patrick-turner;971790 Wrote:
It seems like I am the only ******* left alive on Planet Earth.
- show quoted text -
Has everyone died?
I have NOT.
Anyway, I have revised my page about the Wien Bridge oscillator with
re-done schematics including many new details.
See http://www.turneraudio.com.au/Wien-b...scillator.html
I will estimate its The Most Boring website page ever devised, unless
you'd like to make a half decent signal gene.
Of course, I have used a rotary two wafer make-before-break switch that
gives 12 F per decade evenly spaced around a dial at enough convenient F
to allow plotting most F reponses of any audio gear tested, unless a
high Q resonant filter is used, because the adjustablity of a pot of
variable C is not present.
For audio amp checking the unit is quite sufficient. Those wanting
infinitely varaible F should consider buying a dual gang reverse
direction log pot with value 15k. Lord Noze where you'd obtain one, and
one that gave you nicely spread out F around 315 degrees of rotation
with 1Hz at the max anti clockwise and 10Hz at max clockwise and 3.2Hz
at 1/2 rotation.
With a bigger box and slightly more range switch complexity you might
incorporate TWO 3 gang AM radio tuning caps with each gang 40 to 440pF
thus giving 132pF to 1,320pF which is fine for 100Hz to 1MHz, with fixed
R values. The two ranges 1Hz - 10Hz, 10Hz - 100Hz could use a pot with
fixed C and values are not difficult to implement. The variable tuning
gang as was made in 1950s is hard to beat for a WB oscillator but to get
down to 1Hz with max C = 1.320pF the R needs to be 120Meg ohms, an
impractical R value. But where you had 6 x 3gang C then C max = 3960pF,
and if your lowest range was 2Hz to 20Hz, then R need only be 20Megohms.
The minimum C = 396pF, and R need only be 200r for 2MHz. For stable
operation at such a high F you need low value R and C high enough so
stray C in devices does not make F adjustment too critical. The j-fet in
NFB network for Vo control should work up to 2MHz.
HeeLLLLOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO? anyone there? Ah, they all
musta died.
Think I'll go ride a bike, and even being attacked by magpies is just
fine.
Patrick Turner.
Still here Patrick & look in every day or two as I'm sure others do.
Today is my 81st so I will go out & do 50 km on the bike. Takes about
2h50m these daze. Twenty years ago could easily do 70 km in that time.
But August was good for 550 km anyway.
Lemme se now, your time is 2.83 Volts, and you have distance of 50 Ohms, so your average speed I = R / V = 50 / 2.83 = 17.67 Amps. It must be hilly where you are because I averaged 25.5 Amps for 91 Ohms on last Therzdi.
There's a guy of 78 in my cycling group and he does about 22kph av for about 75km, so he ain't far behind me at 26.2 usual average for the not too hilly terrain around here.
But be careful if you live to 240 years old. Maximum heart rate for many ppl is 220 - age, so if your'e 40, max HR = 180, and that's a very fine performance indeed.
But at 80, max HR = 140, also not bad, but when ya get to 240, HR max = 220 - 240 which is -20 beats a minute. I think if you cycle backwards you can avoid the problem of a negative HR.
No Magpies here, they are all in Western Canada. But we got their
relatives, Crows, Ravens, Jays & so on. The Redwing Blackbird chase in
their nesting season. Almost collided with a flying Wild Turkey a few
years ago. That would be a mess, they are kinda large.
The main threat to cycling on country roads are motorists. But the next worst thing to hit is a dopey kangaroo, can be same weight as a man, and their road sense is atrocious, so when I am decending on a mountain road at maybe 60kph, I have to keep a sharp look out for a roo which might just jump out of nowhere.
This Summer has been mostly manual labour. several trees to cut up, the
firewood pile is getting huge. There will be lots of work for the log
splitting machine in October.
Seems like you have a firewood obsession. I have an obsession with grass and hedge. Kylie and Samantha are helping out. Had row with Sam because she insisted she wear red hotpants while up the ladder with hedge clipper. Caused a couple of young blokes to crash their cars commin round the corner. I said, "Sam, safety regulations stipulate hi-viz gear, OK, so yol needta change red to grey pants and use a bright yello top...."
My electronics this Summer has been construction of a half-wave dipole
for FM. The width is obvious. All made with 1/2 inch copper pipe, so the
spacing by the formula is about 3 inches to get 300 ohms.
I have not moved up in frequency much yet, I'm still stuck below 1MHz most daze.
Works OK part way up the tower so now gotta go all the way. Without
falling off. Me, that is.
Yes, many an older man falls off a ladder or some other dang thing he shouldn't be up on.
But its a trouble many men face, they wanna do all this stuff, but they can't do it like they didded it when 25.
We seem to be getting October spring weather a month early.
Cheers to all, John