Narco Avionics HT870 User manual

NARCO HT870
HANDHELD NAV/COM
960 CHANNELS

i
TABLE OF CONTENTS
1.1INTRODUCTION .................................................................... 1
2.1PRODUCT DESCRIPTION ............................................................. 1
3.1DESIGN FEATURES ................................................................. 1
4.1SPECIFICATIONS .................................................................. 2
5.1PRELIMINARY INSPECTION AND UNPACKING ............................................ 3
5.2HT870 AND SUPPLIED ACCESSORIES .................................................. 3
6.1HT870 MAINTENANCE INFORMATION ................................................... 4
7.1USE OF EXTERNAL MICROPHONE ...................................................... 4
8.1USE OF EXTERNAL HEADPHONES OR SPEAKER ........................................... 5
9.1HT870 LICENSE REQUIREMENTS ...................................................... 5
10.1 NICKEL CADMIUM (NiCad) BATTERY PACK SPECIFICATIONS................. 5
10.2 BATTERY PACK CHARGING.............................................. 6
10.3 BATTERY PACK INSTALLATION.......................................... 7
10.4 QUICK CHANGING THE BATTERY PACK TO PRESERVE MEMORY................. 7
10.5 OPTIONAL ALKALINE BATTERY PACK..................................... 7
11.1 ADDITIONAL ANTENNA CONSIDERATIONS.................................. 8
12.1 CAUTIONS TO OPERATORS.............................................. 8
13.1 DESCRIPTION AND LOCATION OF CONTROLS............................... 9
13.1.1 HT870 TOP PANEL DESCRIPTION........................................ 10
13.2 16-KEY KEYBOARD DESCRIPTION........................................ 10
13.3 PRODUCT DESCRIPTION HT870.......................................... 11
14.1 INTRODUCTION TO OPERATING PROCEDURES............................... 14
14.2 POWER TURN-ON AND VOLUME CONTROL................................... 15
14.3 SQUELCH CONTROL OPERATION.......................................... 15
14.4 FREQUENCY ENTRY.................................................... 16
14.5 FREQUENCY ASSIGNMENTS TO MEMORY.................................... 16
14.5.1 PROGRAMMING OF LOCATIONS M0 TO M9.................................. 16
14.5.2 RECALLING FREQUENCY FROM MEMORY LOCATION........................... 18
14.6 OPERATION OF THE HT870 AS A COM TRANSCEIVER........................ 18
14.6.1 FREQUENCY MODE OF OPERATION (COM CHANNELS)......................... 18
14.6.1.1 FREQUENCY MODE SINGLE FREQUENCY OPERATION.......................... 18
14.6.1.2 FREQUENCY MODE SCANNING............................................ 18
14.6.2 MEMORY MODE OF OPERATION........................................... 19
14.6.2.1 MEMORY LOCATION LOCKOUT............................................ 20
14.6.2.2 RESTORING A LOCKED OUT MEMORY LOCATION TO THE SCAN SEQUENCE........ 22
14.7 VOR NAV OPERATION.................................................. 22
14.7.1 CDI MODE........................................................... 22
14.7.1.1 SETTING THE OBS.................................................... 23
14.7.1.2 AUTO CENTERING..................................................... 23
14.7.1.3 BEARING MODE....................................................... 23
14.7.2 DUPLEX OPERATION IN NAV MODE....................................... 24

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LIST OF ILLUSTRATIONS
13-1 HT870 CONTROL FUNCTIONS 9
13-2 MIC CONNECTOR PIN ASSIGNMENT 10
13-3 16-KEY KEYBOARD 10

