Re: TL-922 tube filament voltage.
Ohmite
offers bolt down fractional value resistors in metal casings of
10 and 25 Watt values.
For a single 3-500Z dropping 0.5 Volt at 15.5 Amp requires an 0.17 Ohm resistor and will dissipate 7.25 Watts of power.?
Bolt the down under the chassis near the base of the tubes.?
This will place the resistors in the cooling air blast for the tubes.?
Use one resistor for each tube.
?
I have two Dale 0.02 Ω 25 Watt sitting here in front of me that I ordered from Mouser.?
I plan to use them in two amplifiers that have a single 3CX1500A7 tube in them.?
I too have high mains voltages that I use a Fluke meter to read.
?
73,
Dave, w6de
?
toggle quoted message
Show quoted text
From: ham-amplifiers@groups.io
<ham-amplifiers@groups.io> On Behalf Of Kim Herron via groups.io
Sent: 17 December, 2024 17:28
To: ham-amplifiers@groups.io
Subject: [ham-amplifiers] TL-922 tube filament voltage.
?
I've appreciated all the info that I've gotten on the Kenwood TL-922A and I've ordered the relay switching board from Harbach.? While I'm in there, I'd like to address the filament voltage.? I've looked? for info on how I might do that,
but I'm not finding what I want.? Is there an easy way to do this that has been done and I can get the docs on??? Any info would be appreciated.? BTW, I've had my electrical service here upgraded and my line voltage here measures around 250 VAC.? So that filament
voltage SHOULD be addressed.
|
Re: TL-922 tube filament voltage.
Lou, Good point on the meter. In the past if you talk to any electrical company about voltage they'll ask you "what meter are you using"? Bob W4JFA
On Tue, Dec 17, 2024 at 2:02?PM Louis Parascondola via <Gudguyham= aol.com@groups.io> wrote:
Updating a service really doesn’t raise the actual voltage coming into your house.? The only thing upgrading does is increase the potential current available to you.? With no load on your service the voltage should not have changed.? I would make sure you use a good meter to be sure your voltage is actually as high as 250! ? ?Generally line voltage of around 244 or less does not require any intervention on filament voltage adjustment.? Before I did anything to adjust filament voltage I would make definitely sure that at the pins the voltage was more than 5.3volts.? You definitely do not want less than 5 volts. ?
On Tuesday, December 17, 2024, 12:28 PM, Kim Herron <w8zv@...> wrote: Hi All,
?
I've appreciated all the info that I've gotten on the Kenwood TL-922A and I've ordered the relay switching board from Harbach.? While I'm in there, I'd like to address the filament voltage.? I've looked? for info on how I might do that, but I'm not finding what I want.? Is there an easy way to do this that has been done and I can get the docs on??? Any info would be appreciated.? BTW, I've had my electrical service here upgraded and my line voltage here measures around 250 VAC.? So that filament voltage SHOULD be addressed.
?
Thanks!!
--
Kim Herron W8ZV
|
Re: TL-922 tube filament voltage.
Updating a service really doesn’t raise the actual voltage coming into your house. ?The only thing upgrading does is increase the potential current available to you. ?With no load on your service the voltage should not have changed. ?I would make sure you use a good meter to be sure your voltage is actually as high as 250! ? ?Generally line voltage of around 244 or less does not require any intervention on filament voltage adjustment. ?Before I did anything to adjust filament voltage I would make definitely sure that at the pins the voltage was more than 5.3volts. ?You definitely do not want less than 5 volts. ?
On Tuesday, December 17, 2024, 12:28 PM, Kim Herron <w8zv@...> wrote: Hi All,
?
I've appreciated all the info that I've gotten on the Kenwood TL-922A and I've ordered the relay switching board from Harbach.? While I'm in there, I'd like to address the filament voltage.? I've looked? for info on how I might do that, but I'm not finding what I want.? Is there an easy way to do this that has been done and I can get the docs on??? Any info would be appreciated.? BTW, I've had my electrical service here upgraded and my line voltage here measures around 250 VAC.? So that filament voltage SHOULD be addressed.
?
Thanks!!
--
Kim Herron W8ZV
w8zv@...
|
TL-922 tube filament voltage.
Hi All,
?
