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Re: Inrush filament current protection
Phil Clements
I looked. In our breaker box, all the ground wires and all the No electrical difference here; but if the breaker box is to be used as a sub-panel, you need seperate bus bars for the neutrals and grounds with a removable shorting strap between the two. Only in the main service entrance panel do the neutrals and grounds all strap together. I guess a few bucks are saved by leaving out the strap and insulation for the two bus bars if one has no intention of ever changing a main panel over to a sub-panel. (((73))) Phil Clements, K5PC |
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Re: Inrush filament current protection
FRANCIS CARCIA
I get along with my guy very well for the reasons you stated. Life is short and best to get the inspector out of it ASAP.
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"Robert B. Bonner" wrote:
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Re: Inrush filament current protection
Robert B. Bonner
Yeah some of these guys interpret the code differently¡ Have their own
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opinions. That¡¯s why there are lawyers and judges, hahahaha My local inspector considered the water pipe as the real ground¡ The ground rods as a supplementary ground. While this is incorrect it is supposed to be the other way around by definition. The water pipes in his argument are better grounded than the ground rod¡ The correct answers when dealing with ANY INSPECTOR are YES SIR and OK that¡¯s good to know, hahahaha. BOB DD ________________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of FRANCIS CARCIA Sent: Monday, November 13, 2006 12:01 PM To: ham_amplifiers@... Subject: RE: [ham_amplifiers] Re: Inrush filament current protection My building inspector did not want the ground wire in the meter socket. I ran conduit off the breaker panel to the rods. I also ran #4 over to the water main both sides of the meter. Then I showed him?the 4 #8s coming through the wall that go around the footing and through the yard. He smiled and said connect them also. Next I got some interesting lightning stories. gfz "Robert B. Bonner" <rbonner@...> wrote: -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of R L Measures Sent: Monday, November 13, 2006 9:41 AM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Re: Inrush filament current protection On Nov 13, 2006, at 4:48 AM, Robert B. Bonner wrote: Jim,Is not 240v standard in the United States? *** You can call it whatever you want, there is no actual voltage 220-230-234-240.. So you will sometimes see it referenced 220/240 which is the correct term. Or my favorite inside electrician's joke "220-221 whatever it takes" (From the movie Mr. Mom) It's a range power companies try to maintain between approximately 220 and 240 volts. (My second favorite electrician's joke is what do you need to know to be a plumber? Answer: S*** flows downhill and payday is Friday...) Mine runs almost 250 volts here most times. Just checked it it is 246.5 VRMS right now. residential circuits are two wire, the third wire is a GROUNDIf they connect together in the breaker box, is this really safe? ... ... *** Ask the guys who write the national electric code. I am but their local servant. :-) Ground should be ground... The equipment connected and the service entrance should all be grounded. My original power service in this house 42 years ago was grounded to water pipes. Then "they" also found that water companies would remove water meters from time to time, so now it is required by code to jumper over the water meter to maintain ground during that service. Lost a few meter technicians over time I suppose. Plus now current code requires at the meter socket you have quantity two 5/8" 8 foot copper ground rods 6' apart outside grounding the meter socket. Plus if you use non-metallic conduit between the panel and meter socket you need to pull a ground wire through there. "They" (The Power Gods) want NEUTRAL which is provided by the power company to be kept as close to ground potential as possible. The power company does not provide you a GROUND, They don't provide you technically 220/240 either, they provide two circuits of out of phase 120 on either side of a neutral; it is your responsibility to provide the GROUND and quite if by magic you make 240 Volts inside your panel. Consumers make all sorts of assumptions... Where actually as the consumer you are making the various voltages to power your house by yourself. You provide the ground... Which is the return path for the power company's 7200 Volts. (They only ground every other pole usually) and You make 220/240 inside your panel by wiring the out of phase 120's together. If you look at it that way... With Joe ham wiring away in his box not understanding what's actually going on, How safe is that? Maybe Europe's 250 scenario is a lot safer to start with? The bonding strap in a power panel is about a 10 gauge aluminum strap is all. Which is adequate if you don't ask ground to carry any current from gear. I have never heard of one of those melting in half except after a lightning strike, but it could happen if you drew power acrossed it. BOB DD R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org Yahoo! Groups Links |
