RE: [AMRadio] Screen Regulator Circuits, 20a, etc.
Dave, We you able to work around the word-wrapped link problem in my original email? Jim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of David Knepper Sent: Wednesday, November 19, 2003 5:02 AM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Screen Regulator Circuits, 20a, etc. Jim, the websites that you gave cannot be downloaded. Thank you. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Screen Regulator Circuits, 20a, etc.
Jim, not quite sure what you mean? Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com - Original Message - From: Jim candela [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, November 20, 2003 7:01 AM Subject: RE: [AMRadio] Screen Regulator Circuits, 20a, etc. Dave, We you able to work around the word-wrapped link problem in my original email? Jim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of David Knepper Sent: Wednesday, November 19, 2003 5:02 AM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Screen Regulator Circuits, 20a, etc. Jim, the websites that you gave cannot be downloaded. Thank you. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Screen Regulator Circuits, 20a, etc.
Jim, they work now. Thanks. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com - Original Message - From: Geoff/W5OMR [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, November 19, 2003 8:35 AM Subject: Re: [AMRadio] Screen Regulator Circuits, 20a, etc. Jim, the websites that you gave cannot be downloaded. Thank you. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com Worked for me. you have to re-join the link... or, at least know that the rest of the link, is on the next line ;-) My two circuits are here: Tube version: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/CE_20A_ QRO_Power_Supply.jpg Solid State version: http://pages.prodigy.net/jcandela/Sherwood_S8000/HV_REG/SS_HV_VOLTAGE_REGULA TOR.jpg The ripple from it is unmeasurable (with my equipment), and dynamic load response is excellent, although I cannot remember exactly what the results were, as that was last winter. The rest of my 20a info on the web is at: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/ If the links are still broken, then cut-n-paste the first line of the link into your browser (you can copy the whole link, but if it's split, you'll only get the first line, anyway) then past the 2nd line. Why does it do that? I really don't want to get into an OS bash-session. 73 = Best Regards, -Geoff/W5OMR ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Screen Regulator Circuits, 20a, etc.
JimWe you able to work around the word-wrapped link problem in my original email? Dave Jim, not quite sure what you mean? He's wanting to know if you were ever able to click on the links and make 'em work? The original message was: == Hi Guys, I have been working on two HV regulator circuits in the past year where I needed +375 volts at up to 100 ma. In the first case I had 600 volts to start with, so I used a tube circuit. In the second case, all I had was about +430 which dips to about 390 at maximum output, and reduced AC line voltage, so I went solid state. My two circuits are here: Tube version: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/CE_20A_QRO_Power_Supply.jpg Solid State version: http://pages.prodigy.net/jcandela/Sherwood_S8000/HV_REG/SS_HV_VOLTAGE_REGULATOR.jpg The first circuit shows my complete power supply in my Central Electronics 20A QRO #2 rig. I used a pair of 7591's in the RF final to make up to 12.5 watts AM output, or about 55 watts PEP SSB output. I ended up with a 6W6 in the series regulator as it had more emission than a 5V6, even though the 6W6 only had 5 1/2 volts on the filament. This regulator is always at +374, hot, cold, month after month. The ripple from it is unmeasurable (with my equipment), and dynamic load response is excellent, although I cannot remember exactly what the results were, as that was last winter. The rest of my 20a info on the web is at: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/ 73 = Best Regards, -Geoff/W5OMR
RE: [AMRadio] Screen Regulator Circuits, 20a, etc.
Brett, Yes I know that circuit. I looked a lot at some of Bill's circuits when I did my first regulator, and what I used has parts in it stolen from Bill. I found that I got tighter regulation with the 6AH6 error amp tube over the 6AU6. I also had the problem where every time I turned it on, the regulated B+ was at a different voltage (within a 5 volt range). Once on the voltage was solid until cycling power, and then it would jump to a new stable value. Digging through some reference material, I read that the OA2, OB2 are famous for this, and that is why more precise regulators of that vintage used a 5651 reference tube. I experimented some, and the capacitor I placed across the OA2 seemed to fix the problem completely, and that regulator holds the voltage like glue now. There is a maximum value of capacitance that these VR tubes can handle before they start acting like a RC oscillator. Another issue is which side of the regulator do you pull current from to light up the VR tube? I used the output side as it seemed to provide better regulation (load and line), and lower noise output. The drawback of course is that the regulator series pass tube must give up some percentage of it's available current to support the VR tube. I had about a 2X margin of available current to needed output current, so this was a good compromise in my instance. I also played with sampling Vin and Vout at a certain ratio to feed the bias voltage to G1 of the series pass tube. There seems to be a point where the ripple rejection of the regulator goes through a peak, and the output noise nulls. Anyone ever play with that? I sure like the 6W6 as a series pass tube. I got 5 of them NOS in box for $9.99 from a Ebay auction. Look at the plate curves in triode connected configuration. They are very stout tubes for the size, and money (little demand for these so they are cheap!). Brett in your case I wonder what your Vin, and Vout voltages are, and what is the minimum Vin - Vout at Maximum load current that the circuit can accommodate before going open loop (out of regulation)? Regards, Jim Candela WD5JKO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Brett Gazdzinski Sent: Wednesday, November 19, 2003 8:41 AM To: amradio@mailman.qth.net Subject: RE: [AMRadio] Screen Regulator Circuits, 20a, etc. I use a circuit out of the Bill Orr handbook that uses a big Vr tube, some small octal tube, and a big triode (6as7??). I forget the tube numbers, but the circuit is adjustable voltage output, I use it on the screens of my 4cx250b modulator tubes. Works very well, and has been 100% reliable for over 10 years now. The 4cx250b mod deck is the one of choice for the 813 pair, its very clean and runs 600 watts in ab1, so the circuit gets a good workout. Brett N2DTS AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] Screen Regulator Circuits, 20a, etc.
