Spektrum SPMSR3520 User Manual

SR3520 Instruction Manual

Spektrum’s SR3520 3-channel DSM2™ Micro Race receiver is compatible with Spektrum DSM2
surface transmitters and operates in DSM2 mode.

Specifications:

Type: DSM2
Channels: 3
Band: 2.4GHz
Dimensions (LxWxH): 1.0 x 0.8 x 0.5 in (26 x 21 x 12mm)
Weight: .1 oz (4 g)
Voltage Range: 3.5–9.6V

Note: If using a DX3R and 5.5ms frame rate is selected, only two channels (steering and

throttle) are operational.

Binding Receiver to Transmitter

In order to operate, the receiver must be bound to the transmitter. Binding is the process of
teaching the receiver the specific transmitter’s code called GUID (Globally Unique Identifier).
When a receiver is bound to a transmitter/model memory, the receiver will only respond to that
specific transmitter/model memory.

Bind Plug

LED

Binding
Note: The SR3520 receiver utilizes the DSM2 protocol and is only compatible with DSM2

surface transmitters such as the DX3R.

1. With the receiver off, insert the bind plug into the BIND port in the receiver.

2. Power the receiver through any port. If an ESC is being used, power on the ESC with the
ESC lead plugged in the throttle channel port. The orange LED will flash continuously
indicating that the receiver is in bind mode.

Powering the receiver with a separate
receiver pack

3. With the steering wheel, throttle trigger and Aux channel (if applicable) in the desired preset
failsafe positions, initiate the bind process with your Spektrum transmitter which will also
store the failsafe positions. Please see the next section for more information about Failsafe.

4. The LED on the receiver should now be solid, indicating a successful bind has taken place.

Powering the receiver with an ESC

5. Once the bind process is complete and before power is cycled on the receiver, remove the
bind plug and store it in a convenient place. Failure to remove the bind plug will result in
the receiver going back into bind mode.

Note: The only time it is necessary to do a rebind is if different failsafe positions are desired

e.g., servo travel has been reversed after the initial bind, or if the receiver is to be
bound to a different model memory.

Failsafe

Failsafe positions are also set during binding. In the unlikely event that the radio link is lost
during use, the receiver will drive the servos to their preprogrammed failsafe positions (normally
full brakes and straight steering). If the receiver is turned on prior to turning on the transmitter,
the receiver will enter failsafe mode, driving the servos to their preset failsafe positions. When
the transmitter is turned on, normal control is resumed.

Tips on Using Spektrum 2.4GHz

Your DSM equipped 2.4GHz system is intuitive to operate, functioning nearly identically to FM
systems. Following are a few common questions from customers.

1. Q: Which do I turn on first, the transmitter or the receiver?

A: It doesn’t matter, although it is suggested to turn the transmitter on first. If the receiver is
turned on first, all channels will be driven to the failsafe position set during binding. When the
transmitter is then turned on, the transmitter scans the 2.4GHz band and acquires an open
channel. Then the receiver that was previously bound to the transmitter scans the band and
finds the GUID (Globally Unique Identifier code) stored during binding. The system then connects
and operates normally. If the transmitter is turned on first, the transmitter scans the 2.4GHz
band and acquires an open channel. When the receiver is turned on, the receiver scans the

2.4GHz band looking for the previously stored GUID. When it locates the specific GUID code and

confirms uncorrupted repeatable packet information, the system connects and normal operation
takes place. Typically this takes 2 to 6 seconds.

2. Q: Sometimes the system takes longer to connect and sometimes it doesn’t connect
at all?

A: In order for the system to connect (after the receiver is bound) the receiver must receive
a large number of consecutive uninterrupted perfect packets from the transmitter in order to
connect. This process is purposely critical of the environment ensuring that it’s safe to drive or
fly when the system does connect. If the transmitter is too close to the receiver (less that 4 ft.)
or if the transmitter is located near metal objects (metal TX case, the bed of a truck, the top of
a metal work bench, etc.) connection will take longer and in some cases connection will not
occur as the system is receiving reflected 2.4GHz energy from itself and is interpreting this as
unfriendly noise. Moving the system away from metal objects or moving the transmitter away
from the receiver and powering the system again will cause a connection to occur. This only
happens during the initial connection. Once connected the system is locked in and should a loss
of signal occur (failsafe) the system connects immediately (4ms) when signal is regained.

