开云体育

All,

I'm writing a program to calculate the numbers on power transformers.
I named it Maxwell, as I figured he was the first to come up with the
formulas himself. I uploaded the pics to the photo directory for this
group. I will eventually have this for sale as shareware in the near
future. Are there any thing you would like to see added to it? All
comments are welcome.

Thanks,

Will

Noel,

Please see this page for lots of links to both retrofits and homebrew amps using the GI-7B including one in progress by Bob,VK3ZL: <>

73, Tony W4ZT

vk4hr wrote:

First post from a new member and already asking questions.
Has anyone had any experiences "good or bad" with the Russian GI7B
tubes. Just chasing information for a club project a "single band amp"
for possibly 40 or 20.

Noel
VK4HR

Hsu,

That formula is for 60 Hz, I forgot to add that. The
difference between 50 Hz and 60 Hz transformer size is
a factor of 1.2. A 50 Hz transformers core will be 1.2
times larger than a 60 Hz for an equivelant power output.

Best,

Will


--- In ham_amplifiers@..., "craxd" <craxd1@...> wrote:

Hsu,

There's a short formula one can use to estimate the power by the

core

area providing they have the wire sized right. You use the core

area

(a) in square inches. A hint to make it easy to measure is the
outside leg of a transformer is most always 1/2 as wide as the core
width. So multiply the leg width by 2 to find the core width. Next,
multiply that by the irons stack thickness and that will give the
area. The formula works with 12 kilogauss. If they're running it
higher, the core could be smaller for the same power rating. You'll
have to convert centimeters into inches as the formula is for

square

inches. Theres 2.54 centimeters in a lineal inch. To convert into
square centimeters, multiply square inches by 6.45.

a = (leg width in inches x 2) x cores stack thickness in inches

P = ( a / 0.1725 )^2

This will get you close.

Best,

Will



--- In ham_amplifiers@..., "Hsu" <Jbenson@> wrote:

Thanks,Will
Could tell me the power rating of TL922 HV transformer?
Thanks again!
73! Hsu
----- Original Message -----

Hsu,

There's a short formula one can use to estimate the power by the core
area providing they have the wire sized right. You use the core area
(a) in square inches. A hint to make it easy to measure is the
outside leg of a transformer is most always 1/2 as wide as the core
width. So multiply the leg width by 2 to find the core width. Next,
multiply that by the irons stack thickness and that will give the
area. The formula works with 12 kilogauss. If they're running it
higher, the core could be smaller for the same power rating. You'll
have to convert centimeters into inches as the formula is for square
inches. Theres 2.54 centimeters in a lineal inch. To convert into
square centimeters, multiply square inches by 6.45.

a = (leg width in inches x 2) x cores stack thickness in inches

P = ( a / 0.1725 )^2

This will get you close.

Best,

Will

Thanks,Will
Could tell me the power rating of TL922 HV transformer?
Thanks again!
73! Hsu

Jim,

Did you ever try paper tubing for the chimneys? It's the same
kraft paper they use in transformer insulation. No hotter than
a tube gets with the blower running, it wont hurt anything.
This stuff is made in 10 foot lengths but can be bought
shorter through paper suppliers that make and sell cardboard
boxes, etc. A company named U-Line has a good selection of
large diameter tubing that would make a good chimney. A compamy
who makes the tubing is Precision Paper Tube. They make the
tubing used in inductors, etc.

Another way is to fabricate one from fish paper, or the
blue-grey stuff used again as transformer insulation. It has
a clay added to it. It runs well as a chimney and one can roll
it up as a cone shape so its wider at the bottom as in some
chimneys.

The last is to make a fiberglass chimney. One can buy the
fiberglass sheet and the resin from Sears and some
auto-body suppliers. Sears carries it in their boat
specialties catalog. You'd have to make a form for say a
cone shape out of teflon so the resin wont stick to it.
An aluminum form might work to using a release agent.

Best,

Will



--- In ham_amplifiers@..., "pentalab" <jim.thomson@...>
wrote:

Gents

I just posted some new pix.[page-3 of my pix page]..... depicts

how

we paralleled the 3 x wafers of the Model 85 switch. We
used 1" wide CU strap... x .022" thick... formed into a..."U".
Each strap was formed on some scrap square material..... forget
the precise width... believe it was aprx 3/8" wide. This
allows for maintaining the 13 KV air gap between adjacent
contacts. Using 1" wide strap... in a "U", also allows for
zip stray L through the 3 x wafer's... and also will handle
literally globs of RF current.