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Re: Inrush filament current protection
Robert B. Bonner
See below
________________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of KR4DA Sent: Monday, November 13, 2006 10:31 AM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Re: Inrush filament current protection 210-250v depends on the utility company... My experience and I am not certified.... read any basic book on it..... I have done most of the wiring around my house.. a well and the pool and the 24x30 shop with welders etc..... up to 220v is not rocket science.. Should be four wires. 1. RED 120v one phase side 2.BLACK 120v one phase side 3. WHITE neutral 4.plain copper wire. **** Red and Black are both acceptable colors to use, they don't have to be one red and one black. You should be very careful if you get into 3 phase at all as they become different meanings. When in YES you can use the WHITE 120v BLACK 120v and the plain copper wire as GND. But you might confuse a person thinking this is a 110v wiring as white is NOT supposed to have 110v on it... WHITE is supposed to be NEUTRAL. **** You can pull a standard Romex line with white - black and bare ground wire, however where the white is exposed YOU MUST cover the white with Black tape to TELL SERVICE PEOPLE that this is the other leg of a 220/240 circuit. This is allowed. I do know they there is a chassis connection and a ground connection on some electorical devices where this is need I am not sure. I have seen some old TUBE stuff that required this. Usually the white and plain copper are connected together at the BOX. BUT the white has one bus bar and the plain copper has another. If you look in the power box the power company neutral is tied to a COMMAN BAR this is where the WHITES are connected... BUT then running from the power company neutral is usually another BAR going to a strip where the plain copper wires are attached. There is no actual really separation on these GND and neutral bars... It's a just do it this way thing. **** Yes you are correct there are separate busses in the panel. This is because neutral and ground are not supposed to be the same thing, however they are tied together. NEVER confuse them as the same thing as they are never the SAME even if they appear to be tied together. The white wire is a current carrying conductor and the green or bare is not. Is this over kill? Not if it saves your life. This is done to standardize power panels. Sure as S*** somebody here is going to pop a cover off a 3 phase panel someday and kill himself if he doesn't learn what things are and why... When you get into HIGHER more complicated phases of power 440 880v then the GND and NEUTRAL provided by the power company are critical. But not for 220v requirements. Incorrect, but this is the Consumer fallacy I'm trying to cure. *** Remember I've already said the power company doesn't provide GROUND you do. Its like GUNS don't kill people - People kill people.. While you can justify "They are all the Same" this is a poor justification. The rules of electricity are developed to kill as few people a year as possible. When you start treating things the same is when you will become a statistic. Let's respect the CORRECT definitions and uses of these conductors. (Whether I can convince you they are different or not) Some day your whole house will be full of ARC FAULT and GROUND FAULT Breakers. They are now becoming code... When that day comes you'll be in a world of hurt otherwise. BOB DD AKA "Electro the Magnificent" I didn't make that up BTW, I was dubbed that by a past employer. OH yeah and if you want a violent code argument I'll give you Don "The CODE" Coder's phone number he even drove me nuts with code discussions, I'm a pussy cat in comparison... :-) RB BWAAAHAHAHAHAHA! R L Measures wrote: On Nov 13, 2006, at 4:48 AM, Robert B. Bonner wrote: Jim,Is not 240v standard in the United States? residential circuits are two wire, the third wire is a GROUNDIf they connect together in the breaker box, is this really safe? ... ... R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org -- de KR4DA Bob Middleburg, FL HK0/KR4DA J79DA FG/KR4DA |
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Re: Inrush filament current protection
On Nov 13, 2006, at 8:30 AM, KR4DA wrote:
210-250v depends on the utility company...Not in California, it's set at 228v to 240v by the PUC. My experience and I am not certified....I do not believe everything in any book. I have done most of the wiring around my house.. a wellIt's required in this neck of the woods. BUT the white has one bus bar and the plain copper has another. If you look in the power box the power company neutral is tied to a COMMANI looked. In our breaker box, all the ground wires and all the Neutral wire connecct in one bus bar. How would it be different if there were two bus bars that are connected by a bus-wire? ...cheers, Bob R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: NOS cermic-metal tube burn in
What is the screen PS V?
