How far we've come from 807's and 2n3866's ...
Can't grab parts off a cell phone and just solder them up into whatever you wanted. Wonder if I'd have gotten this far if I'd had to buy all my own parts!
I was a cell phone designer for about 5 years. We used 0805's and 0603's then. Some of the parts were actually useful. Now its all 0201, 0402, and uBGA. Even with the proper tools you can't recycle a BGA chip. Ditto the new chip scale packages. In my current project the voltage regulator chips are smaller than the 0603 bypass cap.
I wouldn't have. I started taking things apart before I was 10. Later I even put some of them back together. By 14 I had built several guitar amps. I did get a Weller soldering gun for my birthday, and a partially functional VOM from a neighbor. Everything else came from the local trash dump. No 807's and definitely no 2N3866's (I don't think they existed then). Tubes were plentiful as long as they were from an old TV, radio or HiFi set. My favorites were the 6BQ6 abd the 6DQ6, probably because they were so plentiful. Transistors were very rare in the trash in the early 60's. I did snag a few from old car radios.
When I was young, you could go around the neighborhood with a wheelbarrow and pick up TVs and radios at the curb for free. They were usually a good source of free parts.
I remember a transistor radio in 1964 that was advertised as having 5 transistors. Problem was two were dead and not wired into any circuit.
I remember a transistor radio in 1964 that was advertised as having 5 transistors. Problem was two were dead and not wired into any circuit.
May be there were MOSFETs wired through SMD resistors and caps?
I remember fixing some early Japanese boombox with thick film IC style resistors baked on PCB.
Just wondering how the 10lb of iron will go with 240V (more like 250V here) 50Hz mains. Will I get near 800V with a doubler (from the 235V secondary model) for a GU50 PP guitar amp or will I just get smoke? Might need a bucking transformer and go for 650/700V?
Edit: given that:
Edit: given that:
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I was considering a few of these "4.5359237 kilos of power" myself, but thought better of it...
These transformers have dual primaries, so they were designed to be used with either 110 or 220 volt power supplies, but there is no indication if this also includes operation at 50Hz. Using these transformers in Australia might be problematic - I've measured my nominal 240 volt supply from 235V ( midsummer days, air conditioning on ), to 255V ( late evening, especially weekends ). Operating a 220 volt primary at 250+ volts, especially if it was only designed for 60Hz may predispose it to self-immolation.
If you were planning to use the 110 volt primary at a ( nominal ) 240 volts, to get 800 volts DC from a doubler on the secondary, you would certainly produce plenty of acrid smoke.
You could use two transformers with the primaries wired to 220 volt operation, and the HT secondaries in series to reach the voltage you desire. With a single transformer wired for 220 volts on the primary, you could use a voltage quadrupler on the secondary, with the added bonus of power supply "sag" - often desired in a guitar amplifier.
If the postage to Australia wasn't so high, it would be worth getting a couple of these transformers to evaluate.
These transformers have dual primaries, so they were designed to be used with either 110 or 220 volt power supplies, but there is no indication if this also includes operation at 50Hz. Using these transformers in Australia might be problematic - I've measured my nominal 240 volt supply from 235V ( midsummer days, air conditioning on ), to 255V ( late evening, especially weekends ). Operating a 220 volt primary at 250+ volts, especially if it was only designed for 60Hz may predispose it to self-immolation.
If you were planning to use the 110 volt primary at a ( nominal ) 240 volts, to get 800 volts DC from a doubler on the secondary, you would certainly produce plenty of acrid smoke.
You could use two transformers with the primaries wired to 220 volt operation, and the HT secondaries in series to reach the voltage you desire. With a single transformer wired for 220 volts on the primary, you could use a voltage quadrupler on the secondary, with the added bonus of power supply "sag" - often desired in a guitar amplifier.
If the postage to Australia wasn't so high,
it would be worth getting a couple of these transformers to evaluate.Wavebourn, your "mistake" was way over my head. I don't understand the effect between 50Hz and 60Hz on a tranny primary, and smoking-bandit's reference to 110V or 92V primary depending on freq, hence the question.
Yes, Australia converted to metric in the seventies when I was in my teens, so I can do both imperial and metric, and use both most of the time, except when it comes to vehicular mpg, I only understand mpg. But 10lb sounds way better than 4.54 kg.
