Re: Ameritron Plate Chokes
There are? Russian 4?H roller inductors..
They are available at Dr. Alex, UR4LL:
?
?
73
Peter, DJ7WW
?
?
## merrit Arnold's wife and son now run RF parts.? One of the girls who works there tells me arnolds wife is a ...'real piece of work'.? ?I know other folks who wanted to buy 4x10 tubes..and that was another item they would not ship overseas.? Bonny has some bug up her rear end, about some items that should not be shipped outside of the usa...siting....'only should be sold in america'.? The small 0-4.4 uh roller coil ( 8 ga wire) was originally made by multronics.? ?Then Cardwell condenser co? bought out multronics...and the same roller coils in the RF parts site were indeed stamped...'Cardwell condenser Corp'.? ?Cardwell sold out to 'Viking'? ?( who owns the custom clothing line).? ?I just ordered 2 of the rollers? directly from Viking, no fuss, shipped fast.?
?
?
|
Re: Ameritron Plate Chokes
Thank you for this write up.
?
73,
Dave, w6de
?
toggle quoted message
Show quoted text
From: [email protected]
<[email protected]> On Behalf Of Jim VE7RF via groups.io
Sent: 18 February, 2024 17:22
To: [email protected]
Subject: Re: [ham-amplifiers] Ameritron Plate Chokes
?
On Sat, Feb 17, 2024 at 11:39 PM, Dave w6de wrote:
What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer available for export."
When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions.
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
##? No they don't.? I just recently bought 2 x of the ameritron chokes from? RF parts. ( 2-3 yrs ago).? ?ONLY on some selected items, ( and that choke is NOT one of em, as of 5 mins ago) will they refuse to ship outside the USA.? I had also ordered a pair
of 0-4.4 uh roller coils. RF parts would not export em.? I couldn't even get em shipped to a friend in the usa.? ?The only work around was to have a friend in the usa pay for em, and have em shipped to his usa address..... then re-send em to my address via
USPS. ..( that advice came from the girl in the office, not the owner, bonny)
?
## merrit Arnold's wife and son now run RF parts.? One of the girls who works there tells me arnolds wife is a ...'real piece of work'.? ?I know other folks who wanted to buy 4x10 tubes..and that was another item they would not ship overseas.? Bonny has
some bug up her rear end, about some items that should not be shipped outside of the usa...siting....'only should be sold in america'.? The small 0-4.4 uh roller coil ( 8 ga wire) was originally made by multronics.? ?Then Cardwell condenser co? bought out
multronics...and the same roller coils in the RF parts site were indeed stamped...'Cardwell condenser Corp'.? ?Cardwell sold out to 'Viking'? ?( who owns the custom clothing line).? ?I just ordered 2 of the rollers? directly from Viking, no fuss, shipped fast.?
?
## never had any issues, ordering anything from the usa, never.? ?And ZERO issues with customs...items sail right to my front door.? Only the 'select items'? on RF parts site.? ?IMO, just another goofball outfit that I can't throw money at.?
?
##? I just tested both ameritron chokes on my VNA last week.? ?They resonate at? ?12.332 mhz....and also? 16.247 mhz.? ?They will not blow up on any of the 9 x ham bands.? ?They won't blow up on 60m band, and also 11 m.??
They will blow up on those 2 x freqs I stated,? +/-? 750 khz.?
?
## However, I know of at least 12 of em now, that have blown up in the last few years..... typ on 17m.?
##? W8JI sez he used to hand wind em on his machine, in his own shop...for use in all the Ameritron amps.? ?They have to be carefully wound, and using the same magnet wire, and correct placement of gaps, correct turns count on all 3 x windings, and also
correct amount of? that clear...'goop'? they slop on the sides, to keep the winding intact.? Magnet wire comes in 4 x different thickness's of enamel / formvar / nyclad? etc...and for each gauge.? You can also buy magnet wire in 1/2 gauges.? You can also buy
magnet wire in several different temp ratings...and also several different V ratings.? ?Depending on type of insulation used, and thickness,? that alone will change the dielectric constant.?
##? Depending on which of the 4 x? thickness'? used,? etc,? it can easily shift the 2 x series resonance freqs.? ?Get the gaps wrong, and they will shift again.? Slop too much/too little clear goop on the sides of the windings, and it shifts again.?