Jim, The circuit I built is in the red or yellow Bill Orr books, uses octal tubes, including the big triode pass tube (6sa7??). I have the output metered on the front panel of the modulator, and it ALWAYS stays at what I set it at (350 volts). Crazy, but I just pulled some (used) tubes out of the junk box and plugged them in, and the circuit has been working without problems for well over 10 years now, without a single crap out! I don't know about the regulation, the meter never moves, but I don't think the 4x150 screens draw a lot of current. From memory, the input voltage is around 500 volts, the range the regulator will work in is somewhat limited according to Bill Orr, but the circuit works great for what I do with it. There is a limitation in the filament to cathode insulation of the big triode pass tube according to Bill Orr... It was such a cool design, I had to build it, plus, its adjustable, and I put its control on the front panel, along with the bias adjustments for each tube(seperate). The 4x150/4cx250 tubes are interesting in that you can variac the plate voltage between 1000 and 2000 volts without changing any other setting (bias or screen voltage). A great way to play with mod power out and impedance Having the adjustments on the front panel allows experimentation with different values of bias and screen voltage. Cool tubes, 600 watts of clean audio in AB1, drive it with a 12ax7! I drive it with the audio power amp into a LS transformer, so I can use the same audio setup with all the transmitters, but you can drive the grids with almost anything. I suspect the screen voltage regulation is quite important as far as the distortion goes, and many tubes like the 4-400 can sound good if great care is taken, otherwise, they sound like crap. I could never get 6146 tubes to sound good tho, even with regulation and feedback. There are likely better ways to do it these days, but the design was so cool, I had to build it. I dislike solid state components at higher voltages, as much as I dislike running electrolytic over 400 circuit volts. Yes it works, but I don't think its as reliable as tubes or oil filled caps. Except for arcing over a feed through insulator between the mod and RF cabinets in the 813 rig, all my homebrew stuff has been 100% reliable, well over 10 years for the 813 pair and mod decks for that, about 2 years for the new push pull 812 deck. Not even a single tube has gone bad in anything in the shack, the home brew or the commercial stuff (Collins, Scott, Hallicrafters, R390a, Gonset G76, etc) There are very few solid state components in my stuff, only diodes really...those HV brick diodes and so on. Brett N2DTS Brett, Yes I know that circuit. I looked a lot at some of Bill's circuits when I did my first regulator, and what I used has parts in it stolen from Bill. I found that I got tighter regulation with the 6AH6 error amp tube over the 6AU6. I also had the problem where every time I turned it on, the regulated B+ was at a different voltage (within a 5 volt range). Once on the voltage was solid until cycling power, and then it would jump to a new stable value. Digging through some reference material, I read that the OA2, OB2 are famous for this, and that is why more precise regulators of that vintage used a 5651 reference tube. I experimented some, and the capacitor I placed across the OA2 seemed to fix the problem completely, and that regulator holds the voltage like glue now. There is a maximum value of capacitance that these VR tubes can handle before they start acting like a RC oscillator. Another issue is which side of the regulator do you pull current from to light up the VR tube? I used the output side as it seemed to provide better regulation (load and line), and lower noise output. The drawback of course is that the regulator series pass tube must give up some percentage of it's available current to support the VR tube. I had about a 2X margin of available current to needed output current, so this was a good compromise in my instance. I also played with sampling Vin and Vout at a certain ratio to feed the bias voltage to G1 of the series pass tube. There seems to be a point where the ripple rejection of the regulator goes through a peak, and the output noise nulls. Anyone ever play with that? I sure like the 6W6 as a series pass tube. I got 5 of them NOS in box for $9.99 from a Ebay auction. Look at the plate curves in triode connected configuration. They are very stout tubes for the size, and money (little demand for these so they are cheap!). Brett in your case I wonder what your Vin, and Vout voltages are, and what is the minimum Vin - Vout at Maximum load current that the circuit can accommodate before going open loop (out of regulation)? Regards, Jim Candela WD5JKO
Re: [AMRadio] Screen Regulator Circuits, 20a, etc.