You hope acoustic guitar? No way, clean electric yes, but also silky smooth sustained lead notes, wild riffs and crunchy compressed power chords, of the tone that only good noble tubes can deliver...my plan is tube signal processing before the output stage, and run the output stage clean, well, unless it gets turned up to 11.
Edit: Sorry missed your post Daryl, I was thinking 2 x 110V primary in series since it's described as a dual input primary. Anyway, I bought 2 trannies and shipping was $43 for both, we will see what happens, cautiously...(the 600 to 800VDC is with a voltage doubler)
Yes, Australia converted to metric in the seventies when I was in my teens, so I can do both imperial and metric, and use both most of the time, except when it comes to vehicular mpg, I only understand mpg. But 10lb sounds way better than 4.54 kg.
You hope acoustic guitar? No way, clean electric yes, but also silky smooth sustained lead notes, wild riffs and crunchy compressed power chords, of the tone that only good noble tubes can deliver...my plan is tube signal processing before the output stage, and run the output stage clean, well, unless it gets turned up to 11.
Edit: Sorry missed your post Daryl, I was thinking 2 x 110V primary in series since it's described as a dual input primary. Anyway, I bought 2 trannies and shipping was $43 for both, we will see what happens, cautiously...(the 600 to 800VDC is with a voltage doubler)
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I've got one of each kind on the way (235v and 170v). My hope is to use the 170v version with a full wave solid state bridge and get about 220VDC for running a pair of 6BM8. The tubes will draw about 70 mA and the heaters need less than 1.6 A for both tubes. So what will I be pulling from the PT - about 25 watts? At this level, will I care if I'm running the primary at a higher voltage than designed? I don't think it will run hot, but I don't want it noisy (mechanically or magnetically). I don't want the heater voltages running way over spec either, shortening the life of my tubes. Should I connect the unused 6.x volt secondary in series with the primary to increase the primary voltage rating?
I just tried the boat anchor at 140V off the variac and amazingly it doesn't hum.
Let me review my test methods on the magnetizing current. I measured a Hammond and a MagneteK-Triad xfmr of similar size using the variac on the primaries and a current probe displaying idle primary current on a scope. Both of those were rated at 115 VAC primaries. Both behaved exactly the same. So I did the same with the Ebay unit and adjusted to get the same amplitude of magnetizing current and same wave shape. (As you increase the variac voltage on any of these xfmrs, the magnetizing current increases and then develops a spike which starts to increase quite rapidly usually around 140V.) I got 110 VAC instead of 115 VAC for the same current amplitude and shape. Hence the declaration of a 110V primary.
But, this is no hard and fast rule. Some transformers are designed for higher magnetizing current on purpose, usually for getting a lump more power thru than the nominal rating given for a core size. This is because less copper (fewer turns, but now bigger wire, fills the bobbin) means less I2R loss, so more power thru-put. This comes at the expense of higher idle power loss from the higher magnetizing current. (Which causes higher core loss, and some small additional copper loss too.)
I have just such an example xfmr too. It was made by Hammond and sold surplus by MECI a few years back. It is built using a nominal 300 Watt core. (exact same size as the Edcor CXPP100 OTs). But its rated at 500 Watts!! The clue is the thermal rise rating that is labelled on it: 80 degrees C!!! You could cook eggs on it. Its made with special high temp insulation. And if I test it on the variac and scope it has exactly the same magnetizing current behavior as the Ebay boat anchor. I would rate it a 110 V primary with respect to the "normal" transformers I have around. But it says right on the label that its got a 120 VAC primary. They used less turns to hold down copper losses (at high power) at the expense of higher magnetizing losses (mainly a low power idle concern).
The Ebay xfmrs appear to be vacuum dipped in Epoxy (feel like a chunk of lead). So this may damp down mechanical noise. And would probably improve heat transfer from the windings to the surface. So these may be rather higher power xfmrs than the expected 200 Watt core rating too. So it may all boil down to how you want to operate these. High power as is, or good idle efficiency with the 6.3 VAC buck winding inserted.