## JI sez he left ameritron in 2019. ( KM1H said JI got fired, but u know carl). After JI left, ameritron started? winding their own chokes....and it's a disaster.? JI said he had a ham ship? him an ameritron amp in for repair, ( made after 2019)? and? immediately
saw that the plate choke is a? screwed up dog's breakfast.? He said he has seen that several times now.? He also said the gap between bottom winding,...and the chassis is way too close? vs his original version.?
?
## watch out.? Alpha copied the ameritron choke, and make their own version, which looks identical.... and works.? ?RF parts used to sell the alpha version, then switched to only the ameritron version, which is still screwed up.? How the hell they got the?
16.247 mhz? up higher towards the 17m band is beyond me.?
?
## W8JI now refuses to work on ANY ameritron amp, tube or ss.? ?He does sell the original version of the plate choke, built and tested to correct specs.? ?He makes the chokes in his shop, same as before 2019.?
?
## These days, I would check any plate choke on the vna, since they are so cheap (vna).?
|
Re: Ameritron Plate Chokes
On Sat, Feb 17, 2024 at 11:39 PM, Dave w6de wrote:
What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer available for export."
When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions.
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
##? No they don't.? I just recently bought 2 x of the ameritron chokes from? RF parts. ( 2-3 yrs ago).? ?ONLY on some selected items, ( and that choke is NOT one of em, as of 5 mins ago) will they refuse to ship outside the USA.? I had also ordered a pair of 0-4.4 uh roller coils. RF parts would not export em.? I couldn't even get em shipped to a friend in the usa.? ?The only work around was to have a friend in the usa pay for em, and have em shipped to his usa address..... then re-send em to my address via USPS. ..( that advice came from the girl in the office, not the owner, bonny)
?
## merrit Arnold's wife and son now run RF parts.? One of the girls who works there tells me arnolds wife is a ...'real piece of work'.? ?I know other folks who wanted to buy 4x10 tubes..and that was another item they would not ship overseas.? Bonny has some bug up her rear end, about some items that should not be shipped outside of the usa...siting....'only should be sold in america'.? The small 0-4.4 uh roller coil ( 8 ga wire) was originally made by multronics.? ?Then Cardwell condenser co? bought out multronics...and the same roller coils in the RF parts site were indeed stamped...'Cardwell condenser Corp'.? ?Cardwell sold out to 'Viking'? ?( who owns the custom clothing line).? ?I just ordered 2 of the rollers? directly from Viking, no fuss, shipped fast.?
?
## never had any issues, ordering anything from the usa, never.? ?And ZERO issues with customs...items sail right to my front door.? Only the 'select items'? on RF parts site.? ?IMO, just another goofball outfit that I can't throw money at.?
?
##? I just tested both ameritron chokes on my VNA last week.? ?They resonate at? ?12.332 mhz....and also? 16.247 mhz.? ?They will not blow up on any of the 9 x ham bands.? ?They won't blow up on 60m band, and also 11 m.??
They will blow up on those 2 x freqs I stated,? +/-? 750 khz.?
?
## However, I know of at least 12 of em now, that have blown up in the last few years..... typ on 17m.?
##? W8JI sez he used to hand wind em on his machine, in his own shop...for use in all the Ameritron amps.? ?They have to be carefully wound, and using the same magnet wire, and correct placement of gaps, correct turns count on all 3 x windings, and also correct amount of? that clear...'goop'? they slop on the sides, to keep the winding intact.? Magnet wire comes in 4 x different thickness's of enamel / formvar / nyclad? etc...and for each gauge.? You can also buy magnet wire in 1/2 gauges.? You can also buy magnet wire in several different temp ratings...and also several different V ratings.? ?Depending on type of insulation used, and thickness,? that alone will change the dielectric constant.?
##? Depending on which of the 4 x? thickness'? used,? etc,? it can easily shift the 2 x series resonance freqs.? ?Get the gaps wrong, and they will shift again.? Slop too much/too little clear goop on the sides of the windings, and it shifts again.?