1
1.1 INTRODUCTION
This manual contains product description, features, specifications, available
options and operating instructions.
It is not intended as a maintenance manual, therefore, service information in
the form of theory, alignment or schematics is not provided.
2.1 PRODUCT DESCRIPTION
The Narco HT870 is a microprocessor controlled hand held 760 channel
communication transceiver covering the band of 118 to 136.975 MHz and a 200
channel NAV receiver covering the band of 108 to 117.95 MHz. The HT870
antenna is removable and may be connected to the aircraft's COM antenna.
Nav and COM frequencies are displayed on a liquid crystal display (LCD) and
are entered on an easy to use 16-key keyboard. Ten pre-programmable NAV or
COM frequencies may be stored in a non-volatile memory and manually selected
for use or automatically scanned. A memory lockout feature is provided in
which programmable frequencies can be locked out of the automatic or manual
scan.
The HT870 is powered by a rechargeable, quickly changed, NiCad battery pack.
An optional nonrechargeable alkaline battery pack for emergency use is
available. The user is alerted when the battery pack voltage has dropped
below its useable limit by the appearance of the letters "BATT" in the
display. The liquid crystal display can be illuminated to facilitate viewing
in darkness.
3.1 DESIGN FEATURES
Microprocessor controlled circuitry
760 COM channels
200 NAV channels
10 pre-programmable nonvolatile memory locations
Keyboard data entry
Large Liquid Crystal Display (LCD)
Quickly changed, rechargeable NiCad battery pack
Scanning Modes: Memory, Scan
Priority channel scanning in SCAN mode
Squelch-Adjust Control
Nominal 2 watts RF Transmitter
Lightweight, 1 lb. 4 oz. (570 grams)
Receiver sensitivity 1.5 microvolts for 6 dB S+N/N
Separate external speaker/microphone jack
Inputs for normal and quick charge
Quick removable (BNC) antenna
Quick slideoff battery pack
VOR displayed in CDI/BRG modes.

2
4.1 SPECIFICATIONS
GENERAL
Navigation channels: 200 (50 KHz steps) from 108.00 to 117.95 MHz
Communication channels: 760 (25 KHz steps) from 118.00 to 136.975 MHz
Memory Channels: 10 Channels
Weight: 1 lb. 4 oz (570 grams)
Dimensions: Width 2.44 in. (62 mm) Height 7.05 in. (179 mm)
Depth 1.54 in. (39 mm)
TRANSMITTER
Power: 1.5 watts carrier (minimum), 2 watts nominal
Frequency Stability: ±0.002%
Modulation: 6A3, 70% minimum
Frequency range: 118.00 to 136.975 MHz (760 channels)
Spurious radiation: -46 dB below carrier
Antenna impedance: 50 ohms
RECEIVER
Frequency range: NAV (108.00 to 117.95 MHz)
COM (118.00 to 136.975 MHz)
Audio output: 0.5 watts into 8 ohms (speaker)
30 milliwatts into 600 ohms (headphones)
Receiver sensitivity: 1.5 microvolts max for 6 dB S+N/N
Image rejection: 50 dB or greater
Receiver selectivity: 6 dB ±15 KHz, 60 dB ±30 KHz
Squelch Sensitivity: Adjustable carrier, AGC type
POWER SOURCE
9.6 Vdc, 600 mA, NiCad Battery
Battery full charge time: 150 mA maximum @ 5 hrs (using optional base
charger. Part Number 50906-0001)
45 mA maximum @ 17 hrs (using supplied wall charger)
Battery life per charge: Receive only: 8 hrs.
(Approximate) Transmit 10% duty: 4-6 hrs.
Transmit 30% duty: 2-4 hrs.
Number of battery recharges (full discharge to full charge): up to 300
TEMPERATURE
Operating range: -30 to +50 degrees C

