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Re: US screws - name

 


Re: US screws - name

 

开云体育

I have lost my 10mm socket.

W4DNR


On 2025-03-20 2:33 am, Steve wrote:

On 3/19/2025 11:06 PM, Fran?ois via groups.io wrote:

Surface area =? length x width.? 27 1/4"? = 27.25"?
5/16 = .315"

7/8" = .875"?

etc, etc.

?

Ah, ok.

You convert the mixed numbers into decimals and you get "? (square inches).

?

5/16 = .315"

7/8" = .875"

?

Do you have these correspondences in your head like the multiplication tables?

Many of them, I do, yes. Many of us who have done very much "homebrewing" of chassis, panels, etc. through the years have sorta memorized those fractions of inches. At the least, you will almost always find charts posted on our workshops showing those fractions in large print so we can easily read it across the shop (when we can't remember one right off the bat). And yes, we also sometimes more-formally call our system of inches and feet the "imperial" measurement system; although more often, we call it the SAE system, which stands for Society of Automotive Engineers, which in years past, used to "champion" the use of inches and feet especially in American automobiles.

Also, approximating converting mm to inches isn't very difficult: just remember that 1 mm is just a little bit less than 0.04" (0.039371", to be more exact). Therefore, you're almost always "close enough" to just use 0.040" as the length of 1 mm. The easy way to imagine 0.04" is that it's just a little bit wider than the gap of olden time automotive spark plugs used to be set at (which was almost always 0.032", sometimes as wide as 0.038"; but more recently with the use of high performance electronic ignition systems, 0.045" or even 0.060").

Thus, 3.5 mm is 3 times 0.04", plus half of another 0.04" or 0.02"; and so 3.5mm = 0.12 + 0.02 = a total of about 0.14", compared to 0.13779535" if you use all the least significant digits of the exact measurement. You would only be off by a bit more than 0.002" which is less than the thickness of a sheet of tissue paper. As the saying goes, "close enough for government work" 8-)

It's fairly easy to imagine 3mm since that's just a little bit less than 1/8" (which is actually 0.125").

Similarly, 1 inch is 2.54cm; just to get in the ballpark, simply use 2.5. Thus, 20" = 20 x 2.5 or 50cm, then that little bit extra is 20 x 0.04 = 0.8. And so adding all that together, you get 50.8cm.

Converting meters in inches becomes more difficult since you have a much larger portion of a whole to account for, 39.38" = 1 meter; that 0.38 becomes significant and makes it a bit more difficult just to "guess" the total. Typically, we might "guess" and add a third plus a bit more for that 0.38. Or sometimes simply multiply by 39.4 instead of 39.38, then subtract just a tiny bit.

For another but wholly different type of "approximate-guesswork": say you want to know approximately how long a hunk of coax is. First you estimate the diameter of the cable when rolled up; then count the number of turns in the coil of cable, and simply multiply that times 3, then add in a bit more (because circumference = diameter times Pi, or 3.14).

Say you have 30 turns of coax in a coil that's roughly 1 foot in diameter; then it's "at least" 30 times 3 feet long = 90 feet, more probably about 95 feet or so altogether when you add in that portion needed for the 0.14. If you cheat and use your calculator instead, it says your coil of cable is actually 94.2 feet long: once again, "close nuff fer guvmint work" 8-).

Steve K0XP


Re: US screws - name

 

开云体育

On 3/19/2025 11:06 PM, Fran?ois via groups.io wrote:

Surface area =? length x width.? 27 1/4"? = 27.25"?
5/16 = .315"

7/8" = .875"?

etc, etc.

?

Ah, ok.

You convert the mixed numbers into decimals and you get "? (square inches).

?

5/16 = .315"

7/8" = .875"

?

Do you have these correspondences in your head like the multiplication tables?

Many of them, I do, yes. Many of us who have done very much "homebrewing" of chassis, panels, etc. through the years have sorta memorized those fractions of inches. At the least, you will almost always find charts posted on our workshops showing those fractions in large print so we can easily read it across the shop (when we can't remember one right off the bat). And yes, we also sometimes more-formally call our system of inches and feet the "imperial" measurement system; although more often, we call it the SAE system, which stands for Society of Automotive Engineers, which in years past, used to "champion" the use of inches and feet especially in American automobiles.

Also, approximating converting mm to inches isn't very difficult: just remember that 1 mm is just a little bit less than 0.04" (0.039371", to be more exact). Therefore, you're almost always "close enough" to just use 0.040" as the length of 1 mm. The easy way to imagine 0.04" is that it's just a little bit wider than the gap of olden time automotive spark plugs used to be set at (which was almost always 0.032", sometimes as wide as 0.038"; but more recently with the use of high performance electronic ignition systems, 0.045" or even 0.060").