Wafer at back end... closest to tank coil, we call wafer #1....
this is where the various coil taps terminate. The wafer
closest to the front panel/knob, is wafer #3. The output of
this switch is on wafer #3..... which of course, feeds both the vac
load cap and the low freq end of the huge Multronics Jumbo tank
coil. This "in on wafer #1.. and out on wafer #3" allows for an
almost even RF current sharing, between the 3 x paralleled

wafers.

This same scheme has also been done on a model #88 switch. Just
make sure you use "double commons" on all 3 x wafers.. on any of
these series of switch's. The double commons allows grabbing
the central rotor hub on BOTH sides.... handles WAY more RF

that

way. Stock, they only come with one common per rotor... grabbing
the rotor on the top side only. Skip Coleman at Multi-tech
Industries supplied me with all the bits and pieces I needed
for my model 85 and 88 switch's. There is also a pix depicting
the "double commons" portion of the switch... [page 2 of pix

page]

The next pix just shows a close up of the surplus [$20.00]
Multronics 14 uh tank coil model MI-14 [it actually measures
12.2 uh] It came with just one multronics 1/2" tubing
clamp. A friendly machinist made a bunch more for us... virtual
carbon copies too ! Good thing too... since Multronics wanted
$50.00 for EACH tubing clamp ! ....ouch. Taps from the triple
wafer bandswitch to the Multronics coils, etc... was done using
1" wide flat strap x .022" thick.... zip stray inductance....
even though most of the taps were very long. Else where on the

pix

page... shows the HB 1/2" tubing coil.. smaller ID [3"] used
for 20-17-15m.... it was added to the HF end of the 12.2 uh
Multronics coil....which has a huge ID to it. Tapped for 160-

80-

60-40-30-20-17-15m.... NO 10/12m.

The last new pix, shows the 1 in 9 out 15 kw remote ant
switch... from a different angle. The strap is all 3/4" wide
x .022" thick... spaced aprx 5/16"... which gives us 50 ohms.
Although the DPDT relays are rated for just 277 Vac... they
hi - pot tested to 3 kv..... and have had as much as 17 kw

pumped

through em........ surplus $4.00 each. 12 vdc. I

previously

posted the url for both these surplus 12 vdc DPDT relays... and
also the 3 x pole contactor's [with 220 v coil].

Later........ Jim VE7RF

Gents

I just posted some new pix.[page-3 of my pix page]..... depicts how
we paralleled the 3 x wafers of the Model 85 switch. We
used 1" wide CU strap... x .022" thick... formed into a..."U".
Each strap was formed on some scrap square material..... forget
the precise width... believe it was aprx 3/8" wide. This
allows for maintaining the 13 KV air gap between adjacent
contacts. Using 1" wide strap... in a "U", also allows for
zip stray L through the 3 x wafer's... and also will handle
literally globs of RF current.


Wafer at back end... closest to tank coil, we call wafer #1....
this is where the various coil taps terminate. The wafer
closest to the front panel/knob, is wafer #3. The output of
this switch is on wafer #3..... which of course, feeds both the vac
load cap and the low freq end of the huge Multronics Jumbo tank
coil. This "in on wafer #1.. and out on wafer #3" allows for an
almost even RF current sharing, between the 3 x paralleled wafers.

This same scheme has also been done on a model #88 switch. Just
make sure you use "double commons" on all 3 x wafers.. on any of
these series of switch's. The double commons allows grabbing
the central rotor hub on BOTH sides.... handles WAY more RF that
way. Stock, they only come with one common per rotor... grabbing
the rotor on the top side only. Skip Coleman at Multi-tech
Industries supplied me with all the bits and pieces I needed
for my model 85 and 88 switch's. There is also a pix depicting
the "double commons" portion of the switch... [page 2 of pix page]


The next pix just shows a close up of the surplus [$20.00]
Multronics 14 uh tank coil model MI-14 [it actually measures
12.2 uh] It came with just one multronics 1/2" tubing
clamp. A friendly machinist made a bunch more for us... virtual
carbon copies too ! Good thing too... since Multronics wanted
$50.00 for EACH tubing clamp ! ....ouch. Taps from the triple
wafer bandswitch to the Multronics coils, etc... was done using
1" wide flat strap x .022" thick.... zip stray inductance....
even though most of the taps were very long. Else where on the pix
page... shows the HB 1/2" tubing coil.. smaller ID [3"] used
for 20-17-15m.... it was added to the HF end of the 12.2 uh
Multronics coil....which has a huge ID to it. Tapped for 160-80-
60-40-30-20-17-15m.... NO 10/12m.