I've appreciated all the info that I've gotten on the Kenwood TL-922A and I've ordered the relay switching board from Harbach.? While I'm in there, I'd like to address the filament voltage.? I've looked? for info on how I might do that, but I'm not finding what I want.? Is there an easy way to do this that has been done and I can get the docs on??? Any info would be appreciated.? BTW, I've had my electrical service here upgraded and my line voltage here measures around 250 VAC.? So that filament voltage SHOULD be addressed.
?
Thanks!!
--
Kim Herron W8ZV
w8zv@...
|
Re: Smoker contamination removal (chemicals not to use)
FYI:
?
"WARNING: Never mix ammonia with bleach. This causes the release of toxic chlorine gas, which can be deadly."
?
Read ingredients of the products you are mixing.? If they have the above in any amount don't mix.
?
Dale, K9VUJ
|
Re: Smoker contamination removal
It’s not worth the effort to eliminate the nicotine covering on any radio, despite the radio’s value.? Your life is worth more. ? If you can return it if bought, do so.? If not trash it.? I’ve done this on many over the years.? The STINK will come back despite most all efforts, but reduced. ? The only method I found acceptable was the aggressive dish washer mode.? Killed half the radios I tried in it after removing ALL susceptible parts. ? This was only on “boat anchor” rigs.? Not sure what would happen with a more modern rig.? Probably kill it. ? -Chuck K1KW ? ? ? ? ?
toggle quoted message
Show quoted text
From: ham-amplifiers@groups.io [mailto:ham-amplifiers@groups.io] On Behalf Of Don Roden
Sent: Saturday, December 14, 2024 1:23 PM
To: ham-amplifiers@groups.io
Subject: Re: [ham-amplifiers] Smoker contamination removal? "Scrubbing Bubbles" will remove nicotine from metal and paint. Don W4DNR? On 2024-12-14 12:18 pm, Kim Herron wrote: That type of thing happens when you inadvertently mix an ammonia based cleaner with a chlorine based cleaner. You? get the same kind of gas that was used on? troops during WW 1.? Ain't good.? Even crap that's marketed to be used as a janitorial product can really screw you up.? I have a permanently damaged set of lungs, courtesy of USPS, because the floor cleaner they use makes people sick and mixed at high concentrations, it's VERY bad.? Don't ask how I know.? You don't recover from what I have. On Saturday, December 14, 2024 at 01:06:43 PM EST, Michael <ironcoder@...> wrote: This is an important caution below from Kim. I did mix cleaners together for a difficult cleaning. It hurt my lungs and put me in bed for a day. I did recover. I realized I was being poisoned before it permanently damaged me or killed me. Michael On 12/14/2024 11:59 AM, Kim Herron wrote: Just a caution here.? Be VERY careful about what you mix together.? It's very easy to poison yourself from a BAD reaction of the chemicals.? Just a heads up for others.? Personally I've always used Dawn dishwashing detergent in my ultrasonic cleaner.? It works just fine.? On Saturday, December 14, 2024 at 11:34:14 AM EST, Technotronic Dimensions <steve@...> wrote: Latest photo of the chassis as I am removing and cleaning each individual Just took the top bread slicer out and I have a seperate plastic container I will fill with the Fan-monia and let it soak in there a while, then I pick it up and shake it around so the stuff bubbles and does further cleaning, and repeat. Seems to loosen alot of not all the niccotine sludge. I had to suppliment the Fantastick with some stuff Wallmart sells called Purple Power, seems to be a general purpose degreaser but sold in a larger container. Along the way I found a doorknob cap had broke or maybe been defective from the factory and will have to order a new one. I know from past experience niccotine is EXTEMELY ignitable and with this amp delivering 1500W RF power with I believe 2800VDC as the plate supply, the fact its everywhere left me no choice but to be as picky as possible to get 95% or more of the amp clean. The blower fan is still in there and its loaded with the stuff. Technotronic Dimensions, VT [USA]
|
Re: Smoker contamination removal
Good safety info reminders, thank you.
Meanwhile here is #2 bread slicer, before and after.
Soon as it was immersed, there was a tar film that appeared in the surface
near the bubbles, it almost instantly strips the tar right off.
I went over it with a new paint brush to get any tougher more stubborn spots
off, but I think the insides of the slicers got hit with not a lot of tar and it came off fast
but I will be inspecting it closer with a mag lamp and flashlight.