Thus, 3.5 mm is 3 times 0.04", plus half of another 0.04" or 0.02"; and so 3.5mm = 0.12 + 0.02 = a total of about 0.14", compared to 0.13779535" if you use all the least significant digits of the exact measurement. You would only be off by a bit more than 0.002" which is less than the thickness of a sheet of tissue paper. As the saying goes, "close enough for government work" 8-)

It's fairly easy to imagine 3mm since that's just a little bit less than 1/8" (which is actually 0.125").

Similarly, 1 inch is 2.54cm; just to get in the ballpark, simply use 2.5. Thus, 20" = 20 x 2.5 or 50cm, then that little bit extra is 20 x 0.04 = 0.8. And so adding all that together, you get 50.8cm.

Converting meters in inches becomes more difficult since you have a much larger portion of a whole to account for, 39.38" = 1 meter; that 0.38 becomes significant and makes it a bit more difficult just to "guess" the total. Typically, we might "guess" and add a third plus a bit more for that 0.38. Or sometimes simply multiply by 39.4 instead of 39.38, then subtract just a tiny bit.

For another but wholly different type of "approximate-guesswork": say you want to know approximately how long a hunk of coax is. First you estimate the diameter of the cable when rolled up; then count the number of turns in the coil of cable, and simply multiply that times 3, then add in a bit more (because circumference = diameter times Pi, or 3.14).

Say you have 30 turns of coax in a coil that's roughly 1 foot in diameter; then it's "at least" 30 times 3 feet long = 90 feet, more probably about 95 feet or so altogether when you add in that portion needed for the 0.14. If you cheat and use your calculator instead, it says your coil of cable is actually 94.2 feet long: once again, "close nuff fer guvmint work" 8-).

Steve K0XP


Re: US screws - name

 

开云体育

Surface area =? length x width.? 27 1/4"? = 27.25"?
5/16 = .315"

7/8" = .875"?

etc, etc.

?

Ah, ok.

You convert the mixed numbers into decimals and you get "? (square inches).

?

5/16 = .315"

7/8" = .875"

?

Do you have these correspondences in your head like the multiplication tables?

?

5

7

16

8

0,3125

0,875

?

--

F1AMM

Fran?ois

De la part de Jim VE7RF via groups.io
贰苍惫辞测é?: jeudi 20 mars 2025 05:15


Re: US screws - name

 

Surface area =? length x width.? 27 1/4"? = 27.25"?
5/16 = .315"
7/8" = .875"?
etc, etc.


12 KW CCS ON 160-15M....USING THE 3CX-6000A7..... PART 23

 

12 KW CCS ON 160-15M....USING THE 3CX-6000A7..... PART 23

Here, the 7.0 vac @ 80 amp CCS? ?fil xfmr and the mating? 4 amp,? 240 vac variac is installed.? ?Along with the pair of 100 amp? CCS rated....'supercon connectors'.? ?4 ga wire? from supercon connectors? over to RF deck...where another pair of 100 amp connectors will be installed.? ?The supercon 100 amp connectors use? 5/16" studs on the back end. (The larger 250 amp version uses? 1/2"? studs? They also come in a 50 amp version, using 1/4-28 studs......and also a 25 amp version, using 10-32 studs).? The power supply is progressing slowly due to time constraints.? Fil voltage will be measured at the cathode terminals....via a small RF choke in each leg.? On new / rebuilt tubes, it's run at rated V? for the 1st 200 hrs. Emission increases during the 1st 200 hrs, then levels off.? ?After 200 hrs, the fil V is reduced by 10 %.... like down to 6.3 vac.


Re: US screws - name

 

开云体育

In Canada, we use both SAE and Metric. […] However,? cars are all metric, including cars built in the usa.?

When you mix the two, it must be terrible. And yet the US'OM counts wavelengths in meters.

?

How do you calculate a surface area when the dimensions are like 27 1/4 inches?

?

Strange about cars. At home, I have gardening equipment with Briggs & Stratton engines; they're US screws. In France, they're called "imperial size."

?

It's a pain, and even then, when it comes to screws, the choice is limited, but when you use tubes...

--

F1AMM

Fran?ois

De la part de Jim VE7RF via groups.io
贰苍惫辞测é?: mardi 18 mars 2025 20:58


Re: US screws - name

 

In Canada, we use both SAE and Metric.? I use strictly SAE for machine screws,? nuts and bolts, and hardware for ant stuff etc, etc.? ?I avoid metric like the plague.?
However,? cars are all metric, including cars built in the usa.?