The last new pix, shows the 1 in 9 out 15 kw remote ant
switch... from a different angle. The strap is all 3/4" wide
x .022" thick... spaced aprx 5/16"... which gives us 50 ohms.
Although the DPDT relays are rated for just 277 Vac... they
hi - pot tested to 3 kv..... and have had as much as 17 kw pumped
through em........ surplus $4.00 each. 12 vdc. I previously
posted the url for both these surplus 12 vdc DPDT relays... and
also the 3 x pole contactor's [with 220 v coil].

Later........ Jim VE7RF

On Oct 25, 2006, at 1:04 PM, craxd wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 24, 2006, at 9:05 PM, craxd wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

...
Correct. He didn't like the fact that an oscilloscope indicated a
worst-case potential in a SB-220 that was only about 1/3 of what he
predicted it would be. This potential is on the verge of arcing the
Tune-C, so even if the voltage tried to rise much higher, the cap
would zap and limit the voltage like a zener diode. The reason he
wanted the potential to be higher was to explain away what I said was
parasitic arcing by the SB-220's occasional 110MHz oscillation.

The peak or peak to peak voltage one reads is exact,...

Porcine shampoo. I'm a guy who used to calibrate oscilloscopes.

Wouldn't you agree they're exact to within their tolerance?

No. Exact means without error -- within tolerance means within a specified error.

If the cal equipment used is correct, and the scope is ran
in a similar enviroment temperature wise, etc, it should show
close to the same as what it was calibrated to read.

Correct -- which is not without error.

That is
provided it's withing calibration and hasn't been tampered
with. I'm not saying it's exact with no deviation, but it's
one of the most exact ways we have reading an AC voltage. 3%
or less tolerance is pretty darn good. According to the
Tektronix manuals, they should be capable of better than 3%.

A calibrated oscilloscope is one way power meters can be

calibrated

and it's much faster than using a bomb-calorimeter. However, an
oscilloscope is as useless as tits on a boar hog for measuring
cleanliness of a SSB signal.

Well it's according to what you term clean. Harmonics no, unless

you

build or use a front end for this like the poor mans spectrum
analyzer, or one of the commercial add-on units. Over modulation,
hum, noise, regeneration, and parasitics can all be seen using a
standard scope.

But not SSB IMD.

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

Best,

Will





Yahoo! Groups Links

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

MFJ does sell a stand alone dip meter that's decent as I have
one of them. MFJ doesn't manufacture this meter either, they
have them branded by an asian manufacturer. It's the same dip
meter as the Leader solid state and a few others. I'd trust
it more than the analyzers that MFJ made by a long shot.

I compared the one they're selling to the Heathkit one I have,
and they work similar to the same.

Best,

Will


--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 24, 2006, at 2:49 PM, pentalab wrote:

--- In ham_amplifiers@..., Bill Turner <dezrat@>
wrote:

ORIGINAL MESSAGE:

On Mon, 23 Oct 2006 00:20:30 -0000, "craxd" <craxd1@>
wrote:

If a dip meter shows a
resonance, there is a resonance at its tuned frequency. Forget
reading the freq off the dial, simply couple it to a known

accurate

freq counter, it will show the truth if you want precision.

------------ REPLY FOLLOWS ------------

One needs to be careful with this. The typical single-tube or
single-transistor dip meter can be pulled considerably off the

true

resonant frequency if coupling is very tight to a high-Q circuit.

Just

physically move the dip meter away far enough so the dip is

barely

perceptible and the accuracy will improve greatly.

If you have used a dip meter much, you have no doubt had the
experience of tuning slowly across the dip, and as you continue

tuning

have the dip suddenly disappear as the pulling effect disappears.
Loose coupling will prevent this from happening.

### Highly agreed. Loose coupling is as good as it gets.... for
acuracy anyway. Mike Stahl, K6MYC warned me about this 25 yrs
ago.... he didn't trust em.. when tweaking yagi's.... I wouldn't
either.

According to a friend who loaned him a dipmeter, he did not

realize

that a plug-in coil had to be inserted to make it work.

