Common speaker for vario and radio

Electronics guru's,

Can I use 1 speaker for both by radio (Becker 3201) and vario (LX160).
Both call for a 4ohm speaker.

Would connecting both to one speaker still work ?
Would it be too quiet ?
Any chance for damage to the radio or vario ?

Thanks
Todd Smith
3S

Can I use 1 speaker for both by radio (Becker 3201) and vario (LX160).
Both call for a 4ohm speaker.

Strictly speaking no.

Would connecting both to one speaker still work ?

No

Would it be too quiet ?

That's not the problem

Any chance for damage to the radio or vario ?

Very much so.

There are a couple of options

1 - A 2 channel mixer and reamplifier driving one speaker.

2 - Feed the vario audio ( suitably attenuated ) into the audio /
intercom input of the radio. The radio amplifier then drives the speaker
with the vario audio until the radio breaks squelch and you hear the
radio signal.

3 - Simplest solution ........... Two speakers.

Ian

NO........
not unless you want to replace the Becker radio and Variometer....and maybe
the speaker too )
tim

--
Wings & Wheels
www.wingsandwheels.com

"toad" wrote in message
ups.com...
Electronics guru's,

Can I use 1 speaker for both by radio (Becker 3201) and vario (LX160).
Both call for a 4ohm speaker.

Would connecting both to one speaker still work ?
Would it be too quiet ?
Any chance for damage to the radio or vario ?

Thanks
Todd Smith
3S

A solid resounding NO it is!

I won't do it. In fact I alleady have 2 speakers,
I was just trying to reduce the amount of stuff in the glider.

Thanks a bunch
Todd

Todd,

Glad you aksed the question. I suspected that the answer was no, but
since I only get audio from the speaker connected to my LX5000 on every
other flight, I was wondering whether a one-speaker solution was
feasible.

(When the LX5000 fails to give me audio I just crank up the B-40, but
it has a problem too ... if a gust or a thermal pushes it over 10
knots, the audio "latches" onto that max tone and stays there until
another max gust frees it somehow, or I cycle it off and back on.)

ted/2NO
chandler az

toad wrote:
Electronics guru's,

Can I use 1 speaker for both by radio (Becker 3201) and vario
(LX160).
Both call for a 4ohm speaker.

Would connecting both to one speaker still work ?
Would it be too quiet ?
Any chance for damage to the radio or vario ?

Thanks
Todd Smith
3S

wrote:
Todd,

Glad you aksed the question. I suspected that the answer was no, but
since I only get audio from the speaker connected to my LX5000 on every
other flight, I was wondering whether a one-speaker solution was
feasible.

(When the LX5000 fails to give me audio I just crank up the B-40, but
it has a problem too ... if a gust or a thermal pushes it over 10
knots, the audio "latches" onto that max tone and stays there until
another max gust frees it somehow, or I cycle it off and back on.)

ted/2NO
chandler az


Stay away from those 10 knot thermals!

The Becker 4201 transceiver has an "auxiliary" audio input, where you can
bring in an external audio signal. I do not have a manual for the 3201 and
do not know if it has the same feature. The 4201 specifies the input at
600 ohm of 1-8 volts, and the level is adjusted with the 4201 in "service"
mode.

Normally, speaker outputs are specified at 4 ohms. The mismatch between the
Becker and the audio output is not a problem - as long as you can generate
enough voltage to develop at least 1 volt. This could be done by putting a
16 ohm resistor across the vario. If you can generate 62 mw of audio across
16 ohms, yu can develop 1 volt of audio.

If enough drive voltage is not developed, you can use a 4 ohm to 600
transformer to step up the voltage. I would put a 1000 ohm load resistor
across the secondary, just to insure some load.

But, the 3201 may not have anything like this.

If the 3201 does not have an auxiliary input, you can still utilize 1
speaker by building a small universal audio amplifier, with various inputs
that are joined (and properly isolated). Some airplanes use just such an
audio panel. An LM-386, with multiple inputs could be used. I think Radio
Shack has a book of simple circuits that has just such a schematic.

If none of these options are available, a very small speaker can be used for
the vario. Since it is a high audio frequency, tiny speakers will work
fine. Rip one out of an old desktop computer.

Colin N12HS

COLIN LAMB wrote:


If none of these options are available, a very small speaker can be used for
the vario. Since it is a high audio frequency, tiny speakers will work
fine. Rip one out of an old desktop computer.

A pilot truly determined to eliminate the vario speaker should also
consider buying a vario with an internal speaker. A simple option, but
more expensive!

What I'd like to "eliminate":

* the EDS oxygen controller/switch box - I wish it had a small controls
panel (switches and LEDs) I could mount on the instrument panel, with
the main box stuck in back with the oxygen bottle
* the headphone controls/battery box - I wish it was all contained in
the headphones (headphones, you ask? I fly a motorglider)
* the outside air temperature meter - the OAT is also available on my
302 vario, but it's about 10 button presses to get to it (some day I'll
persuade Team SeeYou to make it a Navbox readout on SeeYou Mobile!)

These changes would reduce the "clutter" a bit.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Eric Greenwell wrote:
* the outside air temperature meter - the OAT is also available on my
302 vario, but it's about 10 button presses to get to it (some day I'll
persuade Team SeeYou to make it a Navbox readout on SeeYou Mobile!)

The OAT meter is required for certification of German gliders equipped
with water ballast, and is therefore required under the US type
certificate. So, it can't be eliminated, unfortunately...

Marc

Earlier, Marc Ramsey wrote:

The OAT meter is required for
certification of German gliders
equipped with water ballast...

[slight thread hijack]

Has anybody on this forum ever, ever looked at the OAT guage and said,
hey, it's too cold here, I'd better dump water or descend?

Given how effective composite sandwich construction can be as an
insulator, it seems to me that what they _should_ be requiring is a
ballast temperature guage...

Bob K.
http://www.hpaircraft.com