What is the anode PS V? What Class? On Nov 13, 2006, at 7:34 AM, Hsu wrote: Hi, There are two Chinese FU-251F(4CX250B) cermic-metal tubes, they are new but storge for very long time. The output power only 200-250W( a pair), Could someone cal tell me how to solve this problem?Is it means I have to drop them in the junk box?R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: Inrush filament current protection
FRANCIS CARCIA
My building inspector did not want the ground wire in the meter socket. I ran conduit off the breaker panel to the rods. I also ran #4 over to the water main both sides of the meter. Then I showed him?the 4 #8s coming through the wall that go around the footing and through the yard. He smiled and said connect them also. Next I got some interesting lightning stories. gfz
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"Robert B. Bonner" wrote:
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Re: Inrush filament current protection
Robert B. Bonner
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-----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of R L Measures Sent: Monday, November 13, 2006 9:41 AM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Re: Inrush filament current protection On Nov 13, 2006, at 4:48 AM, Robert B. Bonner wrote: Jim,Is not 240v standard in the United States? *** You can call it whatever you want, there is no actual voltage 220-230-234-240.. So you will sometimes see it referenced 220/240 which is the correct term. Or my favorite inside electrician's joke "220-221 whatever it takes" (From the movie Mr. Mom) It's a range power companies try to maintain between approximately 220 and 240 volts. (My second favorite electrician's joke is what do you need to know to be a plumber? Answer: S*** flows downhill and payday is Friday...) Mine runs almost 250 volts here most times. Just checked it it is 246.5 VRMS right now. residential circuits are two wire, the third wire is a GROUNDIf they connect together in the breaker box, is this really safe? ... ... *** Ask the guys who write the national electric code. I am but their local servant. :-) Ground should be ground... The equipment connected and the service entrance should all be grounded. My original power service in this house 42 years ago was grounded to water pipes. Then "they" also found that water companies would remove water meters from time to time, so now it is required by code to jumper over the water meter to maintain ground during that service. Lost a few meter technicians over time I suppose. Plus now current code requires at the meter socket you have quantity two 5/8" 8 foot copper ground rods 6' apart outside grounding the meter socket. Plus if you use non-metallic conduit between the panel and meter socket you need to pull a ground wire through there. "They" (The Power Gods) want NEUTRAL which is provided by the power company to be kept as close to ground potential as possible. The power company does not provide you a GROUND, They don't provide you technically 220/240 either, they provide two circuits of out of phase 120 on either side of a neutral; it is your responsibility to provide the GROUND and quite if by magic you make 240 Volts inside your panel. Consumers make all sorts of assumptions... Where actually as the consumer you are making the various voltages to power your house by yourself. You provide the ground... Which is the return path for the power company's 7200 Volts. (They only ground every other pole usually) and You make 220/240 inside your panel by wiring the out of phase 120's together. If you look at it that way... With Joe ham wiring away in his box not understanding what's actually going on, How safe is that? Maybe Europe's 250 scenario is a lot safer to start with? The bonding strap in a power panel is about a 10 gauge aluminum strap is all. Which is adequate if you don't ask ground to carry any current from gear. I have never heard of one of those melting in half except after a lightning strike, but it could happen if you drew power acrossed it. BOB DD R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org Yahoo! Groups Links |
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Re: 3-500Z socket.... Johnson vs Eimac
Peter Voelpel
Rich,
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it says 0.082" at sea level and 500W dissipation 73 Peter -----Original Message-----
The Eimac spec sheet says 0.82" at sea level. |
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Re: Inrush filament current protection
KR4DA
