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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
If a? big? arc occurs? when? contacts? closing,? something? is? not? designed? correctly.? ?That? is? no place? for? puny? 10-20 A? rated? contacts,? or? using real? short? delays.? Just? increasing? the delay? a? bunch? would? go a long? way? to minimizing the? arc.?
? Jim? VE7RF |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Cliff Fox (KU4GW)
Hi Don,
? ? ? ? ? ? That info is in the user manual page 13 for the schematic and page 14 for the parts list available fore free from the Ameritron website at??and also available free of charge at? Very 73, Cliff - KU4GW |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Here? is? how? I? did? my? external step? start.? ?I? used? a? ?8"? x 8"? x 4"? electrical? box....with? knock? outs.
240? vac? line, using 10? gauge? wire, is hardwired? from? 2? pole? breaker? in my? 100A sub panel..to? 8x8x4? box.? 240? power? cable? from L4PS? also? hardwired? to same? 8x8x4? box.? Garden? variety? DPST? 30A? relay,? (P+B,? deltrol,? etc)? is? installed in? 8x8x4 box...and used? to? apply? the? 240? vac. (Drake RF? deck? ON/OFF? switch? left to? ON? position). 2nd? relay,? SPST,? also? 30A,? used to? shunt? the? 25? ohm @ 100? watt? wire? wound.? Wire wound? mounted? on? standoff's.? So? 2 x relays + resistor mounted in? the? 8x8x4? box.? Small? control? cable wired? from? 8x8x4? box? to? desk....? terminating? in a small? mini? box.? Mini? box? has? 2 x? miniature? toggle? switches on it.? ?One? toggle? per? relay? coil. Toggle? #1? applies? 240? vac.? After 3-5 secs,? toggle? #2 is activated,? shunting the? 25? ohm resistor.? Dead simple.? ?Step? starts both the? B+? AND? the? fils....at the? same? time.? ZERO? arcing? when? either? relay is activated.? ?It's? just a? manual? step? start? setup.? 250 Volt? MOV? across SPST? step? start? relay? contacts.? (130 Volt? MOV? across? coils? of both? relay? coils).? If switching? from? 2650 vdc....down? to? 1900? vdc,? no? problem.? ?But? when? switching back? from? 1900? to? 2650? vdc, the? ?toggle? #2? is? 1st? activated....? putting? the? resistor? back inline. Toggle #2? ?then activated,? again? shunting? resistor.? 240? vac /? 25 ohms? = 9.6? amps? =? ?2304 watts...when? T=0.? That only? last a? few? Msecs? as? caps? charge? up.? ?(The? harbach board? uses a 22 ohm,? 25 watt cement? resistor). (I? have? also used a? 0-15? sec? adjustable? timer? to apply the? 120 vac? to the? coil? of the step start contactor....? but? that's? only? on? Big? ?HB? B+? supplies,? and ONLY? the? B+? supply? is? step? started. The? fil? from? the? tube? has it's? own? step? start /variac? combo...? bigger? metal? triodes). Jim? VE7RF?? |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Any Schematics with relay numbers for home builders ?