## JI sez he left ameritron in 2019. ( KM1H said JI got fired, but u know carl). After JI left, ameritron started? winding their own chokes....and it's a disaster.? JI said he had a ham ship? him an ameritron amp in for repair, ( made after 2019)? and? immediately saw that the plate choke is a? screwed up dog's breakfast.? He said he has seen that several times now.? He also said the gap between bottom winding,...and the chassis is way too close? vs his original version.?
?
## watch out.? Alpha copied the ameritron choke, and make their own version, which looks identical.... and works.? ?RF parts used to sell the alpha version, then switched to only the ameritron version, which is still screwed up.? How the hell they got the? 16.247 mhz? up higher towards the 17m band is beyond me.?
?
## W8JI now refuses to work on ANY ameritron amp, tube or ss.? ?He does sell the original version of the plate choke, built and tested to correct specs.? ?He makes the chokes in his shop, same as before 2019.?
?
## These days, I would check any plate choke on the vna, since they are so cheap (vna).?
|
Re: Ameritron Plate Chokes
Almost every plate choke I see in an ameritron that comes in for repair is not wound properly. I always ask if they had used on 17 meters when I see a fried one , answer is always yes.
I tell everyone to stay of 17 , some listen and some don’t. Ones that don’t listen say they don’t see anything online about issues on 17 meters.
The plate choke issue with 17 used to be posted in numerous places, but now seems to have vanished.
toggle quoted message
Show quoted text
On 2024-02-17 18:22, Alek Petkovic via groups.io wrote: Thanks Robert. There are numerous reports that a batch of the chokes
were burning up on 17m.
Anyway, problem solved, I have emailed W8JI with a view of purchasing
a few of his.
73, Alek VK6APK
On 18/02/2024 9:02 am, Robert W5AJ wrote:
Interesting
I've installed the RFC3 in AL82, RFParts 3-500 with 1600w out into
Navy surplus dummy load. Tested ALL bands including warc. Never
noticed an issue. Solid.
Same with Alpha 89 with RFC3 replacement. Worked great, sold the
Alpha.
I plan on using RFC3 in next HF homebrew.
Robert W5AJ
On Sat, Feb 17, 2024, 3:39 PM Dave w6de <w6de@...> wrote:
What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer
available for export."
When I worked for a US Defense Contractor, I found that Great
Britain, Australia, and New Zealand were exempt from these
restrictions.
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron
High Power Tube Amplifiers are not specified to run on the 10 MHz
(30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected] <[email protected]> On
Behalf Of Alek Petkovic via groups.io [1]
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues with their
spare parts plate chokes?
I would be interested in purchasing a couple if they are not going
to burn up.
73, Alek VK6APK. Links:
------
[1]
[2] /g/ham-amplifiers/message/40230
[3] /mt/104406328/8135091
[4] /g/ham-amplifiers/post
[5] /g/ham-amplifiers/editsub/8135091
[6] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
|
Re: Ameritron Plate Chokes
Dunno mate. we're pretty much accustomed to paying double for
everything in this part of the world, so we don't worry too much
about it.
Guess I'll hear from Tom when he fronts for work this week.
Cheers, Alek.
On 18/02/2024 1:11 pm, Bob wrote:
toggle quoted message
Show quoted text
Alek, How much will it be for them to be shipped
to you?
Bob W4JFA?
Thanks Robert. There are numerous reports that a batch of
the chokes were burning up on 17m.
Anyway, problem solved, I have emailed W8JI with a view
of purchasing a few of his.
73, Alek VK6APK
On 18/02/2024 9:02 am, Robert W5AJ wrote:
Interesting
I've installed the RFC3 in AL82, RFParts
3-500 with 1600w out into Navy surplus dummy load.?
Tested ALL bands including warc.? Never noticed an
issue.? ?Solid.
Same with Alpha 89 with RFC3
replacement.? Worked great, sold the Alpha.
I plan on using RFC3 in next HF
homebrew.
Robert W5AJ?
On Sat, Feb 17, 2024,
3:39 PM Dave w6de < w6de@...>
wrote:
What
are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several
amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No
longer available for export."
When I worked for a US Defense Contractor, I found
that Great Britain, Australia, and New Zealand were
exempt from these restrictions.?
It may be worth an inquiry to see if RF-Parts will
recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and
the Ameritron High Power Tube Amplifiers are not
specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected]
<[email protected]>
On Behalf Of Alek Petkovic via
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues
with their spare parts plate chokes?
