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Reply from ECONCO
Hello Jim, If the Svetlana tubes have good grids then we can repair them. If the grids are bad then we don¡¯t rebuild them. We don¡¯t buy Svetlana duds so we don¡¯t normally have stock on Svetlana tubes. As far as the Chinese duds go we can rebuild them but we don¡¯t replace seals, ceramics or anodes on them no major work. So if they are new duds then we usually can repair them at least once. If you have any other questions please let me know. ? Thank you Matt Lindsey Econco/Technical Customer Service 1318 Commerce Ave. Woodland CA? 95776 800-532-6626 Ext 101
? ##? Typ, if the? tube? has lost? emission,? they? re-thoriate the? directly? heated? cathode...? with acetylene gas.? ?With? Eimac? tubes,? they can also? replace grids,? anode, ceramic... both on? triodes + tetrodes.? ? See? their reply? above, re:? svetlana + chinese tubes.? Jim? ?VE7RF? ? |
Re: Series DC Blocking cap.
I got mine from Amp Supply and later from Bill Edwards, K4BWC (SK) who was their Service Mgr and ran Omega Electronics. After he died I bought several items from his estate.
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I believe Ameritron uses them also. Check their big amps and auto tuner. ----- Original Message -----
From: jim.thom@... [ham_amplifiers] To: ham_amplifiers@... Sent: Saturday, June 29, 2019 4:39 PM Subject: Re: [ham_amplifiers] Re: Series DC Blocking cap. <Teflon dielectric discs have been available for decades at least to 1000pf <and maybe higher. <Ive used them for decades when modifying amp pi networks to work into high <VSWR's on 160-80. <Carl ## where do you buy these teflon caps ? I'm looking everywhere, with not much success. Jim VE7RF --- This email has been checked for viruses by AVG. |
Re: Series DC Blocking cap.
<Teflon dielectric discs have been available for decades at least to 1000pf? <and maybe higher. <Ive used them for decades when modifying amp pi networks to work into high? <VSWR's on 160-80. <Carl ##? where? do you buy these teflon caps ?? ? I'm looking everywhere, with not much success.? Jim? VE7RF |
Re: Series DC Blocking cap.
BUT there are no .02 NPO caps and there is no reason to have so much C in the RF path.
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Anything over 2000pf is overkill. ----- Original Message -----
From: 'Leigh Turner' invertech@... [ham_amplifiers] To: ham_amplifiers@... Sent: Friday, June 28, 2019 12:39 AM Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. Indeed they do. The current handling / rating is usually defined by the capacitor's Equivalent Series Resistance / ESR and its dielectric losses Dissipation Factor / loss tangent which is highly dielectric material dependent. High K dielectrics tend to be lossy while NPO class dielectric leaded ceramic disk capacitors generally perform much better where significant RF current is flowing. Leigh VK5KLT From: ham_amplifiers@... [mailto:ham_amplifiers@...] Sent: Friday, 28 June 2019 1:53 PM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Re: Series DC Blocking cap. Capacitors have current ratings too. Voltage is one parameter and the current rating is another. Lee, w0vt On 6/27/2019 11:14 PM, jim.thom@... [ham_amplifiers] wrote: <Slightly off topic, <I am using an old Heathkit antenna switch that has the control voltages riding on the coax. The <series DC blocking capacitor in the outside box has a piece chipped out of it. Maybe lighting, <maybe power did it. It's an .02 uf 1.6 KV disk. <I bought a .02uf 3 KV disk Vishay and installed it. If I run a 1500 watt carrier through it for about <15 seconds, it gets warmer than lukewarm. Warmest on 10 meters as I would expect. <Would one expect the cap to be warm to hot after that amount of time? Any suggestions on what I should put in there? Curiously, the inside control box uses two of the .02 caps in parallel, not one as the outside box does. <Jim - KR9U ## 1500 watts = 5.5 amps into 50 ohms. That's a helluva lot of current. The problem with disc ceramic caps is.... they never post any RF current ratings on them. Ideally, they should post a CCS RF current vs freq chart. Actual current ratings are all over the map...and must be determined by testing. ## Big difference between a .01 uf @ 1 kv rated cap... vs a ..01uf @ 2 kv rated cap... the 2 kv versions are typ bigger diam, like 25mm OD... vs the smaller diam 1 kv units. The 2 kv versions, being bigger diam, handle more current..which testing confirms. Once you get to the 3+ kv rated units, they don't appear to handle any additional current, just a greater V rating. ## I bought 2 x doz .01uf @ 1.3 kv disc ceramics from RF parts last year. Huge things at 25mm OD, and really thick. These things handle loads of current, best yet so far. ## For your heath switch box application, parallel a 2nd cap in the remote switch box...then re-test. Parallel a 3rd cap if required. You should have zero heat..on any freq. Dunno if the heath box is good up to 6m or not. Jim VE7RF --- This email has been checked for viruses by AVG. |
Re: Series DC Blocking cap.