3
5.1 PRELIMINARY INSPECTION AND UNPACKING
Upon receipt of the HT870, inspect the shipping container to attempt to
determine if equipment may have been damaged during shipment. Note damage, if
any.
Carefully unpack the unit and inspect it for any damage that may have occurred
during shipment. Refer to Sections 5.2 and 5.3 and inventory the contents of
your shipment.
5.2 HT870 AND SUPPLIED ACCESSORIES
An HT870 is ordered using part number 03117-0300. This part number is
comprised of the following items:
ITEM QTY DESCRIPTION
1 1 HT870 Handheld NAV/COM
2 1 NiCad rechargeable Battery Pack (Part No. 50900-0001)
3 1 Battery Wall Charger (Part No. 50901-0001)
4 1 Flexible Antenna (Part No. 50902-0001)
5 1 Operator's Manual (Part No. 03125-0621)
5.3 HT870 OPTIONAL ACCESSORIES
The following list comprises the available accessories for the HT870:
ITEM ORDER
NUMBER DESCRIPTION
1 50900-0002 Nonrechargeable alkaline battery pack
2 50900-0001 Rechargeable NiCad battery pack (9.6 Vdc/500
maH)
3 50905-0001 Leather cowhide case with snap-off front flap,
build in belt clip.
4 50902-0001 Flexible rubberized antenna with BNC connector
5 50907-0001 Handheld remote combination speaker/microphone
complete with connector ready to use. No
adjustments necessary. For ground use only.
Not recommend for use in aircraft.
6 50932-0001 Mobile NiCad battery charger. Plugs into
cigarette lighter of aircraft or car, which
permits NiCad battery charging or operation of
the HT870.
7 50906-0001 Desktop quick charger and stand. The HT870 is
placed upright into a well in the stand which
permits the quick-charging (5 hrs.) of the
HT870's installed NiCad battery pack.

4
5.3 Continued
7 50906-0001 The HT870 may be operated in both
(Cont.) receive and transmit modes while it is charging,
but ONLY when a NiCad battery pack has been
installed.
8 50926-0101 6 inch adapter cable which permits the
interfacing of aircraft type headphones and
microphones to the HT870. One end of the cable
connects to the HT870's top panel external
speaker/microphone connector; installed on the
other end of the cable are standard headphone
and microphone jacks. An external push-to-talk
switch must be supplied and installed by the
owner to complete the interface.
9 50908-0001 External speaker/microphone connector only.
Mates to the HT870's top panel external
speaker/microphone connector. This connector is
used when the owner wishes to design and
fabricate his own interface adapter cable (see
item 8).
6.1 HT870 MAINTENANCE INFORMATION
The HT870 is not field repairable. Should a service problem arise, write a
note explaining the problem. Include in the note you name, shipping address,
and type of shipping desired (UPS, Federal Express, etc.) Include the note
with the HT870 and ship prepaid to:
NARCO AVIONICS, INC.
270 Commerce Drive
Fort Washington Industrial Park
Fort Washington, PA 19034
Attn: Factory Service Dept.
7.1 USE OF EXTERNAL MICROPHONE
The use of a good noise cancelling microphone is highly recommended when using
the HT870 in an aircraft environment. The HT870's internal microphone is
rendered inoperative when an external microphone that has been connected to
the top panel speaker/microphone connector and the Internal/External switch is
in the "E" position.

5
7.1 Continued
Any current popular aircraft microphone may be used; the only exception being
carbon microphones. They require more current than is available from the
HT870 and therefore would not perform adequately.
8.1 USE OF EXTERNAL HEADPHONES OR SPEAKER
The HT870's internal speaker is rendered inoperative when an external speaker
or headphones are connected to the HT870's top panel mic. jack. The
Internal/External switch must be in the "I/E" or "E" position. Headphone
impedance should be 600 ohms minimum, and speaker impedance should be 8 ohms.
9.1 HT870 LICENSE REQUIREMENTS
If the HT870 is to be used as an aircraft transceiver, the Federal
Communications Commission requires that FCC Form 404 titled "Application for
Aircraft Radio Station License" be submitted prior to operation.
If the HT870 is to be used as a ground station, the FCC Form 406 titled
"Application for Ground Station Authorization in the Aviation Services" must
be submitted prior to operation.
10.1 NICKEL CADMIUM (NiCad) BATTERY PACK SPECIFICATIONS
Nominal Operating Voltage: 9.6 Vdc
Nominal Capacity: 600 milliamp hour
"Fully Charged State" Output Voltage: 10.8 to 11.6 Vdc
"Discharged State" Output Voltage: 8 Vdc
Quick Charge: 150 mA max/5-6 hours for full charge
Standard Charge: 45 mA/16-17 hours for full charge
Advisable Temperature Ranges: Charging: 10 to 40 degrees C
Discharging: -30 to 60 degrees C
Storage (3 months): -30 to 50
degrees C