I would be interested in purchasing a couple if they
are not going to burn up.
73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Alek, How much will it be for them to be shipped to you? Bob W4JFA?
Thanks Robert. There are numerous reports that a batch of the
chokes were burning up on 17m.
Anyway, problem solved, I have emailed W8JI with a view of
purchasing a few of his.
73, Alek VK6APK
On 18/02/2024 9:02 am, Robert W5AJ
wrote:
Interesting
I've installed the RFC3 in AL82, RFParts 3-500
with 1600w out into Navy surplus dummy load.? Tested ALL bands
including warc.? Never noticed an issue.? ?Solid.
Same with Alpha 89 with RFC3 replacement.?
Worked great, sold the Alpha.
I plan on using RFC3 in next HF homebrew.
Robert W5AJ?
On Sat, Feb 17, 2024, 3:39 PM
Dave w6de < w6de@...>
wrote:
What
are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier
projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer
available for export."
When I worked for a US Defense Contractor, I found that Great
Britain, Australia, and New Zealand were exempt from these
restrictions.?
It may be worth an inquiry to see if RF-Parts will recognize
this.
Note: the RFC3 plate choke resonates at 10 MHz, and the
Ameritron High Power Tube Amplifiers are not specified to run
on the 10 MHz (30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected]
<[email protected]>
On Behalf Of Alek Petkovic via
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues with
their spare parts plate chokes?
I would be interested in purchasing a couple if they are not
going to burn up.
73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Merrit Arnold’s wife took over and lots changed. I send my customers to penta now have for months. If ever a tube issue replacement is quick.
Nothing against rf parts , my customers get the whole sale price on tubes and east warranty replacement . Win win for my customers.
I what’s best for my customers
toggle quoted message
Show quoted text
On 2024-02-17 17:41, Dave w6de wrote: It is probably because of the paperwork blizzard to send something when customs are involved. It appears to be different for each country. I personally have only sent things to Canada and Australia. Canada was easy via the postal service. But it was a mountain of paperwork to send a collector car to Australia (via ship). And, then just to send a spare set of keys and car history paperwork via the post/mail for the car, it was amazing how much paperwork was required--besides the amazing cost for just a large envelope.
73,
Dave, w6de
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of John Sparkes via groups.io
Sent: 17 February, 2024 23:59
To: [email protected]
Subject: Re: [ham-amplifiers] Ameritron Plate Chokes
Is it because you just can't see us from up there...?
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Mike Santas
Sent: Sunday, February 18, 2024 7:19 AM
To: [email protected]
Subject: Re: [ham-amplifiers] Ameritron Plate Chokes
Dave,
I don't think it's an ITAR issue......
73
Mike N2LYM
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Dave w6de
Sent: Saturday, February 17, 2024 5:40 PM
To: [email protected]
Subject: Re: [ham-amplifiers] Ameritron Plate Chokes
What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer available for export."
When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions.
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Alek Petkovic via groups.io
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes?
I would be interested in purchasing a couple if they are not going to burn up.
73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Thanks Robert. There are numerous reports that a batch of the
chokes were burning up on 17m.
Anyway, problem solved, I have emailed W8JI with a view of
purchasing a few of his.
73, Alek VK6APK
On 18/02/2024 9:02 am, Robert W5AJ
wrote:
toggle quoted message
Show quoted text
Interesting
I've installed the RFC3 in AL82, RFParts 3-500
with 1600w out into Navy surplus dummy load.? Tested ALL bands
including warc.? Never noticed an issue.? ?Solid.
Same with Alpha 89 with RFC3 replacement.?
Worked great, sold the Alpha.
I plan on using RFC3 in next HF homebrew.
Robert W5AJ?
On Sat, Feb 17, 2024, 3:39 PM
Dave w6de < w6de@...>
wrote:
What
are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier
projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer
available for export."
When I worked for a US Defense Contractor, I found that Great
Britain, Australia, and New Zealand were exempt from these
restrictions.?
It may be worth an inquiry to see if RF-Parts will recognize
this.
Note: the RFC3 plate choke resonates at 10 MHz, and the
Ameritron High Power Tube Amplifiers are not specified to run
on the 10 MHz (30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected]
<[email protected]>
On Behalf Of Alek Petkovic via
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues with
their spare parts plate chokes?