This is 66% Purple Power and 33% Lemon Amonia.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
toggle quoted message
Show quoted text
----- Original Message ----- From: "Michael" <ironcoder@...> To: <ham-amplifiers@groups.io> Sent: Saturday, December 14, 2024 1:06 PM Subject: Re: [ham-amplifiers] Smoker contamination removal This is an important caution below from Kim. I did mix cleaners together
for a difficult cleaning. It hurt my lungs and put me in bed for a day.
I did recover. I realized I was being poisoned before it permanently
damaged me or killed me.
Michael
On 12/14/2024 11:59 AM, Kim Herron wrote:
Just a caution here. Be VERY careful about what you mix together.
It's very easy to poison yourself from a BAD reaction of the
chemicals. Just a heads up for others. Personally I've always used
Dawn dishwashing detergent in my ultrasonic cleaner. It works just fine.
Kim Herron W8ZV kim.herron@... 1-616-677-3706
On Saturday, December 14, 2024 at 11:34:14 AM EST, Technotronic
Dimensions <steve@...> wrote:
Latest photo of the chassis as I am removing and cleaning each individual
assembly.
Just took the top bread slicer out and I have a seperate plastic
container I
will fill with the Fan-monia
and let it soak in there a while, then I pick it up and shake it
around so
the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all the niccotine sludge.
I had to suppliment the Fantastick with some stuff Wallmart sells called
Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
Along the way I found a doorknob cap had broke or maybe been defective
from
the factory and will have to order a new one.
I know from past experience niccotine is EXTEMELY ignitable and with this
amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the fact its everywhere left me no
choice but to be as picky as possible
to get 95% or more of the amp clean.
The blower fan is still in there and its loaded with the stuff.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
|
Re: Smoker contamination removal
I know of MEK, its very brutal...a rag with some on it
will strip paint immediately off metal with only one wipe.
I dont think its wise to be using that in our trade, way too powerful.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
toggle quoted message
Show quoted text
----- Original Message -----
From: "HaL Mandel via groups.io" <hmandel@...>
To: <ham-amplifiers@groups.io>
Sent: Saturday, December 14, 2024 1:22 PM
Subject: Re: [ham-amplifiers] Smoker contamination removal
In a recent Shure fatboy rebuild from 1941 and 1943 the re-plating of
the zinc frames were called for, but it was up to me first to get rid of years
of nicotine build-up from chain-smoking radio broadcast announcers,
close-talking and leaving their smelly shpit in and on the mic elements.
(Cigar smokers invariably spit tiny chunks into the grills.)
The mics were both BC types with three or four layers of cloth and
fine copper metal screen in between, so they did a great job of collecting.
All the inside components were trashed. The mic elements and magnets,
floating on the springs, were utterly gone. The springs, not stainless or phosphor
bronze, crumbled into a primordial ooze that turned into a miniature
coal mine of solidified tar.
After getting all the screws and parts out, the mic shells were boiled
in a mixture of kerosene and Methyl Ethyl Ketone using a boiling jacket
and a small tub from a lab bench. The last material to let go was
the contact cement globs adhering the inside fabric shells and
screens to the castings.
The solvents were replaced three times during the 48 hour process, and
each time save the last, smelled like an elevator with cigar smokers
stuck inside it. I felt like coughing myself. You know BC mics had
cough buttons, yes? No wonder. I could almost feel the congestion
building up. I started out in BC engineering as a studio tech and
you know who was customarily assigned mic chores, which were
especially odious when having to deal with 77's with their HV supplies
melting down from goo in the ribbons.
Hal Mandel
W4HBM
|
Re: Smoker contamination removal
"Scrubbing Bubbles" will remove nicotine from metal and paint.
Don W4DNR?
toggle quoted message
Show quoted text
On 2024-12-14 12:18 pm, Kim Herron wrote:
That type of thing happens when you inadvertently mix an ammonia based cleaner with a chlorine based cleaner.
You? get the same kind of gas that was used on? troops during WW 1.? Ain't good.? Even crap that's marketed to be used as a janitorial product can really screw you up.? I have a permanently damaged set of lungs, courtesy of USPS,
because the floor cleaner they use makes people sick and mixed at high concentrations, it's VERY bad.? Don't ask how I know.? You don't recover from what I have.
?
Kim Herron W8ZV kim.herron@... 1-616-677-3706
?
?
On Saturday, December 14, 2024 at 01:06:43 PM EST, Michael <ironcoder@...> wrote:
?
?