Metric came out in Canada, after I had left school.? ?I still can't relate to it.? ? I have to mentally convert it for everything.? ?80 kmh ?? ?Oh, that's 51 mph, ok, I know how fast I'm going.? ?20C? is? 68F.... ok, now I know how warm / cold it is.? ?Fuel milage is? Liters per 100 km...(62 miles) ..... instead of miles per imperial / US gallon.?

?100 mm? = 10 cm =? aprx 4".? 25.4 mm = 1"? ? 1/4" = 6.35 mm.?

I asked my son one day to get me a short length of? 2x4.? ?(A 2x4? is a piece of wood that is 1.5"? thick x 3.5"? wide).? ?He comes back with a 12" square piece of? 1/2" thick plywood.? WTF ?? "What the hell are u doing"? ? He sez......' How many CM is that ? '? ?F#@K, I don't know Josh.? ? I wasn't abt to convert 1.5"? to cm....and ditto with 3.5"? to? cm.??


Re: CTR Engineering/W8JI Response?

 

Really ??

On 2025-03-16 09:06, Peter Voelpel wrote:
Read the question.
-----Original-Nachricht-----
Betreff: Re: [ham-amplifiers] CTR Engineering/W8JI Response?
Datum: 2025-03-16T12:18:34+0100
Von: "Amp Guy Llc" <kb1sel@...>
An: "[email protected]" <[email protected]>
We have more ??
And more to come
Will be around for a very long time, im 43
Eventually we will be winding plate chokes and selling parts for
Ameritron pa’s
On 2025-03-15 08:54, Steve wrote:
Harbach doesn't have the goodies he has.
On 3/15/2025 2:56 AM, Amp Guy Llc wrote:

FYI
Harbachelectronics.com items ship the next business day On
2025-03-15 00:56, Steve wrote:

For those who have ordered from CTR recently: how long did it take
to
receive a response? Also, I could not find anything on his web
site
regarding tax or shipping costs; I presume he states those in his
response, along with his desired payment method(s)?
TNX,
Steve K0XP
--
See my QRZ.com page at
Links:
------
[1] /g/ham-amplifiers/message/41084
[2] /mt/111713302/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5]
/g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
?


Re: CTR Engineering/W8JI Response?

 

Read the question.


-----Original-Nachricht-----
Betreff: Re: [ham-amplifiers] CTR Engineering/W8JI Response?
Datum: 2025-03-16T12:18:34+0100
Von: "Amp Guy Llc" <kb1sel@...>
An: "[email protected]" <[email protected]>

We have more ??

And more to come

Will be around for a very long time, im 43

Eventually we will be winding plate chokes and selling parts for
Ameritron pa’s





On 2025-03-15 08:54, Steve wrote:
Harbach doesn't have the goodies he has.
On 3/15/2025 2:56 AM, Amp Guy Llc wrote:

FYI

Harbachelectronics.com items ship the next business day On
2025-03-15 00:56, Steve wrote:

For those who have ordered from CTR recently: how long did it take
to
receive a response? Also, I could not find anything on his web
site
regarding tax or shipping costs; I presume he states those in his
response, along with his desired payment method(s)?

TNX,

Steve K0XP
--
See my QRZ.com page at


Links:
------
[1] /g/ham-amplifiers/message/41084
[2] /mt/111713302/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5]
/g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy




?


Re: US screws - name

 

开云体育

> It's? 6-32 hardware.? ?6-32 has a? .138" diameter thread (3.51 mm).? ? The 32 means it has 32 threads per inch.?

?

Thank you very much for the information. I'll be able to purchase the nuts.

?

In Canada, do you commonly use US or metric screws (like everyone else :)?

?

To answer, I circled the nut in the attached image.

--

F1AMM

Fran?ois

De la part de Jim VE7RF via groups.io
贰苍惫辞测é?: dimanche 16 mars 2025 12:38
_._,_._,_


Re: US screws - name

 

It's? 6-32 hardware.? ?6-32 has a? .138" diameter thread (3.51 mm).? ? The 32 means it has 32 threads per inch.?


Re: US screws - name

 

Are you referring to the screws that mount the tube sockets?? Common thread sizes are 6-32, 8-32 and 10-32 or 10-24 . Mike

On Sunday, March 16, 2025 at 05:32:41 AM EDT, Fran?ois via groups.io <18471@...> wrote:


Hello

?

On my Drake amplifier, I would like to install additional hardware using existing threaded rods (3-500Z support spacers). If I measure the thread diameter, I get a reading of 3.3 mm (1/7 inch). The existing nuts measure 6.1 mm (1/4 inch) across the flat.

