That one transistor has a gain of 78. The antenna signal is being multiplied 78 times, so yes, it can certainly do this.
For the metal box, you could try using the can from an electrolytic capacitor. The rubber stopper in the bottom already has two holes that you can stick the leads out of.
I would be careful though, I don't know if there are harmful materials in electrolytics. If you want to try it and can't get the cap open, you can email me and I'll tell you how I do it.
If you're going to bother putting one small cap in a metal box, you might as well do it to the who circuit. If you point-to-point solder, you may be able to shove the whole thing into an electrolytic cap can as I said above. That'd be neat.
Shielding isn't going to do much for a cap, it's more important for things like coils or long component leads.
- keantoken
For the metal box, you could try using the can from an electrolytic capacitor. The rubber stopper in the bottom already has two holes that you can stick the leads out of.
I would be careful though, I don't know if there are harmful materials in electrolytics. If you want to try it and can't get the cap open, you can email me and I'll tell you how I do it.
If you're going to bother putting one small cap in a metal box, you might as well do it to the who circuit. If you point-to-point solder, you may be able to shove the whole thing into an electrolytic cap can as I said above. That'd be neat.
Shielding isn't going to do much for a cap, it's more important for things like coils or long component leads.
- keantoken
Printer
Okay, I got a free HP Laserjet 6L that was salvage because it can only feed 1 sheet at a time, and the toner is about half full. I got the rubber gloves, the medium toothbrush, the large tupperware container, and the peroxide from the grocery store. There's already a half pack of Staples basic store brand photo paper in the office.
Is there any relatively inexpensive source for copper clad boards?
Okay, I got a free HP Laserjet 6L that was salvage because it can only feed 1 sheet at a time, and the toner is about half full. I got the rubber gloves, the medium toothbrush, the large tupperware container, and the peroxide from the grocery store. There's already a half pack of Staples basic store brand photo paper in the office.
Is there any relatively inexpensive source for copper clad boards?
Re: Printer
You can get it from suppliers such as Digikey. The last time I bought from there it was ~$18.00 for a single sided 12" x 12". That was Canadian funds, so the price down there would be less.
I just received quite a bit from a seller on Ebay, but I don't want to give his name as he kinda jerked me around. It was my second order from him and, although I finally did get it, it took a long time and his communication stopped once he had my order.
Anyhow, it's a good place to look.
danielwritesbac said:
You can get it from suppliers such as Digikey. The last time I bought from there it was ~$18.00 for a single sided 12" x 12". That was Canadian funds, so the price down there would be less.
I just received quite a bit from a seller on Ebay, but I don't want to give his name as he kinda jerked me around. It was my second order from him and, although I finally did get it, it took a long time and his communication stopped once he had my order.
Anyhow, it's a good place to look.
http://www.mouser.com/Search/ProductDetail.aspx?qs=nnh8%2fA0SuH%2fpipcSqOpWTA%3d%3d
If you want to go cheap ,just one of the above will do ya
(2 FA1 boards from 1).
Just cut in half for 2 X 4.5 X 6" boards, use printed FA1
PCB template..all Done.
At $7.95 apiece (mouser) buy 2.. these boards are IMMUNE
to heat, I have tried to remove a trace with a soldering iron
with NO success (1 minute + 675f)
Specs on material...
http://www.mgchemicals.com/products/500.html
Made for that newfangled leadfree BS.
OS
If you want to go cheap ,just one of the above will do ya
(2 FA1 boards from 1).
Just cut in half for 2 X 4.5 X 6" boards, use printed FA1
PCB template..all Done.
At $7.95 apiece (mouser) buy 2.. these boards are IMMUNE
to heat, I have tried to remove a trace with a soldering iron
with NO success (1 minute + 675f)
Specs on material...
http://www.mgchemicals.com/products/500.html
Made for that newfangled leadfree BS.
OS
I'm curious on how to make a center channel that doesn't involve a resistor adder.
Here's an idea that I started up.
Using first a load, and then a capacitive adder with 0.047uF for right and 0.022 for left. . . makes a pretty version of mono sound. However, it won't work right along with a stereo pair. Maybe run that through a buffer and then do it backwards on the output side of the buffer?
Or, in other words, how to get two signals together with minimal cancellations?