### For a real laff.... I bought the "mating" grid dip osc
coils for my MFJ-259 analyzer. Two coils cover the entire
spectrum. I can't grid dip ANYTHING with em... even simple
stuff.. like a coil in parallel with a cap... on the test bench.
Then I find out nobody else can grid dip anything either! Then

Rauch

sez they don't really work. They still don't. It was
suggested not to buy the optional coil(s).

With MFJ, $elling is the object, working is not

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 24, 2006, at 9:05 PM, craxd wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 22, 2006, at 5:20 PM, craxd wrote:

Jim,

It's a wonder Tom didn't add a "by the way" saying, scopes and

dip

meters are very inaccurate and should never be used. : ) At

least

he

answered you by e-mail, he never would me.

He did not tell me this via e-mail. He said dipmeters were

worthless

during a discussion of various means of grounding grids after a
dipmeter measurement showed a result that contradicted his dicta
about grounding grids.

No, I meant I wouldn't doubt that he would have said
this to Jim.

If a scope is calibrated properly, or a dip meter the same, they
can't lie. They can only show you the truth.

That IS the problem here.

If a dip meter shows a
resonance, there is a resonance at its tuned frequency. Forget
reading the freq off the dial, simply couple it to a known

accurate

freq counter, it will show the truth if you want precision. A
calibrated scope can only show a waveform that it produces from

what

it sees at the input jack.

Correct. He didn't like the fact that an oscilloscope indicated

a

worst-case potential in a SB-220 that was only about 1/3 of what

he

predicted it would be. This potential is on the verge of arcing

the

Tune-C, so even if the voltage tried to rise much higher, the cap
would zap and limit the voltage like a zener diode. The reason he
wanted the potential to be higher was to explain away what I said

was

parasitic arcing by the SB-220's occasional 110MHz oscillation.

The peak or peak to peak voltage one reads is exact,...

Porcine shampoo. I'm a guy who used to calibrate oscilloscopes.

Wouldn't you agree they're exact to within their tolerance?
If the cal equipment used is correct, and the scope is ran
in a similar enviroment temperature wise, etc, it should show
close to the same as what it was calibrated to read. That is
provided it's withing calibration and hasn't been tampered
with. I'm not saying it's exact with no deviation, but it's
one of the most exact ways we have reading an AC voltage. 3%
or less tolerance is pretty darn good. According to the
Tektronix manuals, they should be capable of better than 3%.

A calibrated oscilloscope is one way power meters can be

calibrated

and it's much faster than using a bomb-calorimeter. However, an
oscilloscope is as useless as tits on a boar hog for measuring
cleanliness of a SSB signal.

Well it's according to what you term clean. Harmonics no, unless

you

build or use a front end for this like the poor mans spectrum
analyzer, or one of the commercial add-on units. Over modulation,
hum, noise, regeneration, and parasitics can all be seen using a
standard scope.

But not SSB IMD.

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

Best,

Will

Hsu,

In reality, you can't compute the power output the transformer
is capable of that way. Bill Orr done a carry over from the
ARRL Handbook, or it was vice versa. The central core area in
square centimeters or sq inches is what determines the power
handling ability of the core, and the wire size determines the
power handling ability of the wire. You could have enough iron
in the core, but the wire be undersized, or you could have
heavy wire and a small core where a transformer could be close
to saturation. I started writing a complete section on this in
wikipedia that shows all the formulas used to calculate a
transformer size. There, you'll find the formula for power
output. You need to know the current density of the wire (J)
they ran the transformer at, or in how many circular mils per
ampere. That is generally somewhere between 750 to 1500 cir
mils per ampere. The higher the number, the more power it will
handle without getting to hot. A brick on the key amp should be
above 1000 cir mils per ampere, up to say around 1200. 1500 is
for one in a hot enviroment. You also need to know what the
flux density is they run the core at. 12 kilogauss is a good
number to start with, but if Hipersil, it's around 15-16
kilogauss. You also need to know the line frequency (f), the
window area (W) in square centimeters or inches (height x width),
and the central core size (a) in square centimeters or inches
(width x depth). That gives the following formula;

P = 0.707 x J x f x W x a x B

This is the way the transformer designer does it correctly.
The weight can only give a rough guess, nowhere near exact.

See;



Best,

Will


--- In ham_amplifiers@..., "Hsu" <Jbenson@...> wrote:

Hi ,
Could someone can tell me how much output power of TL922's HV

transformer?