Jim, the websites that you gave cannot be downloaded. Thank you. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com - Original Message - From: Jim candela [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, November 19, 2003 12:26 AM Subject: [AMRadio] Screen Regulator Circuits, 20a, etc. Hi Guys, I have been working on two HV regulator circuits in the past year where I needed +375 volts at up to 100 ma. In the first case I had 600 volts to start with, so I used a tube circuit. In the second case, all I had was about +430 which dips to about 390 at maximum output, and reduced AC line voltage, so I went solid state. My two circuits are here: Tube version: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/CE_20A_ QRO_Power_Supply.jpg Solid State version: http://pages.prodigy.net/jcandela/Sherwood_S8000/HV_REG/SS_HV_VOLTAGE_REGULA TOR.jpg The first circuit shows my complete power supply in my Central Electronics 20A QRO #2 rig. I used a pair of 7591's in the RF final to make up to 12.5 watts AM output, or about 55 watts PEP SSB output. I ended up with a 6W6 in the series regulator as it had more emission than a 5V6, even though the 6W6 only had 5 1/2 volts on the filament. This regulator is always at +374, hot, cold, month after month. The ripple from it is unmeasurable (with my equipment), and dynamic load response is excellent, although I cannot remember exactly what the results were, as that was last winter. The rest of my 20a info on the web is at: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/ The second regulator circuit is much simpler, and cheaper to build, and the performance is similar with one big exception. The regulator only needs a 15 volt delta input to output, whereas a 6W6 at zero bias triode connected needs closer to 100 volts (and that is saturated, i.e. no regulation)to pass 100 ma. The main drawback is that the solid state circuit is not adjustable. You have to get a string of zeners to add up to the desired output voltage. This is no big deal though. You can buy from Mouser (www.mouser.com) the 1 watt zeners series (1n47xx) for about 15 cents each in packs of 10, and they carry them up to 200 volts, although I prefer to go no more than 100 volts per zener for power dissipation reasons. For folk with higher input voltages, there are higher voltage fets that can pass 900 volts or more, so that isn't a big problem. The one I use is rated at 500 volts, and can be had for about one dollar. To keep the power dissipation down, add as much series R into the regulator input so that you have slightly greater than 15 volts across the regulator circuit shown at maximum load current, and minimum ac (brownout) voltage. The opto coupler in this circuit has a Darlington transistor, and the CTR (current transfer ratio) is very high, hence the excellent closed loop regulation. Reduction of power line ripple is 40 db. With only 1 ma through the zeners, the zener warm-up drift is about 1-2 volts rise. Keep in mind that this solid state regulator is still a work in progress, and still populates a proto-board on top of my Sherwood 30+30watt stereo amplifier with 4 X 7868 output tubes. I designed the circuit to be short circuit proof with the intention that if the output were shorted, the Sherwood fuse would pop before anything fried too bad. I have been way too-chicken to try this feature out. Maybe one of you brave souls can perform this test using components bought from your very own checking account! These circuits can find there way into all sorts of AM equipment...I hope that somebody tries one of these circuits and then asks me why didn't you do this _ instead Regards, Jim Candela WD5JKO ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Screen Regulator Circuits, 20a, etc.
Jim, the websites that you gave cannot be downloaded. Thank you. Dave, W3ST Secretary to the Collins Radio Association Publisher of the Collins Journal www.collinsra.com Worked for me. you have to re-join the link... or, at least know that the rest of the link, is on the next line ;-) My two circuits are here: Tube version: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/CE_20A_QRO_Power_Supply.jpg Solid State version: http://pages.prodigy.net/jcandela/Sherwood_S8000/HV_REG/SS_HV_VOLTAGE_REGULATOR.jpg The ripple from it is unmeasurable (with my equipment), and dynamic load response is excellent, although I cannot remember exactly what the results were, as that was last winter. The rest of my 20a info on the web is at: http://pages.prodigy.net/jcandela/CentralElectronics20AModifications/ If the links are still broken, then cut-n-paste the first line of the link into your browser (you can copy the whole link, but if it's split, you'll only get the first line, anyway) then past the 2nd line. Why does it do that? I really don't want to get into an OS bash-session. 73 = Best Regards, -Geoff/W5OMR