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Don W4DNR Quoting "Louis Parascondola via Groups.Io" <Gudguyham@...>: The Ameritron outboard step start is the same circuit that is built |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Cliff Fox (KU4GW)
Thanks for all the replies guys, over a dozen and I will post what I end up doing if P.J comes up with the moo-la if any is required. This group is absolutely awesome and a excellent source to get some good advice and I will always use the left-hand rule when working around any voltages exceeding 50 volts. Thanks so much! I think I have all the info I need now to hopefully get P.J., KN4UNA's amplifier in the proper working order.? Very 73 de Cliff "It's not the class of license that the Amateur holds, it's the class of the Amateur who holds the license!"? |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
The Ameritron outboard step start is the same circuit that is built into the Al-1200 amp.?? -----Original Message-----
From: cturnertuning <clark@...> To: ham-amplifiers <[email protected]> Sent: Wed, Jan 29, 2020 11:49 am Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube) Ameritron makes an outboard box that the amp or any amp plugs into that
has step start built in. Not sure whats inside. Maybe MOV?? I like to build my own but this might be an option as you would not have to modify the amp or any other amp you own. Other options would be a resistor/cap across the contacts. I have a chart here somewhere to select the value. It appeared in Electric radio magazine.? I have used this before on boat anchor transmitter relays and the spark was gone.? I recently added MOVs to my Johnson 500. It had 25 AMPS of startup current that banged the hell out of the plate transformer.? Startup is now 2 to 3 amps at the peak and rises up dead silent on key up. C > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of Don Roden > Sent: January 28, 2020 10:18 AM > To: [email protected] > Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube) > > > >> It has a problem with giving a arc when the power switch is first turned on. >> >>? Cliff, KU4GW >> > Cliff, > > Is it a bang or a BANG ?? A tick or a TICK ?? a snap or a SNAP !? ? > > Do you hear it across the room ?? Does your butt lift off the chair ? > > Just trying to gauge the severity. > > Don W4DNR > > > > > > > > -- Please let me quote you for your parts needs! I offer a discount on Protunes with parts order! Clark Turner 480-695-2898 |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Ameritron makes an outboard box that the amp or any amp plugs into that has step start built in. Not sure whats inside. Maybe MOV?? I like to build my own but this might be an option as you would not have to modify the amp or any other amp you own. Other options would be a resistor/cap across the contacts. I have a chart here somewhere to select the value. It appeared in Electric radio magazine.? I have used this before on boat anchor transmitter relays and the spark was gone.? I recently added MOVs to my Johnson 500. It had 25 AMPS of startup current that banged the hell out of the plate transformer.? Startup is now 2 to 3 amps at the peak and rises up dead silent on key up.
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C -----Original Message------- Please let me quote you for your parts needs! I offer a discount on Protunes with parts order! Clark Turner 480-695-2898 |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Yes indeed Jim.? if you have watched the start up of as many "big box" Ameritron amps (all the same except for tube) you would see varying degrees of sparking at the step start relay contacts depending on the AC cycle as the contacts close.? Sometimes the spark is little to none and sometimes moderate to high.? The multi-modification board sold by Harbach for the Darke L4 (b) amps include a step start and it delays about 3 second almost.? Very nice.? This Drake board is "technically" not compatible with the L7 amps, but I examined the Drake L7 schematic and the modification board, and I found it is very simple to adapt that board to the L7 model amp.? I did it on a couple and it works fine.? -----Original Message-----
From: Jim VE7RF <jim.thom@...> To: ham-amplifiers <[email protected]> Sent: Wed, Jan 29, 2020 9:09 am Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube) A? ?HD? MOV? ?across? the? contacts? would? work? better.? ? ?Lou? sez? the? delay? is? not? long? enough.? ? 2-3? seconds? would? be? optimum...and? minimize? any? secondary? surge.?
You? want? the? B+? to? get? as? high? as? possible....? before? shunting? the? step? start? resistor. Jim? ?VE7RF? |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
A? ?HD? MOV? ?across? the? contacts? would? work? better.? ? ?Lou? sez? the? delay? is? not? long? enough.? ? 2-3? seconds? would? be? optimum...and? minimize? any? secondary? surge.?
You? want? the? B+? to? get? as? high? as? possible....? before? shunting? the? step? start? resistor. Jim? ?VE7RF? |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
I think Lou has it worked out but I love your bit about the butt off the chair.
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That's why I love building and working i=on tube amplifiers. Every now and then you get one of those incidents and the adrenalin rush is such a great feeling. 73, Alek. VK6APK On 29/01/2020 12:17 am, Don Roden wrote:
It has a problem with giving a arc when the power switch is first turned on.Cliff, |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Clint, VE3CMQ
You might want to put a 0.1UF to 1UF non-polarised capacitor across the contacts if there isn't one. This is usually done to prevent arcing across AC contacts.