This is an important caution below from Kim. I did mix cleaners together for a difficult cleaning. It hurt my lungs and put me in bed for a day. I did recover. I realized I was being poisoned before it permanently damaged me or killed me.
Michael
On 12/14/2024 11:59 AM, Kim Herron wrote:
Just a caution here.? Be VERY careful about what you mix together.? It's very easy to poison yourself from a BAD reaction of the chemicals.? Just a heads up for others.? Personally I've always used Dawn dishwashing detergent in my ultrasonic cleaner.? It works just fine.?
?
?
?
On Saturday, December 14, 2024 at 11:34:14 AM EST, Technotronic Dimensions <steve@...> wrote: ?
?
?
Latest photo of the chassis as I am removing and cleaning each individual
assembly.
?
Just took the top bread slicer out and I have a seperate plastic container I
will fill with the Fan-monia
and let it soak in there a while, then I pick it up and shake it around so
the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all the niccotine sludge.
?
I had to suppliment the Fantastick with some stuff Wallmart sells called
Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
?
Along the way I found a doorknob cap had broke or maybe been defective from
the factory and will have to order a new one.
?
I know from past experience niccotine is EXTEMELY ignitable and with this
amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the fact its everywhere left me no
choice but to be as picky as possible
to get 95% or more of the amp clean.
?
The blower fan is still in there and its loaded with the stuff.
?
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
?
?
?
?
?
?
|
Re: Smoker contamination removal
In a recent Shure fatboy rebuild from 1941 and 1943 the re-plating of
the zinc frames were called for, but it was up to me first to get rid of years
of nicotine build-up from chain-smoking radio broadcast announcers,
close-talking and leaving their smelly shpit in and on the mic elements.
?
(Cigar smokers invariably spit tiny chunks into the grills.)
?
The mics were both BC types ?with three or four layers of cloth and
fine copper metal screen in between, so they ?did a great job of? collecting.
?
All the inside components were trashed. The mic elements and magnets,
floating on the springs, were utterly gone. The springs, not stainless or phosphor
bronze, crumbled into a primordial ooze that turned into a miniature
coal mine of solidified tar.
?
After getting all the screws and parts out, the mic shells were boiled
in a mixture of kerosene and Methyl Ethyl Ketone using a boiling jacket
and a small tub from a lab bench. The last material to let go was
the contact cement globs ?adhering the inside fabric shells and
screens to the castings.
?
The solvents were replaced three times during the 48 hour process, and
each time save the last, smelled like an elevator with cigar smokers
stuck inside it. I felt like coughing myself. You know BC mics had
cough buttons, yes?? No wonder. I could almost feel the congestion
building up. I started out in BC engineering as a studio tech and
you know who was customarily assigned mic chores, which were
especially odious when having to deal with 77’s with their HV supplies
melting down from goo in the ribbons.
?
Hal Mandel
W4HBM
|
Re: Smoker contamination removal
That type of thing happens when you inadvertently mix an ammonia based cleaner with a chlorine based cleaner. You get the same kind of gas that was used on? troops during WW 1.? Ain't good.? Even crap that's marketed to be used as a janitorial product can really screw you up.? I have a permanently damaged set of lungs, courtesy of USPS, because the floor cleaner they use makes people sick and mixed at high concentrations, it's VERY bad.? Don't ask how I know.? You don't recover from what I have.
Kim Herron W8ZV kim.herron@... 1-616-677-3706
On Saturday, December 14, 2024 at 01:06:43 PM EST, Michael <ironcoder@...> wrote:
This is an important caution
below from Kim. I did mix cleaners together for a difficult
cleaning. It hurt my lungs and put me in bed for a day. I did
recover. I realized I was being poisoned before it permanently
damaged me or killed me.
Michael
On 12/14/2024 11:59 AM, Kim Herron
wrote:
Just a caution here.? Be
VERY careful about what you mix together.? It's very easy to
poison yourself from a BAD reaction of the chemicals.? Just
a heads up for others.? Personally I've always used Dawn
dishwashing detergent in my ultrasonic cleaner.? It works
just fine.?
On Saturday, December 14, 2024 at 11:34:14 AM EST,
Technotronic Dimensions
<steve@...> wrote:
Latest photo of the chassis as I am removing
and cleaning each individual
assembly.
Just took the top bread slicer out and I have
a seperate plastic container I
will fill with the Fan-monia
and let it soak in there a while, then I pick
it up and shake it around so
the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all
the niccotine sludge.
