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Old 19th Nov 2020, 1:03 pm   #1
Pete_kaye
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Default What is it?

It runs from 2 x 9V batteries and has a note inside about setting the zero and leaving it be . Obviously , home made . Will it be of any use in radios?
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Old 19th Nov 2020, 1:33 pm   #2
Chrispy57
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Default Re: What is it?

On the face of it I assume that it is a home-brew DC Amplifier using op-amp(s) - unlikely to be of any use in radio work really. May be a useful source of parts for future?

Cheers
Chris
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Old 19th Nov 2020, 1:35 pm   #3
Pete_kaye
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Default Re: What is it?

Yes .I think I will offer it here.
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Old 20th Nov 2020, 9:37 am   #4
trh01uk
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Default Re: What is it?

I'm afraid with the very scanty information on the front panel, all we can say is that it is some kind of DC amplifier, with a set zero control, and possibly a gain control - though I am only guessing that is the meaning of "Range"!

There is no info on what power it needs, what gain it offers, what bandwidth it has (Yes, its a DC amp, but it will also have some AC bandwidth), and what input impedance it has and what load it will drive.

You might open it up and take some photos of the insides, so we can see what kind of circuitry it has. If there are any ICs in there, make sure we can see the part number.

Otherwise I'm afraid this has little value to anyone. You might even struggle to give it away for the cost of the postage! Sorry!

Richard
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Old 24th Nov 2020, 3:49 pm   #5
Pete_kaye
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Default Re: What is it?

Here Are some photos.
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Old 24th Nov 2020, 4:03 pm   #6
duncanlowe
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Default Re: What is it?

The amplifier is a fairly standard operational amplifier, or opamp, called a 741.

Essentially you put a small voltage in, and it amplifies it as in makes it bigger. Do a search for 741 and it should make sense.

What I don't understand is how come there are only two connections. I'd expect at least three, input, output and ground.
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Old 24th Nov 2020, 4:07 pm   #7
Pete_kaye
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Default Re: What is it?

The outputs are on the other face, not in photo.
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Old 24th Nov 2020, 8:06 pm   #8
trh01uk
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Default Re: What is it?

Pete

to return to your original question, now we know better what it is that you have, I can't think of any specific use for it in radio work. Someone doing audio work with an insensitive scope might just find it useful.

If you want to offer on the "Offered" section of this forum, you could try it at a fiver, and see what interest there is. Don't forget postage isn't cheap though!

Richard
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Old 25th Nov 2020, 1:21 pm   #9
Pete_kaye
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Default Re: What is it?

Thanks Richard.
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