I have an Bill Orr's Radio handbook, there is some curves ,in a

chart, transformer weght in pound VS amplifier power capcity in vary
service,but I do not know how to calculate transformer's output
power by its weight.

73! Hsu

Hi ,
Could someone can tell me how much output power of TL922's HV transformer?
I have an Bill Orr's Radio handbook, there is some curves ,in a chart, transformer weght in pound VS amplifier power capcity in vary service,but I do not know how to calculate transformer's output power by its weight.
73! Hsu

### why doesn't somebody offer an amp in kit form these
days ??? That would be the ticket. The end user would have a
better idea how to repair it... since he built it in the 1st
place ???
**

Hmm, as someone who has lost his butt in every possible business known
to man except ham radio <smarter than that, stupid as I am> it took me
about 4 uS to see problems with his idea.. The price of metal
stampings and machined parts that have been drilled and tapped,
cleaned, powder coated and baked, then shipped to your plant, will
take your breath away...The cost of the components is 98% of the
finished amp.. So, you are going to offer a kit amplifier that is
within 2% of the price of an assembled one... Guess what your sales
will be? And the ones that do sell will, ala Heathkit, require that
you have a repair department to take in the crippled amps that the
buyer swears is defective design and components because he doesn't
make mistakes, and he did NOT run it key down, untuned for 4 hours...
Then your tech finds stripped threads, broken components, things
backwards, partially melted tubes, etc., and you have the joy of
calling the customer and explaining that HE broke it and now it is on
his nickel for repairs...
After he gets done cursing you out in 3 tongues and threatening your
unborn children, you realize that this business is, "just sooo much
fun."...

denny / k8do

On Oct 24, 2006, at 5:18 PM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 24, 2006, at 1:35 AM, pentalab wrote:

### This sucks... and I don't like it one bit.

RICH SEZ... So use Matsushita/Panasonic MOFs instead of wire-wounds.

### Rich have u actually tried opening off one resistor [in a

one resistor per cap set up] and fired up the supply with a
small variac ??

RICH SEZ... Are you crazy? I was about 20-feet from where that

sucker exploded in the cal lab.

### Or should I not think about it... and hope my 24 x new

2500 > UF @ 450 V lytics don't got off like firecracker's
someday ??

RICH SEZ... To me, it sounded more like a jumbo cherry bomb.

Panasonic MOF resistors are pretty reliable.

### Flash ! with 4 x resistor's per cap... and one cut

loose. [assuming caps are no more than 75% of their v rating] The
one cap with the bad R will be almost maxed out.

RICH SEZ... That would work.

### 4 x resistor's in parallel = 25 K = lotsa heat per
cap. Probbaly 6-8 x resistor's.... each say 600-800K... all
in parallel... PER cap, would be the ultimate solution.....

then if anything opened up.... no chance of all ur caps blowing

up. The heat would be zip... per resistor.

ok problem solved.... now i can sleep

RICH SEZ.... But what if the sky falls?

later........ Jim VE7RF

########### Here's my problem Rich.... Those 2500 Uf @ 450 V CD
brand 10 A CCS ripple current rated caps I got NEW, by the case
load are listed at an unreal price tag.... like $100.00 EACH...
in single lot quantities. I have 72 of em... and will be using
em in groups of 24. I got em dirt cheap... they all tested
good, when checked on the bench. I would be just pissed if they
started exploding cuz of even the remotest chance of one resistor
lead opening.

So don't use WW resistors to equalize them.

### So... the real solution [aside from the usual 1 kv-6A safety
diode, rvs connected across eacg lytic] is to parallel 6 x 300 K
MOF resistors across EACH cap. [50 K for the paralled mess].

What is the V-rating and P rating of the 300k resistors?

If one ever opened... the voltage would only increase 20% on
that one cap. Total diss is 53 W. Each of the 144 resistor's
would only dissipate .37 w. Heck, with 6 x 150 K
resistors, Total diss rises to 106 W.... or a measely .74 watt
for each of the 144 resistor's.

### For a 8000 V [no load] supply... with 24 x caps..... normal V
per cap is 333 V [74% of the 450 V max rating]. With 6 x 300K /6
x 150 K resistor's across each cap.... and say one of the 6 opened
up.... V across that one cap will increase to 400 V.......well
within the 450 V rating of the cap....... end of problem.... end of
story.

