RadioBanter - View Single Post

Dave Heil[_2_] · March 16th 08, 10:53 PM posted to rec.radio.amateur.moderated

wrote:
On Mar 16, 3:50� am, Dave Heil wrote:
wrote:
On Mar 9, 4:10� pm, Dave Heil wrote:
wrote:
On Mar 5, 3:20� pm, Dave Heil wrote:
wrote:
On Mar 3, 2:40�pm, Michael Coslo wrote:

Except for the reuse of possibly-contaminated 55-gal drums it all
sounds good.

Yeah, I've thought about it a great deal. � I once bought a loaf of
French bread on the street which
came wrapped in a letter I'd discarded in the trash. � It didn't bothe
r
me too much since I'd already gotten used to picking the baked
weevils out of the bread.

You owe me a new keyboard for that story.

Heh. What's funny is that after you've lived in one of those places for
a while, these things tend to seem perfectly rational. When the embassy
water pump broke, we lived for six weeks with a string of locals hiking
the five flights to our flat with a bucket full of water in each hand.
They'd dump the buck in a plastic garbage can, turn around and trot down
the stairs for another couple of buckets. We lived like that for six
weeks--taking bucket baths, doing hand wash and so forth. Keep in mind
that all water used for drinking/cooking had to be boiled and filtered
before use, whether the pumps were in operation or not.

We had a pipe burst inside a wall of our laundry room once. There was
no pipe available in town. Worker dug into the concrete wall, found the
break and used rubber tubing and hose clamps to join the broken pieces.
With every surge of the water pump, the tubing expanded and contracted,
looking like it had a pulse. WAWA--West Africa Wins Again.

The dial drum of the Southgate Type 7.... The
good copy was printed
on translucent Mylar and put on the drum.

That's a pretty inventive way to handle a homebrew dial.

TNX. Not a single new part was used. It's done a good job these past
dozen years.

That's the ultimate in junk box building and a good track record for the
finished project.

It sounds remarkably like the way Hammarlund handled the
dial/illumination in the HQ-215.

That's what inspired the design, except there's no dial cord in the
Type 7. IIRC, the HQ-215 lamps aren't *inside* the dial drum, are
they?

Yes, it is. There's only one inside the drum and another for the
S-meter. To the left of the dial window is a calibration adjustment.
To the right is an identical knob which dims the dial lamps if desired.
I desire it a lot since dimming them a bit keeps from having to put in
new lamps very often.

I received the data from Engineering.

Good. Ms. Yardley sends greetings.

Heh.

Unlike receiving tubes with their shiny
flashed getters, high power tubes often
use the anode or a coating as
the getter, and need to operate at high temperature to work.
I've read the eham thread and have even participated.

Excellent!

I don't know if it is or not. There's been some anger exhibited over
some issues. Quite a bit of erroneous information has been passed.

I'm forced to admit that I've got many of the original
transmitting and
receiving guides. � When I sold industrial electronics for
Hughes-Peters,
I rescued an old Eimac three-ring binder from the trash.
� It contains
the specs for most early and late Eimac bottles along with
applications
notes and design info for amateur amplifiers. �

Priceless stuff!

I've never even seen another of them.

Quite a number of those
notes and articles were done by Bill Orr W6SAI (SK).
� I consider Bill's
articles to be excellent.

I agree. Those articles and notes often go far beyond mere
specifications and general data, too. They often explain *why*
something is done, not just what to do.

Exactly. I'd never realized until I got the binder that Eimac had even
published amateur linear amplifier "how to" articles. A linear amp
isn't a difficult thing to design yourself if you understand why a final
tank Q within a paricular range is desired and you can use tables
published by Orr for translating the plate load impedence of a
particular bottle (run at a particular plate voltage) to find the values
of C1, C2 and L needed for the tank circuit.

A lot of the info is rather subtle. For example, if one is used to
receiving and low-power transmitting tubes with their silvery flashed
getters, where overheating causes the getter to lose its silvery
appearance, it is counter-intuitive that the gettering action of high
power transmitting tubes can actually depend the plate reaching high
temperatures.

It makes sense. There is a great difference between a receiving-type
tube run at relatively low voltages and a high power transmitting tube
run at high voltages. Their construction is quite different.

Or that, in the case of high-gain glass tetrodes like
the 4-125A, running lightly loaded can cause the glass of the tube to
soften from electron bombardment.

That sort of thing was also evident in TV horizontal output tubes. As I
pointed out in the e-ham forum, Nonex glass was used in some later sweep
tubes to help in preventing suck-in.

I think that a lot of things were tossed in the 1970s-1990s because
folks thought they'd never be needed again. Can't tell you how many
tubes and tube-related parts I acquired in those years for little or
nothing, because the folks getting rid of it thought nobody would ever
need or want it in the future.

I have enough boat anchor gear that I've taken about anything offered
over the years. Having the parts to keep something running isn't the
problem. Storage is.

This sort of thing even happens in the aerospace industry. A lot of
documentation was simply dumped as programs ended. Rocket engine
designers are going to museums to see how it was done in the past, and
have the problem of seeing what was done but not why.

I've read articles stating that NASA is having real problem as those
with knowledge of the design of such engines are retiring or have
already retired.

I can't tell you how many leftovers I have from buying material for a
project. � When I lived in Cincy, I used to hit the scrap bins of a
plastics distributor so I have quite a bit of scrap teflon, nylon and
lucite rod, sheet and tube. � Finding it when I want it is the hard
part.

Same here.

How's this for scrounging:

When this house got new siding back a few years, the antenna mast had
to come down so the siding could be put on. But when the mast was to
be reinstalled, I needed some spacers to make everything line up
correctly.