3. Q: I’ve heard that the DSM system is less tolerant of low voltage. Is that correct?

A: All DSM receivers have an operational voltage range of 3.5 to 9.6 volts. With most systems
this is not a problem as in fact most servos cease to operate at around 3.8 volts. When using
multiple high-current draw servos with a single or inadequate battery/power source, heavy
momentary loads can cause the voltage to dip below this 3.5-volt threshold thus causing the
entire system (servos and receiver) to brown out. When the voltage drops below the low voltage
threshold (3.5 volts), the DSM receiver must reboot (go through the startup process of scanning
the band and finding the transmitter) and this can take several seconds. Please read the receiver
power requirement section as this explains how to test for and prevent this occurrence.

4. Q: Sometimes my receiver loses its bind and won’t connect, requiring rebinding. What
happens if the bind is lost during use?

A: The receiver will never lose its bind unless it’s instructed to. It’s important to understand that
during the binding process the receiver not only learns the GUID (code) of the transmitter but the
transmitter learns and stores the type of receiver that it’s bound to.

If the system fails to connect, more than likely the transmitter is near conductive material
(transmitter case, truck bed, etc.) and the reflected 2.4GHz energy is preventing the system from
connecting. (See #2 above)

Warranty Period

Exclusive Warranty- Horizon Hobby, Inc., (Horizon) warranties that the Products purchased (the
“Product”) will be free from defects in materials and workmanship for a period of 1 year from the
date of purchase by the Purchaser.

Limited Warranty

(a) This warranty is limited to the original Purchaser (“Purchaser”) and is not transferable. REPAIR
OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE REMEDY OF THE
PURCHASER. This warranty covers only those Products purchased from an authorized Horizon dealer.
Third party transactions are not covered by this warranty. Proof of purchase is required for warranty
claims. Further, Horizon reserves the right to change or modify this warranty without notice and
disclaims all other warranties, express or implied.

(b) Limitations- HORIZON MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR IMPLIED,
ABOUT NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OF
THE PRODUCT. THE PURCHASER ACKNOWLEDGES THAT THEY ALONE HAVE DETERMINED THAT THE
PRODUCT WILL SUITABLY MEET THE REQUIREMENTS OF THE PURCHASER’S INTENDED USE.

(c) Purchaser Remedy- Horizon’s sole obligation hereunder shall be that Horizon will, at its option,
(i) repair or (ii) replace, any Product determined by Horizon to be defective. In the event of a defect,
these are the Purchaser’s exclusive remedies. Horizon reserves the right to inspect any and all
equipment involved in a warranty claim. Repair or replacement decisions are at the sole discretion
of Horizon. This warranty does not cover cosmetic damage or damage due to acts of God, accident,
misuse, abuse, negligence, commercial use, or modification of or to any part of the Product. This
warranty does not cover damage due to improper installation, operation, maintenance, or attempted
repair by anyone other than Horizon. Return of any goods by Purchaser must be approved in writing
by Horizon before shipment.

Damage Limits

HORIZON SHALL NOT BE LIABLE FOR SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, LOSS OF
PROFITS OR PRODUCTION OR COMMERCIAL LOSS IN ANY WAY CONNECTED WITH THE PRODUCT,
WHETHER SUCH CLAIM IS BASED IN CONTRACT, WARRANTY, NEGLIGENCE, OR STRICT LIABILITY.
Further, in no event shall the liability of Horizon exceed the individual price of the Product on which
liability is asserted. As Horizon has no control over use, setup, final assembly, modification or misuse,
no liability shall be assumed nor accepted for any resulting damage or injury. By the act of use, setup
or assembly, the user accepts all resulting liability.

If you as the Purchaser or user are not prepared to accept the liability associated with the use of this
Product, you are advised to return this Product immediately in new and unused condition to the place
of purchase.

Law: These Terms are governed by Illinois law (without regard to conflict of law principals).

Safety Precautions

This is a sophisticated hobby Product and not a toy. It must be operated with caution and common sense
and requires some basic mechanical ability. Failure to operate this Product in a safe and responsible
manner could result in injury or damage to the Product or other property. This Product is not intended
for use by children without direct adult supervision. The Product manual contains instructions for safety,
operation and maintenance. It is essential to read and follow all the instructions and warnings in the
manual, prior to assembly, setup or use, in order to operate correctly and avoid damage or injury.

Questions, Assistance, and Repairs

Your local hobby store and/or place of purchase cannot provide warranty support or repair. Once
assembly, setup or use of the Product has been started, you must contact Horizon directly. This will
enable Horizon to better answer your questions and service you in the event that you may need any
assistance. For questions or assistance, please direct your email to
[e-mail], or call 877.504.0233 toll free to speak to the
Product Support department.