Let me review my test methods on the magnetizing current. I measured a Hammond and a MagneteK-Triad xfmr of similar size using the variac on the primaries and a current probe displaying idle primary current on a scope. Both of those were rated at 115 VAC primaries. Both behaved exactly the same. So I did the same with the Ebay unit and adjusted to get the same amplitude of magnetizing current and same wave shape. (As you increase the variac voltage on any of these xfmrs, the magnetizing current increases and then develops a spike which starts to increase quite rapidly usually around 140V.) I got 110 VAC instead of 115 VAC for the same current amplitude and shape. Hence the declaration of a 110V primary.
But, this is no hard and fast rule. Some transformers are designed for higher magnetizing current on purpose, usually for getting a lump more power thru than the nominal rating given for a core size. This is because less copper (fewer turns, but now bigger wire, fills the bobbin) means less I2R loss, so more power thru-put. This comes at the expense of higher idle power loss from the higher magnetizing current. (Which causes higher core loss, and some small additional copper loss too.)
I have just such an example xfmr too. It was made by Hammond and sold surplus by MECI a few years back. It is built using a nominal 300 Watt core. (exact same size as the Edcor CXPP100 OTs). But its rated at 500 Watts!! The clue is the thermal rise rating that is labelled on it: 80 degrees C!!! You could cook eggs on it. Its made with special high temp insulation. And if I test it on the variac and scope it has exactly the same magnetizing current behavior as the Ebay boat anchor. I would rate it a 110 V primary with respect to the "normal" transformers I have around. But it says right on the label that its got a 120 VAC primary. They used less turns to hold down copper losses (at high power) at the expense of higher magnetizing losses (mainly a low power idle concern).
The Ebay xfmrs appear to be vacuum dipped in Epoxy (feel like a chunk of lead). So this may damp down mechanical noise. And would probably improve heat transfer from the windings to the surface. So these may be rather higher power xfmrs than the expected 200 Watt core rating too. So it may all boil down to how you want to operate these. High power as is, or good idle efficiency with the 6.3 VAC buck winding inserted.
Another factor would be filament voltages, with 120 VAC straight on the primary you get 6.85 VAC open circuit, and with the yellow bucking winding inserted and 120 VAC you get 6.49 VAC open circuit filament. (of course loading will drop these filament voltages, so your filament load, and B+ load to a lesser extent, may dictate the desired hook-up)
Forgot to mention that the xfmrs I used for comparison in the magnetizing current test were both rated 115 VAC primaries at both 50 or 60 Hz. So that would mean that the Ebay xmfr should handle 50 Hz too. (well, at least with the 110 VAC equivalent rating) Seeing as it even handles 140 VAC 60 Hz without humming noticeably, it may work OK on 120 VAC 50 Hz too, just get rather warm I guess. ( well, 5/6 of 140 => 116.6 V)
I made a liar out of myself and picked up a couple of the high voltge editions of this transformer last night. My line voltage is ~ 120V, as I'm first in line at the distribution transformer, so I'll probably have to use one of the filament windings for bucking. These wii still be lightweights compared to my monster Baldwin transformers. The filament windings on them look like they belong on a welder...
Well, lets see, working backwards from the 110 VAC at 50 Hz equivalent rating, would give a 110*6/5=>132 VAC at 60 Hz rating. So these should be fine on straight 120 VAC 60 Hz (no filament winding case). Just don't have the same overvoltage margin a 120 VAC rating would give.
Net result being, these run a bit hotter than the usual 700 CM rated xfmrs (without the filament winding added). (700 Circular Mill rating being the usual current density rating for copper wire in "normal" xfmrs)
Net result being, these run a bit hotter than the usual 700 CM rated xfmrs (without the filament winding added). (700 Circular Mill rating being the usual current density rating for copper wire in "normal" xfmrs)
When the power company changed our line distribution transformer (mine used to be about 5 houses down), my line voltage jumped up to about 125V or so. They have since toned it down a little. I do tend to get all sorts of glitches and such, being first in line. Until I installled a UPS/surge protector on my computer, I was getting a distressing number of spontaneous "blue screens of death". The surge proector apears to have fixed that.
I remember back in the 60's when everyone was installing central airconditioning. Wasn't too long and the utility xfmr went up in flames a couple of houses down. They put in a much bigger one and the voltage went up, then they put more xfmrs in a few years later (fewer houses per). I hear that a lot of the latest utility pole piggies are amorphous core now. Wouldn't mind getting one of those cores. Big, big OT!
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