Common speaker for vario and radio

[toad]

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

[Ian Molesworth]

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

[Tim Mara]

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

[toad]

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

[[email protected]]

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

[Greg Arnold]

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!

[COLIN LAMB]

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

[Eric Greenwell]

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

[Marc Ramsey]

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

[Bob Kuykendall]

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

[Marc Ramsey]

Bob Kuykendall wrote:
> 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?

Yes.

> 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...

The main problem is the tail tank, which is a relatively small volume of
water, isn't all that well insulated, and will freeze in a matter of a
few hours if the outside temperature is low enough. In at least one
case, the expansion of the ice caused the vertical fin to split open...

Marc

[Bob Salvo]

Then put the ballast temperature sensor in the tail tank, which should also
be insulated to help prevent heat loss.

Bob

"Marc Ramsey" > wrote in message
.. .
> Bob Kuykendall wrote:
> > 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?
>
> Yes.
>
> > 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...
>
> The main problem is the tail tank, which is a relatively small volume of
> water, isn't all that well insulated, and will freeze in a matter of a
> few hours if the outside temperature is low enough. In at least one
> case, the expansion of the ice caused the vertical fin to split open...
>
> Marc

[Bill Daniels]

"Bob Kuykendall" > wrote in message
ups.com...
> 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

I did exactly that.

I contacted unexpected wave from thermal lift at the Alamogordo Soaring
Fiesta last June. To climb in wave, I descended below the freezing level
and allowed the skin of the glider to warm and then dumped ballast. When
the water was gone, I found the wave again and made it up to 22,000 feet.

I knew there would be some water left in the tanks but not enough to be a
concern.

Alamogordo rocks!

Bill Daniels

[Bob Korves]

Warning, long post!

Freezing of the ballast tanks is not the only problem.

I am "closely familiar" with three separate water ballast incidents.

The first was in a 2 seat Schempp-Hirth glider with the type of tail ballast
tank that has holes that one tapes over to determine the ballast quantity.
Half way into a 300K out and return flight and after some straight cruising
at altitudes of 16-18K feet (4500-5500 meters) it was noticed that the
rudder would not move. Moderate pressure on front, back and both sets of
rudder pedals would not free the rudder in either direction. It was still
possible to soar the glider toward home and it was possible to thermal,
though without the use of the rudder it was not pretty. On final glide at
about 10K feet (3000 meters) the rudder came loose and the pilots made an
uneventful landing. Inspection of the rudder area showed that the tape,
which had been on the glider for some time, had pooched out and started
leaking from one of the lower holes. It appeared that the water had run
into the rudder counterweight slot and had frozen there. Landing without
rudder could have been ugly.

The second incident was on the same Schempp-Hirth 2 seat glider. The
ballast drains are some distance from the wing roots and draining is visible
to the front pilot while dumping the ballast. The glider was again being
flown long distances at high altitudes above the freezing level. The front
pilot noticed that there was a fin of ice extending below and aft of the
drain opening about 2" wide, 6" high (50 X 150mm) and extending to the
trailing edge of the wing. This appeared to not cause much degradation to
the handling or performance of the glider, and the fin fell off upon
descending through the freezing level. The valve was obviously leaking, not
enough Chap Stick on the valve!

The third occurrence was in a PIK-20D sailplane which had taken off with a
known slow drip coming out of the wing at the back of the right side wing to
fuselage tape. After a period of cruising at high altitude a thermal was
entered, a pull-up was initiated followed by increasing the flaps to the
thermalling setting. The stick was pushed to the right side by the flap
position change and an un-commanded and brisk aileron roll was started to
the opposite side from the left turn that was desired. The flaps were
promptly put back in the cruise setting and the glider was able to be
ruddered into the thermal from a right turn. It was determined that the
flaperon on the right side was stuck in position. Some judicious wiggling
of the stick was able to free the stuck flaperon and the flight continued
with regular wiggles of the ailerons. Conditions were very good on the
return and the speed on final glide was increased to 130 knots when BANG,
BANG, BANG was heard which was followed by a gentle pull up to a slower
speed. The noise soon went away and the glider was slowly speeded up again
which was OK. After landing it was noticed that the tape on the bottom of
the right wing was separated from the surfaces from the front of the flap
forward to half chord and was stretched to 12" (30 cm) behind the wing. The
problem was probably caused by a buildup of ice on the flaperon flow fence
below the wing which froze the flaperon in position and then, later, on
final glide, broke off and, stuck to the tape, was beating against the
fuselage like a mace.

Yes, the pilot involved in all these incidents knew about dumping ballast
passing the freezing level but figured that it would take a long time to
freeze the water in the tanks, which is true. Some guys just don't learn
with experience that there might be other problems. (-;

Y'all be careful out there...
-Bob Korves




"Bob Salvo" > wrote in message
...
> Then put the ballast temperature sensor in the tail tank, which should
also
> be insulated to help prevent heat loss.
>
> Bob
>
> "Marc Ramsey" > wrote in message
> .. .
> > Bob Kuykendall wrote:
> > > 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?
> >
> > Yes.
> >
> > > 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...
> >
> > The main problem is the tail tank, which is a relatively small volume of
> > water, isn't all that well insulated, and will freeze in a matter of a
> > few hours if the outside temperature is low enough. In at least one
> > case, the expansion of the ice caused the vertical fin to split open...
> >
> > Marc
>
>

[Eric Greenwell]

Bob Salvo wrote:

> Then put the ballast temperature sensor in the tail tank, which should also
> be insulated to help prevent heat loss.

Even better would be to put the wing ballast in a location that doesn't
require tail ballast to compensate for it.

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

Eric Greenwell
Washington State
USA

[COLIN LAMB]

WOW! I did not realize I needed de-icing boots on a sailplane.

Colin N12HS