Inspection or Repairs

If this Product needs to be inspected or repaired, please call for a Return Merchandise Authorization
(RMA). Pack the Product securely using a shipping carton. Please note that original boxes may be
included, but are not designed to withstand the rigors of shipping without additional protection. Ship
via a carrier that provides tracking and insurance for lost or damaged parcels, as Horizon is not
responsible for merchandise until it arrives and is accepted at our facility. A Service Repair Request is
available at www.horizonhobby.com on the “Support” tab. If you do not have internet access, please
include a letter with your complete name, street address, email address and phone number where
you can be reached during business days, your RMA number, a list of the included items, method
of payment for any non-warranty expenses and a brief summary of the problem. Your original sales
receipt must also be included for warranty consideration. Be sure your name, address, and RMA
number are clearly written on the outside of the shipping carton.

Warranty Inspection and Repairs

To receive warranty service, you must include your original sales receipt verifying the proof-of­purchase date. Provided warranty conditions have been met, your Product will be repaired or
replaced free of charge. Repair or replacement decisions are at the sole discretion of Horizon Hobby.

Non-Warranty Repairs

Should your repair not be covered by warranty the repair will be completed and payment will be
required without notification or estimate of the expense unless the expense exceeds 50% of the
retail purchase cost. By submitting the item for repair you are agreeing to payment of the repair
without notification. Repair estimates are available upon request. You must include this request with
your repair. Non-warranty repair estimates will be billed a minimum of ½ hour of labor. In addition
you will be billed for return freight. Please advise us of your preferred method of payment. Horizon
accepts money orders and cashiers checks, as well as Visa, MasterCard, American Express, and
Discover cards. If you choose to pay by credit card, please include your credit card number and
expiration date. Any repair left unpaid or unclaimed after 90 days will be considered abandoned and
will be disposed of accordingly. Please note: non-warranty repair is only available on electronics and
model engines.

Electronics and engines requiring inspection or repair should be shipped to the following address:

Horizon Service Center

4105 Fieldstone Road

Champaign, Illinois 61822

All other Products requiring warranty inspection or repair should be shipped to the following address:

Horizon Product Support

4105 Fieldstone Road

Champaign, Illinois 61822

Please call 877-504-0233 or e-mail us at [e-mail] with any questions or
concerns regarding this product or warranty.

European Union:

Electronics and engines requiring inspection or repair should be shipped to one of the following

addresses:

Horizon Hobby UK

Units 1-4 Ployters Rd

Staple Tye, Harlow

Essex CM18 7NS

United Kingdom

Please call [phone] or email [e-mail] with any questions or
concerns regarding this product or warranty.

Horizon Technischer Service

Hamburger Str. 10

25335 Elmshorn

Germany

Please call [phone] or email [e-mail] with any questions or concerns
regarding this product or warranty.

FCC Information

This device complies with part 15 of the FCC rules. Operation is subject to the following two
conditions: (1) This device may not cause harmful interference, and (2) this device must
accept any interference received, including interference that may cause undesired operation.

Caution: Changes or modifications not expressly approved by the party responsible for

compliance could void the user’s authority to operate the equipment.

This product contains a radio transmitter with wireless technology which has been tested
and found to be compliant with the applicable regulations governing a radio transmitter in the

2.400GHz to 2.4835GHz frequency range.

Instructions for Disposal of WEEE by Users in
the European Union

This product must not be disposed of with other waste. Instead, it is the user’s
responsibility to dispose of their waste equipment by handing it over to a
designated collection point for the recycling of waste electrical and electronic

equipment. The separate collection and recycling of your waste equipment at
the time of disposal will help to conserve natural resources and ensure that it is recycled in a
manner that protects human health and the environment. For more information about where
you can drop off your waste equipment for recycling, please contact your local city office, your
household waste disposal service or where you purchased the product.

Declaration of Conformity

(in accordance with ISO/IEC 17050-1)

No. HH20081021

Product(s): Spektrum SR3520 Receiver
Item Number(s): SPMSR3520

Equipment class: 1

The objects of declaration described above are in conformity with the requirements of the
specifications listed below, following the provisions of the European R&TTE directive 1999/5/EC:

EN 300-328 v1.7.1 ERM requirements for wideband transmission systems

operating in the 2.4 GHz ISM band

EN 301 489-1 v.1.6.1 General EMC requirements for Radio equipment
EN 301 489-17 v.1.2.1

Signed for and on behalf of:
Horizon Hobby, Inc.
Champaign, IL USA
Oct 21, 2008

Steven A. Hall
Vice President
International Operations and Risk Management
Horizon Hobby, Inc.

DSM and DSM2 are trademarks or registered trademarks of Horizon Hobby, Inc. The Spektrum trademark is

used with permission of Bachmann Industries, Inc. Spektrum radios and accessories are exclusively available

Printed 10/08 14678

from Horizon Hobby, Inc.