Teflon dielectric discs have been available for decades at least to 1000pf and maybe higher.
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Ive used them for decades when modifying amp pi networks to work into high VSWR's on 160-80. Carl ----- Original Message -----
From: 'Leigh Turner' invertech@... [ham_amplifiers] To: ham_amplifiers@... Sent: Friday, June 28, 2019 8:39 PM Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. Indeed Jim; that limitation of high Q COG / NPO material ceramic to low C values is correct....generally limited to a few hundred pF to 1 nF or so. Bottom line is lossy X7R, Z5U, Y5V, etc ceramic disk caps are not meant to be used in high RF current applications....better to use multilayer RF chip HV caps like ATC, Murata, AVX, etc. if low ESR and DF dielectric loss is desired. Clusters of Hi-K ceramic HV disks are quite OK for bypassing the tank plate RFC choke, etc. Similar issue with tank circuit padder LOAD capacitors....choose the wrong dielectric doorknob cap and they get hot and drift in value and degrade over time. Leigh VK5KLT ________________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] Sent: Saturday, 29 June 2019 12:19 AM To: ham_amplifiers@... Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. Posted by: jim.thom@... LEIGH, When was the last time you ever saw a NPO .01uf DISC CERAMIC ???? They don't exist, never did. They are typ Z5u, z5t etc. I have never seen RF current ratings for disc ceramics, rf current ratings vs freq, nor ESR at a freq. Jim VE7RF From: ham_amplifiers@... [mailto:ham_amplifiers@...] Sent: Friday, 28 June 2019 2:09 PM To: ham_amplifiers@... Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. Indeed they do. The current handling / rating is usually defined by the capacitor's Equivalent Series Resistance / ESR and its dielectric losses Dissipation Factor / loss tangent which is highly dielectric material dependent. High K dielectrics tend to be lossy while NPO class dielectric leaded ceramic disk capacitors generally perform much better where significant RF current is flowing. Leigh VK5KLT --- This email has been checked for viruses by AVG. |
Re: Series DC Blocking cap.
Indeed Jim; that limitation of high Q COG / NPO material ceramic to low C
values is correct....generally limited to a few hundred pF to 1 nF or so. Bottom line is lossy X7R, Z5U, Y5V, etc ceramic disk caps are not meant to be used in high RF current applications....better to use multilayer RF chip HV caps like ATC, Murata, AVX, etc. if low ESR and DF dielectric loss is desired. Clusters of Hi-K ceramic HV disks are quite OK for bypassing the tank plate RFC choke, etc. Similar issue with tank circuit padder LOAD capacitors....choose the wrong dielectric doorknob cap and they get hot and drift in value and degrade over time. Leigh VK5KLT ________________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] Sent: Saturday, 29 June 2019 12:19 AM To: ham_amplifiers@... Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. ?Posted by: jim.thom@... LEIGH, When was the last time you ever saw a NPO?.01uf? DISC CERAMIC? ????? ? They don't exist, never did.? ?They are typ Z5u, z5t etc.? I have never seen RF current ratings for disc ceramics,?rf current ratings vs? freq,? nor? ESR at a freq.?? Jim? ?VE7RF From: ham_amplifiers@... [mailto:ham_amplifiers@...] Sent: Friday, 28 June 2019 2:09 PM To: ham_amplifiers@... Subject: RE: [ham_amplifiers] Re: Series DC Blocking cap. Indeed they do. The current handling / rating is usually defined by the capacitor¡¯s Equivalent Series Resistance / ESR and its dielectric losses Dissipation Factor / loss tangent which is highly dielectric material dependent. High K dielectrics tend to be lossy while NPO class dielectric leaded ceramic disk capacitors generally perform much better where significant RF current is flowing. Leigh VK5KLT |
Re: Series DC Blocking cap.
¿ªÔÆÌåÓýPublished current ratings and actual cap ratings may or may not co exist.? But the fact remains an application may require a cap with an appropriate capacitor current capability.? I have a Johnson Valiant as an example.? It had two banks of series silver mica capacitors in parallel.? (Factory)? One day it gave up the ghost and I replaced it with just two in series.? Big mistake.? It blew up.? That was the day I learned about capacitor current ratings and why Johnson had 4 of them in there instead of one. Lee, w0vt? On 6/28/2019 9:49 AM,
jim.thom@... [ham_amplifiers] wrote:
? |
Re: Series DC Blocking cap.
¿ªÔÆÌåÓýIndeed they do. The current handling / rating is usually defined by the capacitor¡¯s Equivalent Series Resistance / ESR and its dielectric losses Dissipation Factor / loss tangent which is highly dielectric material dependent. ? High K dielectrics tend to be lossy while NPO class dielectric leaded ceramic disk capacitors generally perform much better where significant RF current is flowing. ? Leigh VK5KLT ? From:
ham_amplifiers@...
