Drake VM2551A User Manual
VM2551A
AGILE COMMERCIAL VIDEO MODULATOR
( F o r U s e i n N T S C S y s t e m s )
I N S T R U C T I O N M A N U A L
VM2551A VIDEO MODULATOR
® is a registered trade mark of the R .L . Dra ke Holdings LLC
© Copyright 2013 R .L . Dra ke Holdings LL C P/N: P rinted in China.
651232400A
V001 12102013
1002412A/1002423A
2 Caution Statements
WAR NING : T O P R E VE NT FIR E OR
E LE C TR IC AL S HOC K , DO NO T
E XP OS E T O R AIN OR MO IS TUR E
with care. Quick stops, excessive force and uneven
surfaces may cause the product and cart combination
to overturn.
The lightning ash with arrow head symbol, within an
equilateral triangle, is intended to alert the user to the
presence of uninsulated "dangerous voltage" within
the product's enclosure that may be of su fcient
magnitude to constitute a risk of electric shock to
persons.
The exclamation point within an equilateral triangle is
intended to alert the user to the presence of important
operating and maintenance (servicing) instructions in
the literature accompanying the product.
WAR NIN G : TO R E DUC E T H E R IS K OF F IR E O R E LE C TR IC S HOC K, DO NOT E XP OS E THIS P R O DUC T TO
R AIN O R MO IS TUR E .
DO NOT OP E N T HE C AB INE T, R EF E R S E RV IC ING T O QUAL IF IE D P E R S ON NE L O NLY.
CA UTI ON: TO P R E VE NT ELE C T R IC SHOC K, DO NOT U S E T H IS (P OLAR IZ E D) P LUG WIT H AN E XT E N S ION
C O RD R E CE PTAC LE O R O T HE R OUT L E T UN LE S S T H E B L ADE S C AN B E F ULLY INS E R TE D T O
P R E VE NT B LADE E XP OS UR E .
ATT E NTI ON: P OU R P R E VE NIR L E S C HO C S E LE C TR IQ UE S , NE PAS U T ILIS E R C ET T E F IC HE P O L AR IS E E
AVE C UN P ROLO NG AT E UR , UNE P R IS E DE C OU R AN T OU UNE AUT R E S OR TIE DE C OUR ANT,
S AUF S I L E S L AME S P E UVE NT ET R E INS E R E E S A FO ND S ANS E N LAIS S ER AUC U NE PAR TIE A
DE C OUVE R T.
A product and cart combination should be moved
Important S afet y Inst ruc tions :
1. Re ad Inst ruc tions : All the safety an d opera ting ins tructions should be read before the product is operated.
2. Ret ain Inst ruc tions : The safety and operating ins tructions should be retained for future reference.
3. He ed War ning s: All warnings on the product an d in the oper ating instructions should be adhere d to.
4. Follo w Inst ru ctio ns: All operating an d use ins tructions should be followed.
5. C leanin g: Unplug this produc t from the wa
6. Atta c hments : Do not use attachments that are not recommended by the product manufa cturer a s they may cause hazard s.
7. W ater and Mois ture: Do not us e this product nea r water—for e xample, nea r a bathtub, wash bowl, kitchen sink or laundry tub; in a wet bas ement;
or nea r a swimming pool; and the like.
8. Acces s ories : D o not place this product on an unstable cart, stand, tripod, bracket, or table. The product ma y fall, causing serious injury to a c hild
or adult, and serious damag e to the product. Us e only with a cart, stand, tripod, brack et, or table recommend
the product. Any mounting of the product s hould follow the manufa cturer's ins tructions, and shoul d us e a mounting accessor y recommende d by the
manufa cturer.
9. A product and cart combination s hould be moved with care. Quick stops, excessiv e force, and uneve n surface s may caus e the product and cart
combination to overturn.
10. Ven tilatio n: S lots and openings in the cabin et are provided for ventilation and to ensur e reliable opera tion of the product and to protect it from
overh
e ating, an d these openings must not be blocked or covered. The openings should neve r be blocked by placing the product on a bed, sofa, rug,
or similar surface. T his product s hould not be placed in a built-in ins talla tion such as bookcas e or rac k unless proper ventilation is provided or the
manufa cturer's ins tructions have been adhered to.
11. Po wer So urce s : T his product should be opera ted only from the type of power source indicated on the marking label. If you
of power supplied to your home, consult your product deale r or local power compa ny. F or products intended to oper ate from ba ttery power, or other
sources , re fer to the operating instructions.
