[MRCA] VN-era speakers

[Rob Flory]

The LM-380 idea is interesting.  If I decide to invoke "It's better to have
it and not need it, than to need it and not have it"   I might do that.
"It" being lots of audio output.

Check http://www.youtube.com/watch?v=rU-bqz0xR98   to see TBX driving a
speaker outdoors, with the speaker obscured by the set, at a distance of 10
feet or so.  Another video of QSO with KD3ZK showing ample audio.
Unfortunately I think I sold that speaker, into which I had built a 600-ohm
to low impedance transformer.

I'm not trying to blast a crowd, just a half dozen people around the
operating table.

RF


On Thu, Aug 22, 2013 at 9:00 AM, Ray Fantini <RAFANTINI at salisbury.edu>wrote:

> Don’t matter what speaker you use the TBX was never designed for driving
> much beyond a set of headphones. If you’re going to do the large speaker
> and have to use something that looks appropriate why don’t you get a 166
> and stuff a LM-380 in it? The LM will develop about two watts of audio and
> will only require about three external components like an output capacitor
> and DC bypass on the +12 volt input and give you 2 watts of low impedance
> audio. May want to add a resistor to serve as a termination to the TBX
> because the LM has a high input impedance and if you want to be fancy you
> can install a pot with a on off switch in the speaker and an internal nine
> volt battery and the whole thing will be self-contained. Imagine if you
> wanted to do it old school you can always build up something with a 6C4 and
> a 6AQ5 or for you octal people a 6J5 and a 6V6 for the same two watts but I
> have used the LM-380 on a bunch of projects and you can buy them all day
> long on EBay for a couple bucks and it runs from a nine volt battery, try
> doing that with tubes.****
>
> ** **
>
> Ray F****
>
> ** **
>
> *From:* mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net]
> *On Behalf Of *Rob Flory
> *Sent:* Thursday, August 22, 2013 7:33 AM
> *To:* mrca
> *Subject:* [MRCA] VN-era speakers****
>
> ** **
>
> Hi All,****
>
> Thanks for all the responses.  It turns out I have a LS-166/u.  I was
> looking for a nomenclature tag in the dark without my glasses, but when the
> sun came up a little higher I saw the engraved markings.****
>
> ** **
>
> I think it will serve the purpose, but I am going to look into some other
> options like the Radio Shack amplified speaker.****
>
> ** **
>
> RF****
>
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