Machining metal to do the job would have been a big deal. Wood was
easy but would be a maintenance job, exposed to the weather. PVC was
too soft and not available in the right sizes anyway.

Then I remembered that relatives had redone their kitchen some years
earlier, and had gotten white Corian countertops installed. The
installers had left some Corian scraps behind. The relatives
had kept them, figuring there had to be some use for such wonderful
material.

That's one I'd not considered. What I might have considered is that
newer composite decking material which is designed to last for decades.
It can be cut easily and comes in a variety of color. I'd have likely
gone with something like that since nobody hereabouts has put in any
Corian counters lately.

Sure enough, the scraps were still available for the asking. I got
some and made the exact spacer blocks needed. Tough, weatherproof,
easy to machine, and even the right color.

Sometimes you just get lucky.

Don't want fancy. Want functional.

Keeping the XYL happy, serves a function.

Agreed.

� Keeping visiting hams from
laughing, serves a function.

They don't laugh when they see the contest scores.

That largely depends on who the visitor is.

I'm not above that. � My last crank up tower from
Tashjian/Tri-Ex had a
crate built from 22-foot-long California 2x4's and
some long, narrow
strips of plywood. � I kept it all. � I'd never even seen 22' piec
es of
2x4 stock prior to getting these. � They're reddish in color
and are of
some sort of pine not often found here in the East.

The only places I've seen such long pieces of 2x4 were in old balloon-
framed houses. One reason balloon-framing ended was the availability
and cost of such wood.

I'm not familiar with the term "balloon framing". I'm looking it up. I
don't think there's anything available from my local lumberyard in
lengths exceeding 16'.

Well, these 3,000 to 5000 square foot mega-homes
have been cropping up
everywhere in the past decade.

We call them "McMansions" in these parts. But that really applies more
to the 4,000-8.000+ sf houses we see.

There are some of 'em in Wheeling, but not many. I think those homes
were the product of a booming economy and easy credit. Those days are
over for at least the time being.

It is not unusual around here to see a perfectly good house from the
1950s to 1970s bought and torn down by a developer so a McMansion can
be built. The value is in the land - often the price of the new place
is twice that of the old. The current housing bust has mostly put an
end to that, but not completely. More than a few locals are up in arms
because it means less "affordable" housing units.

I can't really understand the "up in arms" part because we really having
a surplus of existing housing in the country. The "tear it down and
build a new one" stuff is going on in the Cincinnati area too.

The amateur radio connection to all of this is that often the house
which was torn down had mature trees good for antennas and no CC&Rs.
"Development" often removes at least some of the trees, or they don't
survive the construction process, and the new place is usually CC&R'd
to the max.

That IS a problem for radio amateurs. I think a bigger problem is that
most of our newer housing is built in subdivisions. Those subdivisions
are not radio friendly at all. I'm seeing more and more magazine
articles on stealth antennas. I won't consider living in one of those
areas.

We're sitting on an acre. If we re-locate, I'd be happier with 2 or 3
acres. I wouldn't object if half of that area happened to be in trees
or woods though.

� They're much cheaper to heat and cool
than some of the earlier built homes.

That depends on two factors: scaling (as a house gets bigger, the
interior volume grows faster than the exterior wall/roof area) and how
houses are built.

The "how houses are built" part is what I meant to address. Things like
a geothermal heating/cooling systems are another factor. W8RHM's new
place has one and it is a large house. His heating and cooling bills
are quite reasonable.

When this house got the work done a couple summers ago, and some walls
were opened, it turned out that there was no insulation. Just a thin
layer of wallboard, 2x4s, 1x10 sheathing (not plywood yet the house is
from 1950) tar paper and mineral siding. Of course insulation and
Tyvek were installed, and then the new siding.

That had to make a difference.

Same here. All about multiple uses.
...and the conservation of space.

More on that below.

The console is the key to strength.

That's why I mentioned the console. �
Everything heavy sits on it. � The
four supports for it distribute the weight so that nothing can break
through the door. � There's one large HF rig, one HF/VHF/UHF rig,
four
rotor control boxes, an HF amp, three remote coaxial switches,
three
watt meters, two speakers, an antenna tune, a RTTY/digital
modem, spare
receiver and a monitor scope on the console. � Assorted
accessory boxes
sit under the console and there's an LCD computer monitor
and a keyboard
on the desk too.

Beautiful, just beautiful..

If not beautiful, at least it isn't ugly. The console and the former
W8YX desk got hauled to each of my Foreign Service postings. The
console is approaching thirty years in age. It gets a new coat of paint
about once per decade.

One difference is that your console/desk is purpose-built for the
shack. Custom use, IOW. The op desk I use was designed to be multi-
purpose, and has been on several Field Days, as have the Southgate
rigs.

N8NN and I have been using those plastic-topped banquet tables with the
folding legs inside a screen room for FD use. That's because 1) they're
easy to set up and take down and 2) Bert has some.

When a thing is built to do just one thing, it can often be made
simple and yet high-performance for that one thing. When it has to do
multiple things, there are always more compromises.

It is really difficult to buy something which is really ideal for an
amateur radio operating position. Computer hutches/desks tend to be a
little on the small side and aren't generally as stoutly built as
necessary. For some of us, what worked really well at one point might
not be as handy years later, when the amount of gear expands to fill all
available space. I used to get by with the old W8YX desk with a 3x5'
top. The position I now use is 3x7'. If I relocate, I'll consider a
homebrew U-shaped operating position. The room I'm in at present does
not lend itself to that.

Dave K8MN