12. Groundin g or Po lariza tion: T his product may be equipped with a polarized alternating-current line plug (a plug having one blade wider than the
other). T his plug will fit into the power outlet only one way. T his is a sa fety feature. If you are unab
the plug. If the plug s hould still fail to fit, contact your electrician to replac e your obsolete outlet. Do not defea t the sa f
plug. Alternate Warning s – If this product is equippe d with a three-wir e grounding- type plug, a plug havin g a third (grounding) pin, the plug will only fit
into a grounding-type power outlet. This is a s afety feature. If you are unable to inse rt the plug into the ou
obsolete outlet. D o not defeat the safety purpos e of the grounding-type plug.
ll outlet before cleaning. Do not us e liquid c leaners or aerosol c lean sers . Us e a damp c loth for cleanin g.
e d by the manufa ct
are not sur e of the type
le to inse rt the plug fully into the outlet, try reve rsing
ety purpose of the polarized
tlet, co ntact your electrician to repla ce your
Caution Statements (continued)
Outdoor Antenna Grounding: If an outside antenna or cable system is connected to the product, be sure the antenna or cable system is
13.
grounded so as to provide some protection against voltage surges and built-up static charges. Article 810 of the National Electrical Code,
ANSI/NF PA 70, provides information with regard to proper grounding of the mast and supporting structure, grounding of the lead-in wire t o an
antenna discharge unit, size of grounding conductors, location of antenna-discharge unit, connection to grounding electrodes, a nd requirements for
the grounding electrode.
14. Power-C ord P ro tec tion: Power-s upply cords should be routed so that they ar e not likely to be walked on or pinched by items placed upon or aga inst
them, paying pa rticular attention to cords at plugs, convenience re ceptacles, and the point where they exit from the product.
15. Li ghtni ng: F or adde d protection for this product during a lightning storm, or when it is left unattended and unus ed for long periods of time, unplu
from the wall outlet and dis connect the antenna or cable sys tem. T his will prevent dama ge to the product due to lightning a nd power-line surges .
16. Power L ines : An outside antenna sys tem should not be located in the vicinity of overhea d power lines , other el ectric light or power c ircuits, where it
can fa ll into s uch power lines or circuits. When installing an outside a ntenna s ystem, extreme ca re should be taken to keep from touch
lines or circuits as contact with them may be fatal.
17. Ov erlo adin g: Do not overload wall outlets, extension cords, or integral convenience re ceptacles as this can result in a risk of fire or e lectric s hock.
18. Objec t and Liqu id E ntry : Ne ver push objec ts of a ny kind into this product through openings as they ma y touch dangero us voltage points or short-out
parts that could result in a fire or elec tric shock. Ne ver s pill liq
19. S ervic ing: Do not a ttempt to service this product yourse lf as opening or re moving covers ma y expo se you to dangerous voltage or other haz ards.
R efer all serv icing to qualified s ervice pers onnel.
20. Dama ge R equiring S erv ice: Unplug this product from the wa ll outlet and refer servicing to qualified s ervice pers onnel under the following conditions:
a) When the power-s upply cord or plu
b) If liquid has been spill ed, or objects have fallen into the product,
c) If the product has been expose d to ra in or water,
d) If the product doe s not opera te normally by following the operating instructions.
A djust only those controls that are covered by the operating instructions as a n improper adjustment of other controls may result in damage and will
often requi re extens ive work by a qualified technician to restore the pro
in a ny way, and f. W hen the product exhibits a distinct chan ge in performanc e—this indica tes a need for service.
21. R eplace m ent P art s: W hen replacement pa rts are require d, be sure the service technicia n has used replaceme nt parts specified by the ma nufac turer
or have the s ame chara cteristics as the original pa rt. Unauthorized s ubstitutes may res u
22. S afety C hec k: Upon completion of any service or repairs to this product, as k the service technicia n to perform safety checks to de termine that the
product is in proper opera ting condition.
23. Wall or Ce iling Mounting: T he product shou ld be mounted to a wall or ceiling only as recommend ed by the manufacturer.