I had to suppliment the Fantastick with some
stuff Wallmart sells called
Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
Along the way I found a doorknob cap had
broke or maybe been defective from
the factory and will have to order a new one.
I know from past experience niccotine is
EXTEMELY ignitable and with this
amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the
fact its everywhere left me no
choice but to be as picky as possible
to get 95% or more of the amp clean.
The blower fan is still in there and its
loaded with the stuff.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
|
Re: Smoker contamination removal
This is an important caution
below from Kim. I did mix cleaners together for a difficult
cleaning. It hurt my lungs and put me in bed for a day. I did
recover. I realized I was being poisoned before it permanently
damaged me or killed me.
Michael
On 12/14/2024 11:59 AM, Kim Herron
wrote:
toggle quoted message
Show quoted text
Just a caution here.? Be
VERY careful about what you mix together.? It's very easy to
poison yourself from a BAD reaction of the chemicals.? Just
a heads up for others.? Personally I've always used Dawn
dishwashing detergent in my ultrasonic cleaner.? It works
just fine.?
On Saturday, December 14, 2024 at 11:34:14 AM EST,
Technotronic Dimensions
<steve@...> wrote:
Latest photo of the chassis as I am removing
and cleaning each individual
assembly.
Just took the top bread slicer out and I have
a seperate plastic container I
will fill with the Fan-monia
and let it soak in there a while, then I pick
it up and shake it around so
the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all
the niccotine sludge.
I had to suppliment the Fantastick with some
stuff Wallmart sells called
Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
Along the way I found a doorknob cap had
broke or maybe been defective from
the factory and will have to order a new one.
I know from past experience niccotine is
EXTEMELY ignitable and with this
amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the
fact its everywhere left me no
choice but to be as picky as possible
to get 95% or more of the amp clean.
The blower fan is still in there and its
loaded with the stuff.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
|
Re: Smoker contamination removal
Just a caution here.? Be VERY careful about what you mix together.? It's very easy to poison yourself from a BAD reaction of the chemicals.? Just a heads up for others.? Personally I've always used Dawn dishwashing detergent in my ultrasonic cleaner.? It works just fine.?
Kim Herron W8ZV kim.herron@... 1-616-677-3706
On Saturday, December 14, 2024 at 11:34:14 AM EST, Technotronic Dimensions <steve@...> wrote:
Latest photo of the chassis as I am removing and cleaning each individual
assembly.
Just took the top bread slicer out and I have a seperate plastic container I
will fill with the Fan-monia
and let it soak in there a while, then I pick it up and shake it around so
the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all the niccotine sludge.
I had to suppliment the Fantastick with some stuff Wallmart sells called
Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
Along the way I found a doorknob cap had broke or maybe been defective from
the factory and will have to order a new one.
I know from past experience niccotine is EXTEMELY ignitable and with this
amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the fact its everywhere left me no
choice but to be as picky as possible
to get 95% or more of the amp clean.
The blower fan is still in there and its loaded with the stuff.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
|
Re: Smoker contamination removal
Latest photo of the chassis as I am removing and cleaning each individual
assembly.
Just took the top bread slicer out and I have a seperate plastic container I will fill with the Fan-monia
and let it soak in there a while, then I pick it up and shake it around so the stuff bubbles and does further cleaning,
and repeat. Seems to loosen alot of not all the niccotine sludge.
I had to suppliment the Fantastick with some stuff Wallmart sells called Purple Power, seems to be a general purpose
degreaser but sold in a larger container.
Along the way I found a doorknob cap had broke or maybe been defective from the factory and will have to order a new one.
I know from past experience niccotine is EXTEMELY ignitable and with this amp delivering 1500W RF power with
I believe 2800VDC as the plate supply, the fact its everywhere left me no choice but to be as picky as possible
to get 95% or more of the amp clean.
The blower fan is still in there and its loaded with the stuff.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
|
Thanks for sending twice.
?
toggle quoted message
Show quoted text
From: ham-amplifiers@groups.io
<ham-amplifiers@groups.io> On Behalf Of Alan - W5ARM via groups.io
Sent: 12 December, 2024 9:03 PM
To: ham-amplifiers@groups.io
Subject: Re: [ham-amplifiers] HV Wire
?
On Sun, Nov 24, 2024 at 01:10 PM, Walter wrote:
Hey... just a quick FYI (for future use):
When posting web links, everything AFTER the question mark (?) in the destination URL, can be removed. That info is (generally) specific to you, your browser, your login, etc.