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Clint, VE3CMQ -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Don Roden Sent: January 28, 2020 10:18 AM To: [email protected] Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube) It has a problem with giving a arc when the power switch is first turned on.Cliff, Is it a bang or a BANG ? A tick or a TICK ? a snap or a SNAP ! ? Do you hear it across the room ? Does your butt lift off the chair ? Just trying to gauge the severity. Don W4DNR |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
It has a problem with giving a arc when the power switch is first turned on.?Cliff, Is it a bang or a BANG ? A tick or a TICK ? a snap or a SNAP ! ? Do you hear it across the room ? Does your butt lift off the chair ? Just trying to gauge the severity. Don W4DNR |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
The arc is normal, just about all of them do it to some degree based on how bad the contacts have been pitted.? Eventually the step start relay may need replacing. -----Original Message-----
From: Cliff Fox (KU4GW) <cliffku4gw@...> To: ham-amplifiers <[email protected]> Sent: Mon, Jan 27, 2020 11:50 pm Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube) No, not yet Alek, I'm planning on taking the cover off it tomorrow afternoon. One guy in Idaho told me the step-start relay may be the culprit or it could need the electrolytic caps replaced. If I could see the arc it would be very helpful, but I'm reluctant to turn it on without the cover on it, it may kill me! Maybe I can hear it, P.J. told me what it was doing when he brought it here, but I haven't hooked it up yet. The guy in Idaho told me the step-start relay in on the left side at the back so if I can hear it arc back in that area then maybe P.J. should order a new relay from Ameritron. Hopefuly I'll find a sign of the arc like a burnt or discolored resistor or a leaky capacitor, something I can see.?Thanks for your reply!
Very /73 de Cliff
On Mon, Jan 27, 2020 at 8:56 PM Alek Petkovic <vk6apk@...> wrote:
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
The arc is at the step start contacts just as it makes contact to short out the step start resistor.? The delay is a bit short. -----Original Message-----
From: DupyRail <andymueller@...> To: ham-amplifiers <[email protected]> Sent: Tue, Jan 28, 2020 3:02 am Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Being curious, what exactly is arcing?
Andy? K9ATX On 1/27/2020 6:05 PM, Cliff Fox (KU4GW)
wrote:
I have a Ameritron AL-1200 brought to me by the KN4UNA, P.J., who
received the amp from his uncle's estate (W4WWF Dale Mash SK) and
it has a problem with giving a arc when the power switch is first
turned on. The amp runs fine after that initial arc. Can anyone
offer any advice on what I should check that may be the cause? I
own a AL-80B and I know it has a inrush current step-start circuit
in it to prevent a surge, but know nothing about the AL-1200. Does
it have inrush current protection or a step-start circuit? I had a
issue with my AL-80B a while back arcing from the tube parasitic
resistors to the shaft going to the band switch. I wrapped the
shaft in heat shrink tubing and that solved that problem. What
should I check first in the AL-1200, perhaps a current limiting
resistor? The amp is as clean as a pin and looks like brand new!
Thanks in advance and very 73!?
Cliff, KU4GW -- "Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Web page at: |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
The Step Start relay arc is normal.? They all do it when the start is on an AC cycle peak or close to it. -----Original Message-----
From: DupyRail <andymueller@...> To: ham-amplifiers <[email protected]> Sent: Tue, Jan 28, 2020 3:02 am Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
FWIW, keep one hand in your pocket while doodling with it.
Andy? K9ATX On 1/27/2020 10:49 PM, Cliff Fox
(KU4GW) wrote:
No,
not yet Alek, I'm planning on taking the cover off it
tomorrow afternoon. One guy in Idaho told me the
step-start relay may be the culprit or it could need the
electrolytic caps replaced. If I could see the arc it
would be very helpful, but I'm reluctant to turn it on
without the cover on it, it may kill me! Maybe I can hear
it, P.J. told me what it was doing when he brought it
here, but I haven't hooked it up yet. The guy in Idaho
told me the step-start relay in on the left side at the
back so if I can hear it arc back in that area then maybe
P.J. should order a new relay from Ameritron. Hopefuly
I'll find a sign of the arc like a burnt or discolored
resistor or a leaky capacitor, something I can see.?Thanks
for your reply!