¿ªÔÆÌåÓý210-250v depends on the utility company...My experience and I am not certified.... read any basic book on it..... I have done most of the wiring around my house.. a well and the pool and the 24x30 shop with welders etc..... up to 220v is not rocket science.. Should be four wires. 1. RED 120v one phase side 2.BLACK 120v one phase side 3. WHITE neutral 4.plain copper wire. When in YES you can use the WHITE 120v BLACK 120v and the plain copper wire as GND. But you might confuse a person thinking this is a 110v wiring as white is NOT supposed to have 110v on it... WHITE is supposed to be NEUTRAL. I do know they there is a chassis connection and a ground connection on some electorical devices where this is need I am not sure. I have seen some old TUBE stuff that required this. Usually the white and plain copper are connected together at the BOX. BUT the white has one bus bar and the plain copper has another. If you look in the power box the power company neutral is tied to a COMMAN BAR this is where the WHITES are connected... BUT then running from the power company neutral is usually another BAR going to a strip where the plain copper wires are attached. There is no actual really separation on these GND and neutral bars... It's a just do it this way thing. When you get into HIGHER more complicated phases of power 440 880v then the GND and NEUTRAL provided by the power company are critical. But not for 220v requirements. R L Measures wrote:
-- de KR4DA Bob Middleburg, FL HK0/KR4DA J79DA FG/KR4DA |
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Re: 3-500Z socket.... Johnson vs Eimac
On Nov 13, 2006, at 2:30 AM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:The Eimac spec sheet says 0.82" at sea level.requires a high-pressure centrifugal blower, and Ham amps used an And that's for 500/1000 w CCSOpinions count way less than manometer measurements. Heck......The nickels are glued down about 5" apart.corners along one edge is light enough to rise automatically withA square of varnished cardboard with two nickels glued to theflap that hinges up to let the air out. It just doesn't look as They are correct -- it's called Stephan's Law and the power radiatedred radiation?RICH SEZ... So objects that glow red-orange do not exhibit infra-### here's the interesting bit. Eimac states the glass tubescool by infared radiation.... well my natural gas fireplace puts is a function of the object's Temp raised to the 4th power. I can put my handsYou would have done somewhat better at this point had you put your hands on the mouse and clicked Send. . on theThe SB-220 has a ¡Ö600W HV transformer. Hello! cheers, Jim .R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: "Father Measures"
On Nov 13, 2006, at 3:53 AM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:Hardly, Jim. I know too much about history to ever join any organized religion.make a good priest. Maybe they were joking?... cheers R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: Inrush filament current protection
On Nov 13, 2006, at 4:48 AM, Robert B. Bonner wrote:
Jim,Is not 240v standard in the United States? residential circuits are two wire, the third wire is a GROUNDIf they connect together in the breaker box, is this really safe? ... ... R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: Inrush filament current protection
Robert B. Bonner
Jim,
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I know several years ago a friend sent me some copies of the posts on AMPS when I wasn't a member. There were comments rather heated regarding POWER SERVICES and AC wiring to amps. I will end that quickly here as I won't tolerate incorrect info to pass me by. You are a smart guy, very knowledgeable and have some good experiences but let's define power services / wiring correctly to avoid any errors. You and I are saying the same things but differently. Separated by a common language. I worked three years as an electrician... Knew my business. Standard 220V residential circuits are two wire, the third wire is a GROUND (Green) not a neutral. Most dryers are 2 wires plus ground here. You wire your Ameritron its two wires plus a ground. If you have a 4 wire 220 circuit including Power Cord and a 4 conductor plug... Two blacks a white and a green. You have 220 plus neutral. This will give you 220V via two 120 circuits and a ground. This is a direct extension of your panel service. Most residential 220V items don't use 4 wire. Not to be confused with 3 Phase which is all different colors / uses. In residential services in the states we tie the NEUTRALS and the GROUND Buss together in the main panels, however that NEVER by definition makes them "the same thing". Neutral is Neutral and Ground is always Ground. Try switching them in a ground fault circuit and the breaker will blow. The green wire should NEVER conduct current. SO if you are utilizing a 120 volt transformer somewhere in your homebrew for a control circuit or filament you should also be utilizing either a 220-120V step down transformer in your construction or a 4 wire 220 circuit to meet code... This is why large commercial HF power generators like the Henrys (even the 8K) have 220-120 step down transformers inside them. Others use 220V filament transformers not 120 to meet the electrical code... Why don't they use all 220 transformers? New regs requiring both legs to blow when one goes. They put gangbared main breakers on the gear, but utilize 120 volt fuses for all the other small circuits to save money. The 220-120 step down is cheaper to fuse than dual breakers on all circuits. Now will it work your way? That is 120V circuits wired to one side of the line? YES... Does it meet code? No... FYI The base Alpha 77 wasn't UL approved. It had a hot ground wire. There was a higher cost version that had a step down transformer in it if you REQUIRED a two wire circuit. That's mentioned right in their manual. You are correct on all the other points. The separate CB's wouldn't fly today without a tied together gangbar to kill both sides of the AC line. A Grandfathered in system does not make it a good system. :-( That's what I was referring to as CHEATING The System. Breaking the Electrical Code. Since we are basically saying the same thing differently... We have no argument. BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of pentalab Sent: Monday, November 13, 2006 3:41 AM To: ham_amplifiers@... Subject: [ham_amplifiers] Re: Inrush filament current protection --- In ham_amplifiers@..., "Robert B. Bonner" <rbonner@...