I would be interested in purchasing a couple if they are not
going to burn up.
73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Interesting
I've installed the RFC3 in AL82, RFParts 3-500 with 1600w out into Navy surplus dummy load.? Tested ALL bands including warc.? Never noticed an issue.? ?Solid.
Same with Alpha 89 with RFC3 replacement.? Worked great, sold the Alpha.
I plan on using RFC3 in next HF homebrew.
Robert W5AJ?
On Sat, Feb 17, 2024, 3:39 PM Dave w6de < w6de@...> wrote: What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer available for export."
When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions.?
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Alek Petkovic via
Sent: 17 February, 2024 02:31
To: [email protected]
Subject: [ham-amplifiers] Ameritron Plate Chokes
Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes?
I would be interested in purchasing a couple if they are not going to burn up.
73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
It is probably because of the paperwork blizzard to send something when customs are involved. It appears to be different for each country. I personally have only sent things to Canada and Australia. Canada was easy via the postal service. But it was a mountain of paperwork to send a collector car to Australia (via ship). And, then just to send a spare set of keys and car history paperwork via the post/mail for the car, it was amazing how much paperwork was required--besides the amazing cost for just a large envelope.
73,
Dave, w6de
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of John Sparkes via groups.io Sent: 17 February, 2024 23:59 To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes Is it because you just can't see us from up there...? -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Mike Santas Sent: Sunday, February 18, 2024 7:19 AM To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes Dave, I don't think it's an ITAR issue...... 73 Mike N2LYM -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Dave w6de Sent: Saturday, February 17, 2024 5:40 PM To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes What are the issues with Ameritron Plate Chokes? I have used an RF Parts look alike for several amplifier projects. More chokes here Unfortunately, RF-Parts now lists these parts as "No longer available for export." When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions. It may be worth an inquiry to see if RF-Parts will recognize this. Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band. 73, Dave, w6de -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alek Petkovic via groups.io Sent: 17 February, 2024 02:31 To: [email protected]Subject: [ham-amplifiers] Ameritron Plate Chokes Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes? I would be interested in purchasing a couple if they are not going to burn up. 73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Is it because you just can't see us from up there...?
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Mike Santas Sent: Sunday, February 18, 2024 7:19 AM To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes Dave, I don't think it's an ITAR issue...... 73 Mike N2LYM -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Dave w6de Sent: Saturday, February 17, 2024 5:40 PM To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes What are the issues with Ameritron Plate Chokes? I have used an RF Parts look alike for several amplifier projects. More chokes here Unfortunately, RF-Parts now lists these parts as "No longer available for export." When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions. It may be worth an inquiry to see if RF-Parts will recognize this. Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band. 73, Dave, w6de -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alek Petkovic via groups.io Sent: 17 February, 2024 02:31 To: [email protected]Subject: [ham-amplifiers] Ameritron Plate Chokes Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes? I would be interested in purchasing a couple if they are not going to burn up. 73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
Dave,
I don't think it's an ITAR issue......
73
Mike N2LYM
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Dave w6de Sent: Saturday, February 17, 2024 5:40 PM To: [email protected]Subject: Re: [ham-amplifiers] Ameritron Plate Chokes What are the issues with Ameritron Plate Chokes? I have used an RF Parts look alike for several amplifier projects. More chokes here Unfortunately, RF-Parts now lists these parts as "No longer available for export." When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions. It may be worth an inquiry to see if RF-Parts will recognize this. Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band. 73, Dave, w6de -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alek Petkovic via groups.io Sent: 17 February, 2024 02:31 To: [email protected]Subject: [ham-amplifiers] Ameritron Plate Chokes Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes? I would be interested in purchasing a couple if they are not going to burn up. 73, Alek VK6APK.
|
Re: Ameritron Plate Chokes
What are the issues with Ameritron Plate Chokes?
I have used an RF Parts look alike for several amplifier projects.
More chokes here
Unfortunately, RF-Parts now lists these parts as "No longer available for export."
When I worked for a US Defense Contractor, I found that Great Britain, Australia, and New Zealand were exempt from these restrictions.
It may be worth an inquiry to see if RF-Parts will recognize this.
