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SM2GXN
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Posts posted by SM2GXN
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EHT= high tension.
Some of these horizontal output transistors (HOT) have damper diode built in between collector and emitter that might be the reason why you get .6V, try to swap testleads and if you get same .6 volts the transistor is probably shorted, measure resistance across collector/emitter instead of diode.
If the HOT is shorted chance is that the step down converter could be faulty as well, if the coil is shorted you might have to wind one by yourself these are usually not an easy to find spare part ??? -
Hi ALi!
Hopefully this is what you are looking for ;) -
Don't think it is a good idea to degauss a crt with a loudspeaker magnet it will get even worse and if you place a magnet to close to the front of the crt you can actually damage the crt and you are looking for real trouble. Degaussing is usually done by running ac current throgh a coil at the front of the crt just about in the same way as the degauss circuit in a crt monitor or tv works.
Your ghosting could depend up on several things, bad vga cable, drivers?
If the colours doesn't seem to be right degauss is probably the solution for your problem.
Check this link also: http://wiki.ehow.com/Degauss-a-Computer-Monitor
Bad focus can be adjusted to a certain limit but if the crt is bad it can't. -
Yes you are right, 5 volts is nominal, if more than 100mA is to be drawn from the USB the device should be powered from an auxilary supply but some USB,s will deliver up to 500mA. Don't know if the USB has any type of currrent limiter so one should be careful.
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Just an add to windoze killa excellent post, what brand and model number?
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Here's some good reading about GTO,s
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Here's a link that might be of interest but it's the lazy way of calculating ;D
http://web.telia.com/~u85920178/blocks/osc7m00.htm -
Happy birthday Steven!
Hope you will have a nice birthday party, watch out for bad hangover ::) -
Audioguru you are probably right, there is no trip or holdtime to adjust but wikipedia was right about the vox ;D
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Hey Staigen did you drop a screwdriver or a metallic snuf box on your mother board?
POOOF!!!! ;D -
Hi logan_dslasher!
You are perfectly right, couldn't be said better ;D -
By the way audioguru, have ever tried to simulate an AM circuit in switchercad?
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Hi audioguru!
I think it will create AM and two sidebands if you inject a sine wave into the emitter,
if I don't remember wrong just about same configuration is used in RF but as collector load a tuned L/C circuit.
What do you think audioguru? :) -
When you say 85dB you probably mean the loudspeakers sensitivity which is measured by feeding the loudspeaker with a voltage that produce 1W at its impedance and a microphone at a distance of one meter from the loudspeaker.
To produce 1W in a 8ohm speaker you need 2,83 volts RMS, same voltage into a 4ohm speaker will produce 2W, since we are dealing with power the measured value in dB/watts has to be lowered by 3 db=half to get it right or decrease the voltage to 2 volts RMS.
I don't think there is any formula that can tell you how much the loudspeaker can withstand in watts but you can measure its sensitivity, think the only way is to go by the manufacturers specifikation.
Hopefully this will sheed some ligh to your question -
Well Ante, if Staigen and I lived closer we would stop by and bring all necessary tools for a successful evening ;D
Cheers!! -
Hi ZAP101!
Ill do my best...
BD139 TO220= NTE375
BD139 TO126= NTE184
MJ11016= NTE2349
MJ11015= NTE2350
BC546= NTE123AP
BC556= NTE159
BC559= NTE159
BC549=NTE123AP
BD139= NTE184
BD140= NTE185
TIP35C= NTE392= (TIP35A)
TIP36C= NTE393= (TIP35A)
;) -
Sorry I forgot to place the link in my post, there's nothing wrong with your opera Godfather
Thanks audioguru ;) -
Hi Godfather!
You can download it directly from LT website, here's the link to the download page just click on LTSpice/SwitcherCAD III -
Hi akolo georges!
In eagle:
File/export/image put name on the file you want to export, location and choose format bmp, png.... press OK and you are done ;) -
Hi sssaaa!
As I said for listening it is not that critical, those formulas take conductor thickness as well as speed of the radio wave into acount. One can say that as the antenna element gets thicker the total length decreases and the antenna will cover a greater bandwith. If the antenna is to be used as transmitting antenna you will have to tune the antenna by cutting to proper length and resonance.
468/Mhz= length in feet is a formula for guys living in US ;D -
Hi logan_dslasher!
Thanks, well if I had a software that could export tp PDF I would copy every single chapter and transfer it to PDF. Some of the books they got are downloadable but not those I mentioned in my post ;D -
Hi sssaaa!
Did you read our posts?
windoze killa and I wrote about how to calculate the length.
The formula is in there, just calculate the antenna at center 84Mhz it will do just fine for listening no need for two antennas, 150/84=Half wave dipole length in meters, cut the length in two pieces solder a 75 ohm coax or a twin lead to the two ends depending on the transmission hang the antenna horizontal or vertical.
If you want two antennas just use the formula above and insert the frequency of interest. -
Hi!
Found these two excellent books on the web, these are for newbies as well as for pro,s
First one handle radio receivers:
http://www.mikroelektronika.co.yu/english/product/books/rrbook/rrbook.htm
The second one take care of electronic components:
http://www.mikroelektronika.co.yu/english/product/books/keu/00.htm
If you like these books let them know by email, they have done an excellent job :) -
Check this link, it might be what you are asking for.
http://www.epanorama.net/circuits/microphone_powering.html
CRT monitor
in Electronics chit chat
Posted
I don't even know if your monitor has step down converter, a schematic would be a great help, the step down converter supply collector voltage for the HOT, if this converter doesn't work the voltage to the HOT is usually to high and will result in destruction.
Use high res scale I think you would get not less than 1Mohm if you get low reading both ways swap transistor.
Check the model number otherwise all advises will just be a guess ;D