> wrote: RIGHT NOW that had me thinking the same thing. ### huh ? AS long as you have a relay/contactor/ ckt breaker that opens OFF BOTH sides of the 240v line... anything beyond that is a moot point...and legal. BEWARE... if using fuses on the primary.... they HAVE to be 240 V rated... NOT 120 V rated. Here's why. IF only one fuse in one leg of the primary blew open... and the 2nd fuse in the other leg was intact....you could end up in a situation where 120 v is fed to one side of the plate xfmr primary.... where it will simply pass throught the typ .08 ohm dc resistance primary... then back to the OUTPUT side of the blown fuse.[call this leg #2] Meanwhile... on the INPUT side of the blown fuse.... you still have 120 V [coming from leg #1.] The potential difference across the blown fuse in leg #1 will be ...240 V. IE: with EITHER fuse blown [but only one], you will have 240 v across an open fuse.... so DON'T use 120 V rated fuses in either leg of a 240 v LINE. ### ALSO BEWARE.... some amps like the L4B... use two SEPARATE circuit breaker's... one per hot leg... and NO tie bar between em. These are usually the type that resemble a 3agc fuse holder.When these type of breakers open up... they extend outwards. wire plus neutral. ### partially agreed. ALL wire now comes with a bare or insulated grnd...whether u want it or not. The grnd is NEVER considered any more in the wire count. So, you either ask/order 2 conductor wire.... OR 3 conductor wire. 2 x conductor wire comes with a grnd... so total wires = 3. 3 x conductor wire also comes with a grnd... so total wires = 4. IE: you ask fo 3 x wire XXX ga.... u get a total of 4 x conductor's. practices you could get by with only 1 resistor in the step start. #### The electrical code will state on a 240 v circuit you will require a TWO pole breaker..and/or a TWO pole relay/contactor... to open off BOTH sides of the line. After that.. they could care less if u install a 12.5 ohm resistor in EACH hot leg... or a 25 ohm resistor in just ONE hot leg. Putting a resistor in both legs is a waste of effort. It's total LOOP resistance we are concerned with here. like a filament transformer that runs on 110 you would want to have 2 resistors in the step start. ### Agreed. BUT.... on an amp like the L4B.. and 99% of em... that have a SEPARATE fil xfmr.... the fil xfmr will ALWAYS have it's own dual 120 v primary's.... which can be wired in parallel for 120v... or in series for 240 V. The only exception to this.. would be if in a condo with 208/120V wiring per suite. You can then run 208 V into the plate xfmr [wired for 240V.. so u end up with slightly less plate V].... and run 120 V to the fil xfmr [wired for 120V... so fil gets correct V] ### IF, indeed one had a fil xfmr that ONLY ran on 120v.... then, you would have to ensure that the hot leg feeding the fil xfmr.. came from the SAME side of the 240 v line.... as your single step start resistor.... so when step started... you step start BOTH the HV supply AND the fil xfmr... at the same time...from the same source. ### No you wouldn't. That could only happen if one side of the 120V fil xfmr [or any other 120 v device] was tied directly to the chassis.. instead of the neutral. That isn't going to happen.. since it's not allowed... would violate every electrical code in North America. On a similar note... you NEVER bond the neutral to the chassis.... that also violates every electrical code in NA. The ONLY thing bonded to the chassis is the grnd wire. With any shorts from either side of line to chassis... the grnd wire handles the full fault current. ### On circuits which require a huge 240 V load... like a HV supply... but only a tiny load for the 120 V load... like say a 120 V blower... some tiny xfmr's for a T/R supply, etc... then it would be ok to use a smaller neutral.... as long as the neutral could handle the entire fault current... IF a line to neutral short occured. EG: 2 ga wire for each hot leg... and a 100 A main breaker in panel... but only 6 ga wire for the neutral.... and also 6 ga wire for the grnd. ### You see that in the Henry 8 k manual. They do that to run the 120 v Dayton blower. In EU/UK... they don't use a 3 wire 220 v line. They only have 2 x wires from the pole pig... with 220 v across em. One side of the line is bonded to earth ground... so one leg is hot... the other leg is valled neutral. That way, they only have to fuse the ONE hot leg... and any switches, relays, etc, are only required to