Note: the RFC3 plate choke resonates at 10 MHz, and the Ameritron High Power Tube Amplifiers are not specified to run on the 10 MHz (30 Meters) band.
73,
Dave, w6de
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alek Petkovic via groups.io Sent: 17 February, 2024 02:31 To: [email protected]Subject: [ham-amplifiers] Ameritron Plate Chokes Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes? I would be interested in purchasing a couple if they are not going to burn up. 73, Alek VK6APK.
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Does anyone know if Ameritron have resolved the issues with their spare parts plate chokes?
I would be interested in purchasing a couple if they are not going to burn up.
73, Alek VK6APK.
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Re: Loaded Plate chokes...again
And they are using this 88uh loaded plate choke in the normal place... at the anode ???
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Re: Loaded Plate chokes...again
This one:
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73
Peter
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-----Original-Nachricht-----
Betreff: Re: [ham-amplifiers] Loaded Plate chokes...again
Datum: 2024-02-16T16:34:06+0100
Von: "Jim VE7RF" <jim.thom@...>
An: "[email protected]" <[email protected]>
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Where is the? 88 uh...down at the bottom ???
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Re: Loaded Plate chokes...again
Where is the? 88 uh...down at the bottom ???
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Re: Loaded Plate chokes...again
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The version on the posted photo has 88?H.
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It is also used in the 20kW R&S VK20 amp with RS1082CL? at 8kV 5A ,1.5-30MHz, 24/7.
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73
Peter
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-----Original-Nachricht-----
Betreff: Re: [ham-amplifiers] Loaded Plate chokes...again
Datum: 2024-02-16T12:27:05+0100
Von: "Jim VE7RF" <jim.thom@...>
An: "[email protected]" <[email protected]>
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On Thu, Feb 15, 2024 at 08:33 PM, Peter Voelpel wrote:
The Rohde&Schwarz chokes are with solid rod.
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73
Peter
##? How much B+ ?? ?How much plate current ?? What freqs ?? ?How much uh is their loaded plate chokes??
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Re: Loaded Plate chokes...again
On Thu, Feb 15, 2024 at 02:40 AM, Brandon DX wrote:
<Total inductance 125uH using #20 AWG high temp Formvar?
##? 125 uh would work....just, on 80m.? ( 1,5 amps of RF flowing through the choke on 75m).? With the bigger 20 ga magnet wire used, it would work.?
125 uh would result in 2.97 amps of RF flowing through the choke on 1.8 mhz.? That's in addition to the 2.5 amps of DC plate current.??
## Reids method involves using a vac relay to short out the bigger choke. Henry radio used a modified HV solenoid to short out the big choke in their 8K ultra. With relay contacts open, and both chokes in series, the open contacts have to be able to stand off the peak RF voltage plus the B+.?
## the other method commonly used, is 2 x chokes, big and small in series.? Bypass cap at cold end of big choke. Bypass cap coming off the junction point.? Any simple, spst-NO relay used to? both RF and also DC ground the cold end of the? junction cap.? This effectively removes the big choke from the circuit.? ? ?Cold end of this junction cap? has 3 megohms between cold end of junction cap and chassis.? This ensures the junction cap is truly in DC block mode.? ?Without the 3 megohms of resistance in there, the cold end of the cap will have full B+ on it.? ( we found that out the hard way on the previous 3x6, 160-15m amp, built back in 2007).? ?Reason is, the doorknob? bypass cap has internal leakage? resistance, and even if sky high internal resistance, the cold end still assumes full B+).? ? With full B+ on the cold end of the cap, the B+ would arc the open contact on the relay.? The only? fix is to install the 3 x megohms.? ( typ 3 x 1 meg, 1/2 watt CC resistors used in the older alpha amps, like the 87A, which also used the same 2 x choke + junction cap + relay scheme).?
With relay closed, the cold end of the junction cap is now? BOTH? dc grnded...AND also RF grounded.? Big choke is then? electrically out of the circuit.? With relay open, both chokes in the circuit.?