?

Can you tell me the US thread size for this type of thread?

?

--

F1AMM

Fran?ois


Re: CTR Engineering/W8JI Response?

 

We have more ??

And more to come

Will be around for a very long time, im 43

Eventually we will be winding plate chokes and selling parts for Ameritron pa’s

On 2025-03-15 08:54, Steve wrote:
Harbach doesn't have the goodies he has.
On 3/15/2025 2:56 AM, Amp Guy Llc wrote:

FYI
Harbachelectronics.com items ship the next business day On
2025-03-15 00:56, Steve wrote:

For those who have ordered from CTR recently: how long did it take
to
receive a response? Also, I could not find anything on his web
site
regarding tax or shipping costs; I presume he states those in his
response, along with his desired payment method(s)?
TNX,
Steve K0XP
--
See my QRZ.com page at
Links:
------
[1] /g/ham-amplifiers/message/41084
[2] /mt/111713302/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy


US screws - name

 

开云体育

Hello

?

On my Drake amplifier, I would like to install additional hardware using existing threaded rods (3-500Z support spacers). If I measure the thread diameter, I get a reading of 3.3 mm (1/7 inch). The existing nuts measure 6.1 mm (1/4 inch) across the flat.

?

Can you tell me the US thread size for this type of thread?

?

--

F1AMM

Fran?ois


Re: Total insanity....500KW 11m amp being built.

 

Little mistakes at those Power Levels goes BOOOOOOMMMMMMM !


On Sat, Mar 15, 2025, 6:08?PM Mike Peace via <mike.peace=[email protected]> wrote:
Hi Jim,

Your're exactly right!??
i agree, the Only way is grid drive.??
Thanks for taking time do the math
and and expose the massive plate?
current on peaks.

Regardless, it's a crazy project but
we are getting to exercise our imagination
and exploring the limits of big steel tubes.

73's,
Mike?
VK6ADA

On Sat, Mar 15, 2025 at 7:47?PM Jim VE7RF via <jim.thom=[email protected]> wrote:
Mike, where are they gonna obtain a modulation xfmr ??? ? Per the? Eimac spec sheet for plate modulated AM,? ?the secondary of the modulation xfmr would have? 15 kvdc across it...and 23.4 amps? flowing through the sec of the modulation xfmr.? ?The 15 kv across the modulation xfmr will rvs in polarity.....and the sec of the mod xfmr is in series with the 15 kv? B+.? ? And that's just for 100%? positive modulation.

IE:? the B+ would? swing to? +30 kv? on positive mod peaks..... and down to 0 volts? on negative peaks.?

15 kv? @ 11.7 amps = 175.5 kw modulation xfmr.? ?At the crest of the positive modulation,? B+ on the anode? is now? 30 kv....and plate current is now double at 23.4 amps.?

Let's assume plate modulation is not happening any time soon.?

They shoulda just run it grid driven, for linear service? like on the spec sheet.? ?200 kw pep out, and 50 kw cxr......which? swings to 75 kw.? ?That's 25 kw of total swing....( 25 kw of? total sideband power)..., with just 12.5 kw into each sideband.?

Still a wasted effort.? The 3x6 amp puts out 12.5 kw pep on ssb.?


Re: Total insanity....500KW 11m amp being built.

 

Hi Jim,

Your're exactly right!??
i agree, the Only way is grid drive.??
Thanks for taking time do the math
and and expose the massive plate?
current on peaks.

Regardless, it's a crazy project but
we are getting to exercise our imagination
and exploring the limits of big steel tubes.

73's,
Mike?
VK6ADA

On Sat, Mar 15, 2025 at 7:47?PM Jim VE7RF via <jim.thom=[email protected]> wrote:
Mike, where are they gonna obtain a modulation xfmr ??? ? Per the? Eimac spec sheet for plate modulated AM,? ?the secondary of the modulation xfmr would have? 15 kvdc across it...and 23.4 amps? flowing through the sec of the modulation xfmr.? ?The 15 kv across the modulation xfmr will rvs in polarity.....and the sec of the mod xfmr is in series with the 15 kv? B+.? ? And that's just for 100%? positive modulation.

IE:? the B+ would? swing to? +30 kv? on positive mod peaks..... and down to 0 volts? on negative peaks.?

15 kv? @ 11.7 amps = 175.5 kw modulation xfmr.? ?At the crest of the positive modulation,? B+ on the anode? is now? 30 kv....and plate current is now double at 23.4 amps.?