be single pole types... for the one hot leg. As per the 8K... when you look up the Dayton blower part number they spec in their parts list in their manual.... and cross reference it to the Dayton blowers on Grainger's website... turns out it's the 230 V version of the same blower... and in fact, the 240/120 V step down xfmr shown in the schematic and also the picture drawings.... doesn't exist. ## Notice on 240 V clothes dryers... they always include a neutral... to run the 120 V blower. Seems stupid to me. They shoulda just used a 240v blower... and could have eliminated the requirement for a neutral..... just like a 240 v hot water tank.... none of which have a neutral... since the heating els run on 240 V only. Another option is 4 wire circuitry where you have 220 plus neutral and ground. What a pain with the outlets etc...### what's the problem with the outlets ??? A 30 A dryer outlet comes with 2 x hots, one neutral... one gound. A 40 A stove is exactly the same thing. Ditto with 20 A circuits. brewing does it really matter? NAW it will turn on and work. ### with HB HV supplies... you don't need an outlet. You just hardwire the 2 ga wire directly to the line side input of the front or rear panel mounted breaker. OR hardwire the 2 ga wire directly to the jumbo contactor input..... either way... you still have the breaker in the main panel that feeds this mess. You can buy 75/100/150/200 A outlets... cost a small fortune. You don't need em.... just hardwire the big wire in..... and when working on the amp.... kill the breaker in the main panel. IF the HV supply/amp needs to be rolled over to the bench... just disconnect the 4x wires at the HV/amp end. prettier, double pole relay, pair of resistors, double pole relay all in line. Nice pretty yellow adjustable time delay relay. ### Here's what I do. I use 25 ohms in one leg only... and only one contactor to short out the resistor. The kicker is.. I use a pair of paralled 50 ohm resistor's to make up the 25 ohms ! If one resistor ever opened up... the 2nd one [albeit 50 ohms] is still in the circiut. That way... I can never shunt an open single resistor with the step start contactor... and slam a huge load on the diodes.... IE: no step start at all... which would be a disaster with 100-200 uf C input filter. These large metal finned resistor's you see made by DALE and other's, works perfectly for the step start R. Just bolt it to metal chassis anywhere. Cuz of our magnetizing current.... I use a min of a 100w - 200 W rated units... EACH. You will have the entire 240 V dumped across em when you 1st hit the switch. When everything settles down... I still have 2 A of magnetizing current flowing through em..[100/200 w]... then they get shunted. ## I also use the yellow /white adjustable Time delay relay. The TD relays are all DPDT 10 A contacts.... which are used to activate the coil of the step start contactor. The big step start contactor has loads of AUX contacts... which are wired to the amp key line.... ditto with main incoming contactor.... so you can't key the amp unless all the contactor's are actually operated. We use loads of 120 v neons as well.. status lamps... to tell us instantly, where a problem is.. works slick.. if and when it comes time to trbl shoot anything. A row of 3agc fuses [and more neons on the output sides of the fuses] are the various feeds for the blower, TD relays, small xfmr's for T/R relays, contactor's etc. ### On the big stuff.... we use a separate Time delay for the fil xfmr... which has it's own step start resistor/ variac, etc. The fil TD is set for 8-10 seconds.... the HV delay is set for 15- 25 seconds. The blower over run TD is set for 15 mins. -also have an airflow vane/ switch, retrofitted inside the blower. Contacts of the airflow switch are wired to the coil of a small relay.... whose contacts open off the 240 V to the fil xfmr. The last thing you want is no air to a tube... esp when it's 30' away... in another room. The slick thing about this setup is... IF the commercial AC power goes off.... everything shuts down. When the power comes back on.... everything just goes through it's normal step start sequence etc. You can't key the amp... until it's all finished. Later... Jim VE7RF [mailto:ham_amplifiers@...] On Behalf Of Garry Drummondresistor in both sides of the 240 volt line for inrush current protection orwould a single resistor of adequate size in one leg do the job? I amspeaking of the typical amplifier running a pair of 3-500's. Yahoo! Groups Links |
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Re: "Father Measures"
pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
make a good priest. Maybe they were joking?... ### I can just see it now.... "Father Measures" ... up on the mound.. preaching a fire and brimstone lecture about..."parasitic hell"....to us globar heathen's, with the ARRL bible in one hand.... and a wouf hong ...made of solid Nichrome in the other hand. Quick... run for your lives ! The sky is falling. later... Jim VE7RF R L Measures, AG6K, 805.386.3734 |
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Results of removing grid fuse + cathode fuse
pentalab
OK, here's the deal.