This scheme sorta works good.? Problem is, both chokes in series can only be used on 160m.? ?When both chokes used in series on 80+40m, the peak RF Voltage? is just wicked, and the vac relay would arc.? Charlie Asamoto used this exact same config ( using a plane jane cheap spst-NO mech relay)? ?when he had his Creative electronics amplifier company. ( Now called? ASI, or amp systems inc).? ?Back then, Charlie used a? 45 uh choke in series with a 135 uh choke. Both chokes used on 160m only. Smaller 45 uh choke used on 80-10m.? ?Same deal, both choke can only be used on 160m.?
On that 3x6 amp, built in 2007, we used 135 uh + 45 uh.? ?We did not know about the 3 megohms that was required. ( we found out abt that in the alpha schematic).? ?Since the amp was only 160-15m, we tried other configs, like increasing the big choke to 180 uh.? ?Also replaced the 45 uh smaller choke ( wound with 18 ga wire)? ?with a 70 uh choke ( it's only a 160-15m amp,? wound with 22 ga magnet wire).? ?The 70 uh choke works better on 80m, but still the same issue, both chokes can only be used on 160m.?
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Peter proposed ( on the VNA.io group)? putting the block cap down at the 50 ohm end of the tank circuit, then only a smaller 50-70uh choke required....similar to the safety choke across the load cap in a conventional? amp.? Problem with that is...the B+ is now on the tune and load caps...and also the tank coils, and the bandswitch.? IE: block cap wired in series with the output of the amp.? Per HEC ( high energy corp) et all, the max peak V you can out across any of their caps is equal to the peak RF voltage across the cap PLUS any ...'DC bias'.? ?What HEC calls 'DC bias, hams call it? B+.? There are no caps suitable in either the HT-57 nor the bigger HT-59 size, that will work for this application.? Nor any of the 100mm diam draloric / HEC 'Frisbee'? style caps. Only the 150mm diam frisbee caps, or the tubular caps would work.?
12.8 kw output = 16 amps of RF on the 50 ohm output.? Calculate the XC of the block cap on 160m, then multiply by? 16 amps =? RMS? R voltage across the cap.? ?Then add 41.4% to get the peak RF voltage value. Then add the B+ on top of that.? That's what you will have on 160m, 160m being the worse case, since the Xc for a given block cap value, will have the highest Xc on the lowest freq used.? ?There are no? HT-57 / HT-59 caps, even with caps in parallel, that will? handle the sky high voltage? across the cap(s) and? RF current through the caps.?
The concept wouldn't work anyway.? ?The vac tune cap would have to be a minimum of 25 kv rated.? The vac load cap would also have to be a much larger V rated unit, like 10+ kv minimum. The bandswitch would have to be 20 kv minimum (type 90? switch).? ?We only have access to 5kv rated vac load caps (3000 pf + 4000 pf)...and I have hi-pot tested the 4000 pf @ 5 kv rated Jennings load caps...and they are only good up to 5200 vdc.??
The ARRL handbook explains abt using a block cap at the 50 ohms end, in the output to the tr relays,? (so a simple plate choke can be used).? ?To get around the full B+ across the load cap, they depict method #2.? ?Method #2 places the block cap at the end of the tank coil, just before the load cap to coil junction point.? The idea is then there is NO B+ on the load cap at all.? ?But you still have B+? on the tune cap, and the tank coil(s), and the bandswitch.? ?With the block cap at the end of the tank coil, the block cap now has the full RF tank current flowing through it.? That's just dc plate current x loaded tank Q.? IE: 2.5 amps dc plate current x 10? = 25 amps rms of RF current now flowing through the poor block cap.? ?Well good luck with that method.? Now you have the full 25 amps? flowing through the block cap on ALL bands.? On 160m, the peak V across the block cap is wicked..... ( XC on 160m is? 16 x greater vs 10m).? RMS V is now 25 amps x XC on 1.8 mhz....? then add in the B+ on top of all that.?
Both? above methods are fubar imo.?
At least with the loaded choke scheme, only ONE choke is required.? ?No vac relay required.? And plenty of uh, so the choke has minimal RF current flowing through it on 160m.?
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Re: Loaded Plate chokes...again
On Thu, Feb 15, 2024 at 08:33 PM, Peter Voelpel wrote:
The Rohde&Schwarz chokes are with solid rod.
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73
Peter
##? How much B+ ?? ?How much plate current ?? What freqs ?? ?How much uh is their loaded plate chokes??
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Bob
Robert, W5AJ