Very
/73 de Cliff
On Mon, Jan 27, 2020 at
8:56 PM Alek Petkovic <vk6apk@...>
wrote:
-- "Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Web page at: |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
开云体育Yep. Take off the cover and get something to hold down the cover
safety switch. Activate the power switch and then plug it into a
live extension cable to apply the power. That way, you are holding
the plug and socket, so you can stand back safely, and observe,
without needing to touch anything on or in the amplifier. Good luck. Alek. On 28/01/2020 1:50 pm, DupyRail wrote:
FWIW, keep one hand in your pocket while doodling with it. |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
开云体育FWIW, keep one hand in your pocket while doodling with it.Andy? K9ATX On 1/27/2020 10:49 PM, Cliff Fox
(KU4GW) wrote:
-- "Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Web page at: |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
开云体育Being curious, what exactly is arcing?Andy? K9ATX On 1/27/2020 6:05 PM, Cliff Fox (KU4GW)
wrote:
I have a Ameritron AL-1200 brought to me by the KN4UNA, P.J., who received the amp from his uncle's estate (W4WWF Dale Mash SK) and it has a problem with giving a arc when the power switch is first turned on. The amp runs fine after that initial arc. Can anyone offer any advice on what I should check that may be the cause? I own a AL-80B and I know it has a inrush current step-start circuit in it to prevent a surge, but know nothing about the AL-1200. Does it have inrush current protection or a step-start circuit? I had a issue with my AL-80B a while back arcing from the tube parasitic resistors to the shaft going to the band switch. I wrapped the shaft in heat shrink tubing and that solved that problem. What should I check first in the AL-1200, perhaps a current limiting resistor? The amp is as clean as a pin and looks like brand new! Thanks in advance and very 73!? -- "Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Web page at: |
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Cliff Fox (KU4GW)
No, not yet Alek, I'm planning on taking the cover off it tomorrow afternoon. One guy in Idaho told me the step-start relay may be the culprit or it could need the electrolytic caps replaced. If I could see the arc it would be very helpful, but I'm reluctant to turn it on without the cover on it, it may kill me! Maybe I can hear it, P.J. told me what it was doing when he brought it here, but I haven't hooked it up yet. The guy in Idaho told me the step-start relay in on the left side at the back so if I can hear it arc back in that area then maybe P.J. should order a new relay from Ameritron. Hopefuly I'll find a sign of the arc like a burnt or discolored resistor or a leaky capacitor, something I can see.?Thanks for your reply! Very /73 de Cliff On Mon, Jan 27, 2020 at 8:56 PM Alek Petkovic <vk6apk@...> wrote:
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Re: Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
开云体育Have you determined where the arc might be? Bandswitch, RF deck, power supply, power switch, transformer, filter caps, etc? 73, Alek. VK6APK On 28/01/2020 8:05 am, Cliff Fox
(KU4GW) wrote:
I have a Ameritron AL-1200 brought to me by the KN4UNA, P.J., who received the amp from his uncle's estate (W4WWF Dale Mash SK) and it has a problem with giving a arc when the power switch is first turned on. The amp runs fine after that initial arc. Can anyone offer any advice on what I should check that may be the cause? I own a AL-80B and I know it has a inrush current step-start circuit in it to prevent a surge, but know nothing about the AL-1200. Does it have inrush current protection or a step-start circuit? I had a issue with my AL-80B a while back arcing from the tube parasitic resistors to the shaft going to the band switch. I wrapped the shaft in heat shrink tubing and that solved that problem. What should I check first in the AL-1200, perhaps a current limiting resistor? The amp is as clean as a pin and looks like brand new! Thanks in advance and very 73!? |
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