Let's assume plate modulation is not happening any time soon.?

They shoulda just run it grid driven, for linear service? like on the spec sheet.? ?200 kw pep out, and 50 kw cxr......which? swings to 75 kw.? ?That's 25 kw of total swing....( 25 kw of? total sideband power)..., with just 12.5 kw into each sideband.?

Still a wasted effort.? The 3x6 amp puts out 12.5 kw pep on ssb.?


Re: Total insanity....500KW 11m amp being built.

 

Mike, where are they gonna obtain a modulation xfmr ??? ? Per the? Eimac spec sheet for plate modulated AM,? ?the secondary of the modulation xfmr would have? 15 kvdc across it...and 23.4 amps? flowing through the sec of the modulation xfmr.? ?The 15 kv across the modulation xfmr will rvs in polarity.....and the sec of the mod xfmr is in series with the 15 kv? B+.? ? And that's just for 100%? positive modulation.

IE:? the B+ would? swing to? +30 kv? on positive mod peaks..... and down to 0 volts? on negative peaks.?

15 kv? @ 11.7 amps = 175.5 kw modulation xfmr.? ?At the crest of the positive modulation,? B+ on the anode? is now? 30 kv....and plate current is now double at 23.4 amps.?

Let's assume plate modulation is not happening any time soon.?

They shoulda just run it grid driven, for linear service? like on the spec sheet.? ?200 kw pep out, and 50 kw cxr......which? swings to 75 kw.? ?That's 25 kw of total swing....( 25 kw of? total sideband power)..., with just 12.5 kw into each sideband.?

Still a wasted effort.? The 3x6 amp puts out 12.5 kw pep on ssb.?


SVHFS Presenters & Conference Update

 

Below is an update on the schedule of speakers and presentations for the Southeastern VHF Society Conference. The conference will be held at the Quality Inn at Exit #4 in Clarksville, TN April 4-5, 2025. This is an opportunity to meet other VHF+ enthusiasts, learn, exchange ideas, and have FUN. The $69 registration fee for the?conference is required, and it includes a 1 year membership in the SVHFS. Details are here:?. Advance registration?is highly recommended as the hotel requires a head count in order to prepare the food for the event. There will be door prizes given away at the banquet on Saturday evening. Feel free to contact me??via?email if you have any questions:?RobinK4IDC@....

Preliminary 2025 SVHFS Conference Schedule

Friday

8:00 AM Registration

9:00 Charles Osborne -K4CSO – RF Zero - 30 min

9:30 Robin Midgett – K4IDC – RF Zero 2 Meter Beacon- 30 min

10:00 Bob Lear – W4ZST Power Dividers and Cable Loops – 30 min

10:30 15 Minute Break

10:45 Mike Stipick – KC4RI – 5.7 GHz SDR Transceiver - 45 min

11:30 Bill Pence – Grid Square Locator – 30 min

12:00 PM Lunch - Steve and Sandra Kostro – Designing a Multi Band Transverter

1:15

2:00 Paul Wielozenski - K4PEW - VHF Nets – 30 min

2:30 Ben Lowe – Rover Radiators – 30 min

3:00 George Presley – 10 GHz Beacon – 30 min

4:00 Charles Osborne / Kent O’ Dell – 10GHz Antenna test Range - 30 min

5:00 Dinner –On your own

7:00 Swap Fest and Hospitality Suite

Saturday

9:00 AM Brian McCarthy – Lunar Rover Truck, 2.3GHz Amp – 1 hour

10:00 Peter Van Horne – KA6U - Moon Bounce Rover – 45 min

10:45 15 Minute Break

11:00 Chris Arthur - NV4B – 45 min

12:00 PM Lunch - On your own

1:30 Larry Cagle - K4WLO – Meteor Scatter with MSK144 - 45 min

2:15 SVHFS Business Meeting

3:00 – 5:00 Rover Round Up and 10GHz Antenna Range

6:00 Social Hour- Hotel Bar

7:00 Dinner Banquet followed by the Door Prize Extravaganza!?



Thanks,
Robin Midgett K4IDC


Re: CTR Engineering/W8JI Response?

 

开云体育

Harbach doesn't have the goodies he has.

On 3/15/2025 2:56 AM, Amp Guy Llc wrote:
FYI

Harbachelectronics.com items ship the next business day On 2025-03-15 00:56, Steve wrote:
For those who have ordered from CTR recently: how long did it take to
receive a response? Also, I could not find anything on his web site
regarding tax or shipping costs; I presume he states those in his
response, along with his desired payment method(s)?

TNX,

Steve K0XP









--
See my QRZ.com page at