Here's an idea that I started up.
Using first a load, and then a capacitive adder with 0.047uF for right and 0.022 for left. . . makes a pretty version of mono sound. However, it won't work right along with a stereo pair. Maybe run that through a buffer and then do it backwards on the output side of the buffer?
Or, in other words, how to get two signals together with minimal cancellations?
I had such fun exploring AndrewT's NFB cap options, after he expressed the figures in proportions. Somehow it goes in proportion of input cap to NFB cap is similar to the proportion of NFB cap to power supply capacitance. Well, this is just amazing. You can balance the h2/h3 bass notes of your amplifier. You can boom (cap too small) or rumble (cap too big), and you can do half of both (cap just right), which is awesome.
The guy is a genius!
The guy is a genius!
It would explode. Because of DC offset current and bias current for the input, the cap would eventually charge up, and the output DC offset would increase until it could not go any further. I don't know how much your speaker would like this.
I don't know what you are trying to gain by doing this, but you could put a resistor in parallel with the cap and this would help the DC offset (although it might still be quite bad).
If you wan to try it, I would suggest to sim first to get a stable circuit.
This might be an idea if you want to compare the "sound" of different capacitors. If you wanted to do this though, I would suggest using a very low THD chip.
- keantoken
I don't know what you are trying to gain by doing this, but you could put a resistor in parallel with the cap and this would help the DC offset (although it might still be quite bad).
If you wan to try it, I would suggest to sim first to get a stable circuit.
This might be an idea if you want to compare the "sound" of different capacitors. If you wanted to do this though, I would suggest using a very low THD chip.
- keantoken
Hi Daniel,
You really are going to have to do some studying on basic electronic principles. Here is an example where there is a very basic circuit error. I'm not trying to harp on you here, it's just that to understand what you are being told, you need some basic information.
In this case, look at where your capacitor is. Does a capacitor allow direct current to flow through it, or does a capacitor block the flow of direct current?
In your circuit, the op amp is used in a non-inverting application. The negative phase input is used for correction, in other words, it samples the output against the signal input and amplifies the difference. Imagine you put +1 VDC in the non-inverting input, what should your output be if each resistor is 1 K ohm? Now, remove the capacitor and tell me what DC voltage you would expect.
I don't think that giving you the answer will help you much. If you have to work this out, you will remember it better.
-Chris
You really are going to have to do some studying on basic electronic principles. Here is an example where there is a very basic circuit error. I'm not trying to harp on you here, it's just that to understand what you are being told, you need some basic information.
In this case, look at where your capacitor is. Does a capacitor allow direct current to flow through it, or does a capacitor block the flow of direct current?
In your circuit, the op amp is used in a non-inverting application. The negative phase input is used for correction, in other words, it samples the output against the signal input and amplifies the difference. Imagine you put +1 VDC in the non-inverting input, what should your output be if each resistor is 1 K ohm? Now, remove the capacitor and tell me what DC voltage you would expect.
I don't think that giving you the answer will help you much. If you have to work this out, you will remember it better.
-Chris
Correct, a gain factor of two.
There will be DC coming from the amplifier inputs and also DC offset at the output which will cause the cap to charge whether or not you are applying only AC input. This is usually learned after a course in basic electronics. But since I doubt you want your projects to explode some warnings can't be bad.
- keantoken
There will be DC coming from the amplifier inputs and also DC offset at the output which will cause the cap to charge whether or not you are applying only AC input. This is usually learned after a course in basic electronics. But since I doubt you want your projects to explode some warnings can't be bad.
- keantoken
How about something like on the bottom of this page?
http://ludens.cl/Electron/audioamps/AudioAmps.html
The NE5534 is designed to drive impedances at 500 ohms and up, and with a discrete output stage it can drive lower impedance phones (like 56 ohms).
For just headphones there is not need for high-power devices, you can use lower-powered ones, which will have better characteristics.
- keantoken
http://ludens.cl/Electron/audioamps/AudioAmps.html
The NE5534 is designed to drive impedances at 500 ohms and up, and with a discrete output stage it can drive lower impedance phones (like 56 ohms).
For just headphones there is not need for high-power devices, you can use lower-powered ones, which will have better characteristics.
- keantoken
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