[mailto:ham_amplifiers@...]
? Capacitors have current ratings too. Voltage is one parameter and the current rating is another. Lee, w0vt On 6/27/2019 11:14 PM, jim.thom@...
[ham_amplifiers] wrote:
|
Re: Series DC Blocking cap.
¿ªÔÆÌåÓýCapacitors have current ratings too. Voltage is one parameter and the current rating is another. Lee, w0vt On 6/27/2019 11:14 PM,
jim.thom@... [ham_amplifiers] wrote:
? |
Re: Series DC Blocking cap.
<Slightly off topic,? <I am using an old Heathkit antenna switch that has the control voltages riding on the coax.??The <series DC blocking capacitor in the outside box has a piece chipped out of it.??Maybe lighting, <maybe power did it.??It¡¯s an .02 uf??1.6 KV disk. ? <I bought a .02uf??3 KV disk Vishay and installed it.??If I run a 1500 watt carrier through it for about <15 seconds, it gets warmer than lukewarm.?? Warmest on 10 meters as I would expect. ? <Would one expect the cap to be warm to hot after that amount of time????Any suggestions on <what I should put in there????Curiously, the inside control box uses two of the .02 caps in parallel, <not one as the? outside box does. ? <Jim ¨C KR9U ##? 1500? watts? =? 5.5 amps into? 50 ohms.? That's a helluva lot of current.? The problem? with? disc ceramic caps is.... they never post any RF? current ratings on them.? ?Ideally, they should post a? ?CCS? RF? current? vs? freq chart.? ?Actual? current ratings are all over the map...and must be? determined by testing.? ##? Big difference between? a .01 uf? @ 1 kv rated cap... vs a .01uf? @ 2 kv rated cap... the 2 kv? versions are typ bigger diam, like 25mm? OD... vs the smaller diam? 1 kv units.? ?The? 2 kv versions, being bigger diam, handle more current..which testing confirms.? ?Once you get to the? 3+? kv rated units, they don't appear to handle any additional current,? just a greater V? rating.? ##? I bought 2 x doz? .01uf @ 1.3 kv? disc ceramics? from RF parts? last year.? Huge things at? 25mm? OD, and really thick.? ?These things handle loads of current, best yet so far.? ## For? your heath switch box application,? parallel a 2nd cap? in the remote switch box...then re-test.? ?Parallel a 3rd cap if required.? ?You should have zero heat..on any freq.? Dunno if the heath? box is? good up to 6m or not.? ? Jim? ?VE7RF |
Re: International shipping of Amplifier question L4B and a NIB HF-2500 Commander
Yep, they show up on the various hot rod forums I frequent and are right at the top of their game.
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The last shipment was a comple running low mileage Ford 460 and C6 still attached going into an early pickup. That ought to smoke up the tires really good unless taller gears are used in a heavy 9" axle. I used to install gears in the 2.50 range in 50's F-100's just to get traction. Those were common in 460 Lincolns and 2.47's in several small block vehicles. Carl Back to amps but I do love to drift into vintage vehicles! Thankfully King George III isnt on here ----- Original Message -----
From: Alek Petkovic vk6apk@... [ham_amplifiers] To: ham_amplifiers@... Sent: Thursday, June 27, 2019 8:19 PM Subject: Re: [ham_amplifiers] International shipping of Amplifier question L4B and a NIB HF-2500 Commander Yeah. Lotta rev heads downunder. On 28/06/2019 2:26 AM, 'Carl' km1h@... [ham_amplifiers] wrote: Find a local freight forewarder and get quots for ship and air. They combine-- From sunny Binningup Family Businesses: SP Electrical. www.spelectrical.net.au The Velvet Fox. Smart Design Electrical. Perth Interiors. |
Re: Series DC Blocking cap.
The choke should be doing most of the work and the cap very little. My HB and Ameritron switches all use a generic Z5 single .01 1KV right up to 1200-1500W on HF for decades of heavy use without failure.
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It often is hard to see internal choke damage but do an A:B resistance test with the other one: What is the model #? I can look tomorrow at the actual circuit. Carl ----- Original Message -----
From: kr9u@... [ham_amplifiers] To: ham_amplifiers@... Sent: Thursday, June 27, 2019 6:01 PM Subject: [ham_amplifiers] Re: Series DC Blocking cap. <<A total of .01 is more than enough, maybe a blown .02 was already removed in the past>> Thanks Carl, It's a stock box and the schematic shows it as I've described. There aren't any dissipation specs on the new cap - therefore the question. Jim - KR9U --- This email has been checked for viruses by AVG. |
Re: International shipping of Amplifier question L4B and a NIB HF-2500 Commander
Yeah. Lotta rev heads downunder.