### later...... Jim VE7RF






Yahoo! Groups Links

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

On Oct 24, 2006, at 2:49 PM, pentalab wrote:

--- In ham_amplifiers@..., Bill Turner <dezrat@...>
wrote:

ORIGINAL MESSAGE:

On Mon, 23 Oct 2006 00:20:30 -0000, "craxd" <craxd1@...>
wrote:

If a dip meter shows a
resonance, there is a resonance at its tuned frequency. Forget
reading the freq off the dial, simply couple it to a known

accurate

freq counter, it will show the truth if you want precision.

------------ REPLY FOLLOWS ------------

One needs to be careful with this. The typical single-tube or
single-transistor dip meter can be pulled considerably off the true
resonant frequency if coupling is very tight to a high-Q circuit.

Just

physically move the dip meter away far enough so the dip is barely
perceptible and the accuracy will improve greatly.

If you have used a dip meter much, you have no doubt had the
experience of tuning slowly across the dip, and as you continue

tuning

have the dip suddenly disappear as the pulling effect disappears.
Loose coupling will prevent this from happening.

### Highly agreed. Loose coupling is as good as it gets.... for
acuracy anyway. Mike Stahl, K6MYC warned me about this 25 yrs
ago.... he didn't trust em.. when tweaking yagi's.... I wouldn't
either.

According to a friend who loaned him a dipmeter, he did not realize that a plug-in coil had to be inserted to make it work.

### For a real laff.... I bought the "mating" grid dip osc
coils for my MFJ-259 analyzer. Two coils cover the entire
spectrum. I can't grid dip ANYTHING with em... even simple
stuff.. like a coil in parallel with a cap... on the test bench.
Then I find out nobody else can grid dip anything either! Then Rauch
sez they don't really work. They still don't. It was
suggested not to buy the optional coil(s).

With MFJ, $elling is the object, working is not

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

On Oct 24, 2006, at 9:05 PM, craxd wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 22, 2006, at 5:20 PM, craxd wrote:

Jim,

It's a wonder Tom didn't add a "by the way" saying, scopes and dip
meters are very inaccurate and should never be used. : ) At least

he

answered you by e-mail, he never would me.

He did not tell me this via e-mail. He said dipmeters were

worthless

during a discussion of various means of grounding grids after a
dipmeter measurement showed a result that contradicted his dicta
about grounding grids.

No, I meant I wouldn't doubt that he would have said
this to Jim.

If a scope is calibrated properly, or a dip meter the same, they
can't lie. They can only show you the truth.

That IS the problem here.

If a dip meter shows a
resonance, there is a resonance at its tuned frequency. Forget
reading the freq off the dial, simply couple it to a known

accurate

freq counter, it will show the truth if you want precision. A
calibrated scope can only show a waveform that it produces from

what

it sees at the input jack.

Correct. He didn't like the fact that an oscilloscope indicated a
worst-case potential in a SB-220 that was only about 1/3 of what

he

predicted it would be. This potential is on the verge of arcing

the

Tune-C, so even if the voltage tried to rise much higher, the cap
would zap and limit the voltage like a zener diode. The reason he
wanted the potential to be higher was to explain away what I said

was

parasitic arcing by the SB-220's occasional 110MHz oscillation.

The peak or peak to peak voltage one reads is exact,...

Porcine shampoo. I'm a guy who used to calibrate oscilloscopes.

A calibrated oscilloscope is one way power meters can be calibrated
and it's much faster than using a bomb-calorimeter. However, an
oscilloscope is as useless as tits on a boar hog for measuring
cleanliness of a SSB signal.

Well it's according to what you term clean. Harmonics no, unless you
build or use a front end for this like the poor mans spectrum
analyzer, or one of the commercial add-on units. Over modulation,
hum, noise, regeneration, and parasitics can all be seen using a
standard scope.

But not SSB IMD.

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

Sorry,

They do say what the form was changed to, I didn't see it the first
read. It now is made with a glass-based phenolic tubular core. That
would be similar to acting like micarta I would think.

Best,

Will


--- In ham_amplifiers@..., "craxd" <craxd1@...> wrote:

All,

Below is the link to the Oren Elliott website and the page with the
roller inductors. It doesn't say what the form material is, just

that

it's "newly redesigned".





Best,

Will

All,

Below is the link to the Oren Elliott website and the page with the
roller inductors. It doesn't say what the form material is, just that
it's "newly redesigned".





Best,

Will