6
10.1 Continued
3 Months Storage Characteristics (battery fully charged and NOT
connected to HT870):
Storage Temperature: 0 degrees C (32 degrees F) 10 to 20 % drop
in battery capacity through self-
discharge
20 degrees C (59 degrees F) 30 to 40% drop in
battery capacity through self-
discharge
Note: At a storage temperature of 45 degrees C (113 degrees F),
after 1.5 months the battery capacity has dropped by 95%.
Battery Service Life: 300 charge/discharge cycles (minimum)
Memory Effect: NiCad batteries have a "memory effect", where the
battery voltage drops in 2 levels during operation
(discharge). The first level drop is approximately 8% reduction
in capacity for the first 30 to 40 minutes of operation followed
by a sharp 60% drop in capacity during the next 10-15 minutes of
operation. This "memory effect" is caused by repeatedly charging
the batteries when they have been only slightly discharged. This
is a temporary problem which can be rectified by performing 2 to 3
complete discharge/charge cycles.
10.2 BATTERY PACK CHARGING
CHARGING
CHARGING DEVICE CURRENT CHARGING TIME
Wall Charger (supplied 45 mA 16-17 hours for a
with HT870) (Standard full charge;
charge rate) however, charger may
be left on indefinitely
Optional Mobile Adapter 45 mA 15-16 hours for a
(cigarette lighter plug) full charge with
Note: Some mobile lighter radio turned OFF.
sockets are "off" if Radio may be
the ignition switch operated with
is "off". charger plugged in but
batteries will not charge
because charging current
is used by the radio.
Optional Desktop Quick ----- 1 hour with
Charger and stand radio turned off for
a full charge (See note).

7
10.2 Continued
Note: The HT870, when turned off, may be left on the quick charger
indefinitely without harm to the battery pack.
The HT870 may be operated both in the receive and transmit modes while being
charged in the Desktop quick charger/stand; however, the battery charging rate
drops back to the standard rate (17 hours) because a portion of the charging
current is used to power the radio.
10.3 BATTERY PACK INSTALLATION
To remove the Battery Pack, depress the Battery Lock button and slide it off
in the direction of the Lock Button. To install it, slide the Battery Pack
onto the bottom of the unit, ensuring the lock button clicks up.
CAUTION: Never store an HT870 with the NiCad battery pack connected.
There is internal circuitry that is always connected to the
battery bus that draws a small amount of current
(microamperes) which will deplete that battery's charge
within 3 weeks. Always store the HT870 with the battery
disconnected.
10.4 QUICK CHANGING THE BATTERY PACK TO PRESERVE MEMORY
If a battery pack that needs recharging is being replaced by a second fully
charged pack, the exchange must be completed within 30 seconds. Failure to do
so will result in the erasure of all operator selected frequencies stored in
memory (m0 to m9). Always turn the HT870's power switch OFF before installing
or removing a battery pack.
10.5 OPTIONAL ALKALINE BATTERY PACK
An optional nonrechargeable alkaline battery pack is available for the HT870
(see Section 5.3). This battery pack is an ideal choice for an emergency
back-up power source as it has a storage life of approximately 2 years. The
service life of the battery pack is approximately 20 hours when operating the
HT870 in the receive mode. Alkaline batteries may be changed within this
pack.
CAUTION: 1. DO NOT try to recharge the alkaline battery.
2. Never store an HT870 with the battery pack connected.
There is internal circuitry that is always connected
directly to the battery bus that draws a small amount
of current (microamperes) which will deplete the
battery over time. Always store the HT870 with the
battery disconnected. When batteries are changed with
a pack observe polarity.