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On 28/06/2019 2:26 AM, 'Carl' km1h@... [ham_amplifiers] wrote:
Find a local freight forewarder and get quots for ship and air. They combine --
From sunny Binningup Family Businesses: SP Electrical. www.spelectrical.net.au The Velvet Fox. Smart Design Electrical. Perth Interiors. |
Re: Series DC Blocking cap.
A total of .01 is more than enough, maybe a blown .02 was already removed in the past
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Carl ----- Original Message -----
From: kr9u@... [ham_amplifiers] To: ham_amplifiers@... Sent: Wednesday, June 26, 2019 10:09 PM Subject: [ham_amplifiers] Series DC Blocking cap. Slightly off topic, I am using an old Heathkit antenna switch that has the control voltages riding on the coax. The series DC blocking capacitor in the outside box has a piece chipped out of it. Maybe lighting, maybe power did it. It¡¯s an .02 uf 1.6 KV disk. I bought a .02uf 3 KV disk Vishay and installed it. If I run a 1500 watt carrier through it for about 15 seconds, it gets warmer than lukewarm. Warmest on 10 meters as I would expect. Would one expect the cap to be warm to hot after that amount of time? Any suggestions on what I should put in there? Curiously, the inside control box uses two of the .02 caps in parallel, not one as the outside box does. Jim ¨C KR9U --- This email has been checked for viruses by AVG. |
Re: International shipping of Amplifier question L4B and a NIB HF-2500 Commander
Find a local freight forewarder and get quots for ship and air. They combine multi items in one container for a lower cost.
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Ive shipped several amps as well as complete vintage V8 engines that way all over the world. Australia is a hot spot for engines! Carl ----- Original Message -----
From: k9uwa@... [ham_amplifiers] To: ham_amplifiers@... Sent: Wednesday, June 26, 2019 9:17 AM Subject: [ham_amplifiers] International shipping of Amplifier question L4B and a NIB HF-2500 Commander I need to ship a Drake L4B to a ham in VK6 land. The quotes I found from FedEx DHL etc are totally nuts. The buyer isn't in a hurry but somehow we have to get the shipping to something reasonable. So I thought where better to find out than from the Ham Amplifier group? So where do we get reasonable deals. One other question. I also have a brand new in the box Commander HF-2500 with a serial number on it of 0475. It has never had a plug connected to the power cord. Yes I am selling off a local SK's ham equipment for the widow. SK is Jule Franke W9TQA link to the sales AD on QRZ.com All help appreciated. Email to me k9uwa@... thanks 73 John k9uwa --- This email has been checked for viruses by AVG. |
Re: Econco now rebuilding Svetlana tubes !
That¡¯s useful to know, thanks. ?I have a stock of YU204s for the 4-1000 amp and 3CX3000s for that amp but could do with a spare Thomson TH376 or two if anyone knows where to source those?
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Dave G0OIL? On Thursday, June 27, 2019, 2:46 pm, jim.thom@... [ham_amplifiers] <ham_amplifiers@...> wrote:
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Re: International shipping of Amplifier question L4B and a NIB HF-2500 Commander
Curious, how much? Bob WE6C On Thursday, June 27, 2019, 7:24:39 AM PDT, jim.thom@... [ham_amplifiers] wrote: ? ##? Drake? L4PS? ( HV supply)? ?weighs? 45 lbs. Drake L4B? RF? deck weighs? 30 lbs.? 75 lbs total weight..... not including shipping boxes.? ## You? MIGHT? be able to ship via? USPS,? using? 2 x separate boxs.?? ##? I have? 4 x L4B's.....and? ?4 x mating? L4PS? hv supplies.? ?When? new, the L4B came in one box, the L4PS in another box, and? each tube came in it's own box....? 4 x boxes in total.? ?Dunno about the? ?2 x chimneys.? ?I believe the? chimneys each had a box.?? Jim? VE7RF? ? |
Re: International shipping of Amplifier question L4B and a NIB HF-2500 Commander
<I need to ship a Drake L4B to a ham in VK6 land. The quotes I found from FedEx DHL etc are totally nuts.? <thanks <John k9uwa ##? Drake? L4PS? ( HV supply)? ?weighs? 45 lbs. Drake L4B? RF? deck weighs? 30 lbs.? 75 lbs total weight..... not including shipping boxes.? ## You? MIGHT? be able to ship via? USPS,? using? 2 x separate boxs.?? ##? I have? 4 x L4B's.....and? ?4 x mating? L4PS? hv supplies.? ?When? new, the L4B came in one box, the L4PS in another box, and? each tube came in it's own box....? 4 x boxes in total.? ?Dunno about the? ?2 x chimneys.? ?I believe the? chimneys each had a box.?? Jim? VE7RF? ? |