I had my buddy with the 3x6 remove the fast 750 ma grid fuse from the 3agc fuse holder... then try and apply 800w of drive. INPUT SWR on the big amp goes sky high.... and then the IPA [87-A] kicks itself offline..... leaving just the MK-V... which then see's the same sky high swr.... and the yaesu MK-V of course throttles back to zero watts output. .... good. Grid fuse was re-installed. Next up... the 3A 3agc cathode fuse was removed. Again, 800w of drive applied. Exact same results..... sky high input SWR... etc. Note... the grid fuse results ONLY happen, if their is NOTHING placed across the grid fuse holder.[no path for DC grid current, amp can't be driven]. Originally we had a 100 K 3 w mof reistor in parallel with the grid fuse holder. Upon grid fuse removal... and drive applied.... we were down to 2kw out... instead of the usual 12 kw. Input swr went from 0 watts reflected, to 60 w reflected [800 w forward = 8 % reflected.=low swr] We could also pull grid current.... but a LOT less. What was happening is this. The V drop across the 100 k mof resistor [with grid fuse removed] was directly in parallel with the reverse connected 6 A diodes... wired between chassis and B- The V drop across the 100 k resistor turned on the diode.... and grid current would flow via this new...alternate path. Meanwhile, the V drop across the 100 K resistor was still being applied to the cathode... and heavily biasing the amp into class C. So, the 100k resistor across the grid fuse ISNT'T needed.... don't install it. Rich suggested a MOV in parallel with the grid fuse holder. That's not needed either. The RVS connected diodes between chassis and B- are STILL in parallel with the grid fuse holder. Later... Jim VE7RF |
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Re: Can a ..power factor correction cap be used on the input of a Plate Xfmr ??
pentalab
--- In ham_amplifiers@..., "craxd" <craxd@...> wrote:
### Yes.. pse do. It would be much appreciated as I have hit a dead end here. That value though seems way to much at 35 uF for this. Placed across the primary leads, it will start looking like a short or a leak if big enough. That's why your seeing an increased current. The cap is causingmore current to be drawn or mag I + cap I. #### My conclusion is... since pri current went from 1.8 A to 2.3A.... Cap current added another .5 A All transformers have magnetizing current which is low compared to their output power.the higher the flux density its ran at, the higher it will be.### agreed. Point here is that we spend most of the time on RX... and 2 A of magnetizing current = 480Va. Nothing we can do about it. As far as power factor goes... that might be something we can do something about. IF the correct size pwr factor cap can be installed.... and the cap still draws current on RX.... then it would be easy to switch out the cap on RX... with a vac relay. For this type transformer service, the power factor should be about 0.95 or so. ### I'd say the power factor on a large C input filter would be at least .9 EG: u want to suck 900 w.... u need 1000 va. .9 x 1000 = 900w. Also 1000va/900w = 1.11 or 11% more primary current required... due to power factor. Then you have to factor in core losses.. another 10 %. So to convert DC input WATTS to PRIMARY VA.... u gotta multiply dc input x 1.22 I measured it... that's excatly what I get on a hypersil C core... like atyp pole pig... or a Dahl product. On My 80 lb hammond plate xfmrs [high reactance EI types... made for choke input.... but configured as a C input filter] you gotta multiply dc input watts by 1.35 Other xfmr's are worse still. ### add more filter C... and power factor gets even worse still. If the ripple is low where you want it, I wouldn't worry about adding anything else that may draw more current.