24. Heat: T he product should be situated away from heat source s such as radiators, heat registers , stoves , or other pro
produce heat.
g is damag ed,
uid of any kind on the product.
duct to its normal operation, e. If the product has been dropped or damaged
lt in fire, electric shock or other hazar ds .
ducts (including amplifiers ) that
3
g it
ing such power
4 Table of Contents / Description / Specications
TABLE OF CONTENTS
2 Caution Statements
2 Important Safety Instructions
4 Table of Contents / Description / Specications
5 Front / Rear Panel Controls and Indicators
6 Operation
7 Adjustments
8
Channel Assignments
10
Service / If You Need to Call For Help
11
Warra nty
VM2551A VIDEO MODULATOR
DESCRIPTION
The R.L. Drake VM2551A Agile Video Modulator is a high quality,
vestigial sideband unit with synthesized visual and aural carriers.
It is designed to accept NTSC video and audio baseband signals from
a satellite receiver or similar equipment. Front panel video and audio
level controls with accompanying modulation indicators permit easy
setup of the proper modulation levels. The A/V ratio and RF output level
controls are also provided on the front panel. A rear panel EAS alternate
IF input is also provided.
Synthesized operation provides complete frequency agility, allowing
front panel selection of any standard CATV channel from 2 to 78. FCCrequired osets for aeronautical channels are automatically provided for
each channel that requires an oset. For special applications, IRC or HRC
CATV frequencies or o-air broadcast frequencies can be selected from
the front panel.
A high quality IF SAW lter with FCC pre-distortion eliminates adjacent
channel interference and provides optimum delay characteristics.
SPECIFICATIONS
VIDEO INPUT
Connector: F-Type (Female)
Impedance: 75 ohms
Return Loss: 18 dB
Video Input Level: 0.7 volt Peak-to-Peak
Signal-to-Noise Rao: 58 dB
Differenal Gain: 2.0%
Differenal Phase: 1.0 degree
Over-modulaon Indicator: 87 to 92%
L/C Delay: Per FCC Requirements
RF OUTPUT
Connector: F-Type (Female)
Impedance: 75 ohms
Return Loss: 12 dB
Channel Modes: CATV (STD, IRC, HRC), UHF, VHF
Power Level Range: +50 to +60 dBmV (in 0.2 dB increments)
Video Flatness: fv-0.5 to fv+4.2 MHz: 1.5 dB p/v
Carrier-to-Noise: -63 dB
Broadband Noise: -77 dBc
Spurious Outputs: -63 dBc
Aural/Visual Carrier Rao: -15 ± 5 dB
GENERAL
AC Power: 117 VAC ± 10%, 60 Hz, 23 Wa max
Fuse: 0.4A Type T 250 V
Temperature Range: 32° to 122° F
Size: 19.0” W x 14.25” D x 1.75” H
Weight: 7 lbs.
A manual or auto-s witching alternate IF input, la beled EAS input,
is provided for connection of an Emergency Alert System 44 MHz
IF signal. When the EAS IF signal appears at the EAS input, the
main video and audio modulated IF is replaced by the EAS input
signal.
The EAS/Alternate IF feature allows a choice between manual
and automatic selection of the EAS/ALT IF input signal. This
is done through a 3 position terminal strip on the rear of the unit.
In the manual mode the EAS/ALT IF feature is activated by a contact
closure switch, which completes a ground connection. In the
automatic mode, two positions on the terminal strip are jumpered
together enabling an automatic detection circuit in the unit. When an
EAS/ALT IF signal is routed to the EAS/ALT port the unit automatically
switches to that alternate signal.
MONO AUDIO
Connector: RCA-Type
Input Impedance: Greater than 10k ohms, unbalanced
Input Level: 0.5 to 4.0 volt Peak-to-Peak
Frequency Range: 50 Hz to 15 kHz
Frequency Response: ± 0.5 dB
Total Harmonic Distoron: 1% @ 25 kHz deviaon
Signal-to-Noise Raon: 59 dB
Over-modulaon Threshold: 25 ± 2 kHz peak deviaon
IF
Input/Output Connector: F-Type (Female)
Aural Frequency: 41.25 MHz
Visual Frequency: 45.75 MHz
COMPOSITE IF
Aural: +20 dBmV
Visual: +35 dBmV
Input/Output Impedance: 75 ohms
Input/Output Return Loss: 16/15 dB
EAS / ALTERNATIVE IF
Connector: F-Type (Female)
Input Level: +30 dBmV @ 45.75 MHz
Switch Isolaon: Greater than 60 dB
Loading...