It is NOT needed nor required to access the target webpage.
?Your link should have looked like this:
|
Thanks for the heads up, Alan
?
toggle quoted message
Show quoted text
From: ham-amplifiers@groups.io
<ham-amplifiers@groups.io> On Behalf Of Alan - W5ARM via groups.io
Sent: 12 December, 2024 9:03 PM
To: ham-amplifiers@groups.io
Subject: Re: [ham-amplifiers] HV Wire
?
On Sun, Nov 24, 2024 at 01:10 PM, Walter wrote:
Hey... just a quick FYI (for future use):
When posting web links, everything AFTER the question mark (?) in the destination URL, can be removed. That info is (generally) specific to you, your browser, your login, etc.
It is NOT needed nor required to access the target webpage.
?Your link should have looked like this:
|
Mcmaster carrs prices are absurd....and are? per foot !!?
I used rolls of belden 10 kv test prod wire.? It comes in red or black.? 18 ga stranded...and silicone rubber...and flexible as spaghetti.? ? Rated for 10 kv and aprx .1988" OD.? I would not use it externally though....... it's prone to nicks on anything. And it will also self seal.?
On the hb amp, for EXTERNAL? B+? ?between racks,? I gave up on connectors and hv wire.? ? Just used RG-393, since I have a 200' roll of it.? ?I used those cinch down fittings, that are used for strain relief for cables.? Also called cable glans.? U can even get em in sweeping right angles.?
Inside the cabinet, the braid of the RG-213 / RG-393 is peeled way back, like 2"- 3"...then chopped off.? ?Perhaps? 1/2" to 3/4" of braid exposed. (and 2-3"? of center conductor and dielectric).? Copper strap is wrapped around the exposed braid. Machine screwed and soldered.? ?Other end of the same copper strap is machine screwed to the chassis.? Center conductor gets a crimped and soldered lug...and goes to B+.? The cable glans provides for strain relief.? A ty-rap can be placed around the 213 / 393 outer jacket, for extra strain relief.?
Same rigmarole at the other end of the coax on next rack cabinet.? Then the B+ is on the center conductor, and the braid is 100% bonded to the chassis at each end of the cable.? ?Then there is no way to kill urself.?
RG-59U? will easily pass a 30 kv hi-pot test.? 213 U will pass a 50 kv hi-pot test...and 393 teflon coax would be through the stratosphere.? ?213-u was used in some labs to handle 50 kvdc on a daily basis.?
With coax, the issue is not the dielectric? HV standoff...... it's how far back u peel the braid at each end.? ?That's called....'surface creep' ....and typ, 1" per 10 kv is recommended.?
On that 6700 vdc supply I built years ago, it used oil caps.....and was also wired externally to a bank of 20x 2000uf lytics.? ?I used Belden? 10 kv test prod wire....and new millens at each end...to get from small rack, to small mating box above it.? ? ? I got my forearm close to the B+ external wire......and all the hair on my forearm stuck straight out !? That freaked me out.?
Inside the HV supply / RF deck, anything will work as long as its HV rated.?
You can get proper HV connectors for 213 / 393 coax.? They look almost identical to a PL-259 / SO-239 on the outside, on the inside, they have the tubular insulation that is 2-3-4" long for 10-15-20 kv rating.? ?They are stupid expensive, but are abt the only real deal HV connector made for coax.?
At the telco I worked at, the electrical sub contractor who looked after the 450 kva / 2000 kva vault xfmr, had a 0-100 kv? hi-pot tester.? ?I don't have access to this stuff since being retired.? ? Never did get to test some 393 teflon coax.?
?
|
On Sun, Nov 24, 2024 at 01:10 PM, Walter wrote:
Hey... just a quick FYI (for future use):
When posting web links, everything AFTER the question mark - and including the question mark (?) - in the destination URL, can be removed (i.e., deleted). That info is [generally] specific to you, your browser, your login, etc.
?
It is NOT needed nor required to access the target webpage.
?
?Your link should have looked like this:
?
?
//
73,
~Alan
|
McMaster-Carr sells high-quality HV wire, in several sizes and volt-ratings:
?
HERE:
?
--
73,
~Alan
|
Good quality coax. With SHV connectors.
|
Bob
Dale, K9VUJ
Technotronic Dimensions
HaL Mandel
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