### I'm fine with the ripple... it's under 1%. I'm worried about the power factor.... and if something can be done.,.. great... if not.... no big deal... since nobody is on TX for that long anyway.... with vox/ roundtables etc. ## Being able to do something about 480 va CCS... caused by magnetizing current would be nice. I suppose one could just shut off the HV supply... if you knew you were gonna be on RX for an hour... and just leave the fils on. Only a few seconds to get the HV back online.... then ph Nuke station #6... and tell em to pull the rods out. Later..... Jim cap tothetry it myself. It gets installed directly in parallel with thepri of the plate xfmr. [this is for a C input HV supply]. wentwrong value. What I did notice was the magnetizing current capsup on the pole pig... from 1.8A to 2.3A ! The magnetizing upresistor]to max V. [u always have current flowing through the drop withThe plate xfmr is always sucking magnetizing current... even becausenothing connected to the secondary. ofdrawsload. The idea I had was to use a small possibly sped up vacthe excess1.8 A. My electrician buddy sez they never oversize vault biggermagnetizing current. HVDahl draw LESS magnetizing current than the smaller 120 lb poleThese secC input filter. Maybe I'm confused here... but it appears theloadis not the XL load of the xfmr... but the HV C filter on the mightside ? behasfruitless....... or maybe it works on TX... but correction cap aboutto be switched out on RX. IF it works... how do you go throughsizing the correction cap ?.... and how much current flows the correction cap ??? |
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Re: ARRL - Political - was: Filament Voltage regulator
On Nov 12, 2006, at 5:42 PM, FRANCIS CARCIA wrote:
In West Hollywood, this would be considered a perquisite. None of this was news to me after learning that.Correct, Frank, which is why they adopted the priestly vow of not to do women 9-centuries ago. It is all about money (sick).Right, and Bernard Law gets an allowance of c. $12,000 a month. ... ... ...R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: 3-500Z socket.... Johnson vs Eimac
pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
requires a high-pressure centrifugal blower, and Ham amps used an ordinary centrifugal blower. pressure.### See my note above. A 3-500Z only requires a .08" h2o RICH SEZ... Correct, but Eimac's 0.82" water column spec is the pressure differential across the socket, and that usually means a fairly noisy blower. ### The actual spec for a 3-500Z is 13 cfm @ .13" h2o...... or 26 cfm @ .13"... for a pair. And that's for 500/1000 w CCS anode diss. Now .13" pressure is zip imo. Heck... the requirements for a SINGLE 3CX-800A7 are 19 cfm @ .5" A 4CX- 250R is 6.4 cfm @ .59" A blower capable of .13" h2o is NOT noisy. The puny blower in the L4B is dead quiet.. a lot quieter than the 1" diam tiny fan in my outboard 30 vdc supply for the yaesu MK-V. [the noise in the mk-v power supply is from the slots in the cab... not the actual 1" diam fan] corners along one edge is light enough to rise automatically withA square of varnished cardboard with two nickels glued to theflap that hinges up to let the air out. It just doesn't look as the airflow passing through an 8170. When the amp is off the cardboard flops down, keeping spiders from constructing webs on the insides. ### well, at least you got 2 x nickels to rub together ! red radiation?RICH SEZ... So objects that glow red-orange do not exhibit infra-### here's the interesting bit. Eimac states the glass tubescool by infared radiation.... well my natural gas fireplace puts ### If a 3-500Z is suppose to cool partially via infrared radiation... I think they are full of it. I can put my hands on the left side cabinet... [which is flat black... in and out]... and it's stone cold... and also has zero air on it. You can take the cab right off... and put ur hand [carefully] on the insides anywhere... and feel no heat from the infrared radiation. The outsides of the chimney's are hot [dead cxr, tubes red]... but that's from a lack of air. The puny blower in the L4B is good for 600W CCS anode diss... NOT 1kw. The point is.. the infrared radiation is not heating anything else up in the cabinet. The Fluke 62 IR confirms this. ### Another point here. The 3CX-800A7 has got 60% MORE anode diss than a 3-500Z.... but only requires 46% more CFM than a 3- 500Z. So much for..."cooling" by infrared radiation. ### Rich... if you operated the SB-220 at 1500W out RTTY for 1 hr... you wouldn't have enough cooling on the tubes. You would have to use a real noisy fan. [asuming a real pwr supply, and loads of air on tank components... like that flaky bandswitch]. The point here is the fan set up in the SB-220 is designed for 600 w out cw operation [400 w peak anode diss, 200 w CCS].... and 1200 w pep out on ssb [800 w peak anode diss, maybe 400-500 W CCS] that's it.... and that asumes you are not TX'ing all the time either. Later... Jim VE7RF ...R L Measures, AG6K, 805.386.3734 |
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