West Mountain Radio PWRspkr 15W User manual

www.westmountainradio.com
1020 Spring City Drive
Waukesha, WI 53186
262-522-6503
[email protected]
©2012 West Mountain Radio, All rights reserved. All trademarks are
the property of their respective owners.
PWRspkr 15W

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West Mountain Radio Operating Manual
Thank you for choosing the PWRspkr 15W. You will nd that this
LOUD loudspeaker improves your communications especially in noisy
environments.
The PWRspkr 15W is a loudspeaker containing a 15-watt RMS linear power
amplier. The amplier uses an active bandpass lter that limits the audio to
a 300Hz to 3.2kHz bandwidth. This makes it ideal for voice communications.
The PWRspkr 15W comes with two six foot cables. The audio cable plugs
into the 3.5 mm speaker or headphone output of a radio. The powerpole
connector plugs into any 12 volt power source.
The volume control allows for setting the audio level for comfortable listening.
The PWRspkr 15W has plenty of gain. It can get very loud and this is useful
in a noisy vehicle.
The PWRspkr 15W is ideal for mobile radio stations for hams, CB radio,
commercial radio, emergency radio, ambulances, police vehicles, and small
public address systems.
Installation
The PWRspkr 15W should be installed in a weather-protected area. If it is for
communication purposes place it near the operator. The cables are six feet
long.
Remove the bracket from the speaker housing. Then secure the bracket to
any at surface using the supplied screws or other hardware. Re-mount the
loudspeaker, aim it, and securely tighten the knurled nuts.
The audio cable has a stereo 3.5 mm plug. The tip is for the audio, the ring
is not connected, and the sleeve is common. This connector is for mono
audio. When plugged into a stereo source the PWRspkr 15W will play the left
channel audio only; it will not short out the right channel. A stereo extension
cable may be added if needed.
The power cable is tted with red and black Powerpole connectors. It should
be plugged into a fused source, such as a RIGrunner power strip connected
to 12 volts. Use a 5 Amp fuse. The Red is plus 12 volts, and Black is common.
An extension cable may be used if needed.
(Powerpole® is a registered trademark of Anderson Power Products)

3
West Mountain Radio Operating Manual
Operation
Turn on the PWRspkr 15W using the Power/Volume knob . The green LED
will light. Adjust the volume control for the intended listening level.
Note: The radio also has a volume control and it must be turned up for the
PWRspkr 15W to work.
It is possible to use either the radio or PWRspkr 15 W volume as the master.
It is recommended to set one volume control half way up. Then the adjustable
volume control can go both above and below the nominal listening level.
Circuit Description
The PWRspkr uses a 4-inch loudspeaker driven with a 15-watt RMS power
amplier.
The power amplier is a class–AB linear amplier connected as a bridge-
tied-load (BTL). This allows the amplier to produce 15 watts RMS into 4
ohms audio when powered by 13.8 volts without using an output transformer.
Note that both leads of the loudspeaker driver are “hot” and neither can be
grounded.
The power amplier integrated circuit has internal protection for overheating
and a short-circuited loudspeaker.
Input audio is applied through a resistive dividing network and coupled to the
pre-amplier via an isolating transformer. The input resistance is 100 ohms.
There are lter capacitors to remove any rf pickup from the audio line.
The internal pre-amplier contains an active 300 Hz to 3.2kHz band–pass
lter. Note that the lter permits only “intelligence-energy” to reach the
loudspeaker driver. The “lows” and the “highs” are attenuated and not applied
to the loudspeaker. This is why the sound level can be very high without
damaging the loudspeaker from over excursion or excessive heat.
The loudspeaker sound pressure level (SPL) is 102.5 dB typical at 1 meter
before electronic clipping.
DC power is applied through a ferrite inductor and shunt capacitor to remove
any RF on the power leads. Large electrolytic capacitors further lter the
internal DC for any noise or ripple appearing on the DC power line.

Specications
Dimensions 5.5 x 4.3 x 2.5 in.
6.5 x 4.7 x 2.7 in. when mounted
Power Requirements 9 to 16 VDC
Current: 2A max w/ 13.8V supply
Quiescent current 90mA typical
Sensitivity 0.83 VRMS produces full output into
4 ohms (1kHz signal, 13.8V supply)
Loudspeaker Driver 4 in. treated paper cone
4 ohm impedance
Rated Power: 20 watts
Power Amplier -
Integrated Circuit
Class AB Linear BTL (bridged-tied-load) circuit
15 watts RMS audio output into 4 ohms when powered
by 13.8V supply
Short circuit protected by shut down
Over-heat protected by shut down
Heat sink is the two PCB ground planes
Pre-Amplier Active four stage lter with gain
Frequency response is at 300 to 3.2kHz
18 dB/octave high-pass at 300Hz (-3 dB)
18 dB/octave low-pass at 3.2kHz (-3 dB)
PWRspkr 15W Warranty
PWRspkr 15W is warranted against failure due to defects in workmanship or
materials for one year after the date of purchase from West Mountain Radio.
Warranty does not cover damage caused by abuse, accident, misuse, improper
or abnormal usage, failure to follow instructions, improper installation, alteration,
lightning, or other incidence of excessive voltage or current. If failure occurs within
this period, return the PWRspkr 15W or accessory to West Mountain Radio at
your shipping expense. The device or accessory will be repaired or replaced, at
our option, without charge, and returned to you at our shipping expense. Repaired
or replaced items are warranted for the remainder of the original warranty period.
You will be charged for repair or replacement of the PWRspkr 15W or accessory
made after the expiration of the warranty period.
West Mountain Radio shall have no liability or responsibility to customer or
any other person or entity with respect to any liability, loss, or damage caused
directly or indirectly by use or performance of the products or arising out of any
breach of this warranty, including, but not limited to, any damages resulting from
inconvenience, loss of time, data, property, revenue, or profit, or any indirect, special
incidental, or consequential damages, even if West Mountain Radio has been advised
of such damages.
Except as provided herein, West Mountain Radio makes no express warranties
and any implied warranties, including fitness for a particular purpose, are limited
in duration to the stated duration provided herein.
www.westmountainradio.com
1020 Spring City Drive, Waukesha, WI 53186
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