friend running the Yaesu Quadra. I
think the MFJ/Ameritron folks will need to get into the solid state amp
game before we see *affordable* solid state amps with outputs of 1 to
1.5 KW. Only when that happens will I make my move to a solid state amp.

Dave K8MN