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Mohican question, capacitors.
01-21-2016, 05:16 PM
Post: #14
RE: Oscilliscope question
Nice radio!

Finding high impedance speaker drivers with that sizing is not an easy task anymore.
Good hunting!

The impedance here is that critical for this application.
35ohm with 20% tolerance is not an issue on that output circuit.

By the way, make sure the output coupling capacitor is is good condition BEFORE connecting a new speaker (at least it must not be in short circuit on DC - a common multi-meter in DC resistance can test for this - or else the speaker will most probably burn very fast, considering its low power handling).

Meanwhile, if you don't mind a little diy Smile , this is what I would do:

Get a set of four common easy to find small low power (0.5Watt or less) 32ohm speaker drivers.
These are very common on 4cm diameter sizes. See here and here or here.

Create two pairs of two speakers in series and connect them in parallel for a total of 32 Ohm.

Make a wood plate buffer with 4 x holes for the speaker drivers.
You will end up with a bigger sound than what it seems possible from such small drivers.
However the audio bandwidth will be somewhat limited specially on the bass but I guess that is not an issue on these radio applications.

See the draft picture for electrical details.


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Jose Mesquita
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Messages In This Thread
RE: Oscilliscope question - Garth Wilson - 01-21-2016, 05:49 AM
RE: Oscilliscope question - walter b - 01-21-2016, 09:55 AM
RE: Oscilliscope question - jebem - 01-21-2016 05:16 PM
RE: Oscilliscope question - rprosperi - 01-21-2016, 11:51 PM
RE: Oscilliscope question - Steve Simpkin - 01-22-2016, 04:15 AM
RE: Oscilliscope question - jebem - 01-21-2016, 06:27 PM
RE: Oscilliscope question - Garth Wilson - 01-22-2016, 02:10 AM
RE: Oscilliscope question - vk6ti - 01-22-2016, 09:30 AM
RE: Oscilliscope question - jebem - 01-22-2016, 10:29 AM
RE: Oscilliscope question - jebem - 01-22-2016, 08:46 PM
RE: Mohican question, capacitors. - vk6ti - 01-23-2016, 12:14 AM
RE: Mohican question, capacitors. - jebem - 01-23-2016, 07:55 AM
RE: Mohican question, capacitors. - jebem - 01-23-2016, 07:53 PM



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