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P. C. Electronics  2522 Paxson Lane  Arcadia  CA  91007-8537  USA            

©2013

Tel: 

1-626-447-4565

 m-th 8am-5:30pm pst 

(UTC - 8)

 

   Tom 

(W6ORG)

 & Mary Ann 

(WB6YSS)

Web site:  http://www.hamtv.com        Email:  ATVinfo @ hamtv.com

TX70-5s 70 CM ATV TRANSMITTER

USERS MANUAL

The TX70-5s transmitter is designed to provide >4Watts peak envelope power (sync tip) of video

modulated RF in the 70 CM (420-450 MHz) amateur band on any of 4 switch selected frequencies -
439.25, 434.0, 427.25 and 426.25 MHz - with a duty cycle of 15 minutes on and 5 off.  Longer key down
periods can be done at reduced power or by blowing air on the enclosure.

Any licensed Technician class or higher Radio Amateur may operate this transmitter in accordance

with 47 CFR  part 97 of the FCC Rules and Regulations.

The TX70-5s accepts U.S.A. standard composite video (1 volt pk-pk) from any source such as

color or black and white cameras with video output  or camcorders, VCR’s, or DVR’s for transmission.
Audio from these sources or a low impedance dynamic mic is also transmitted on the 4.5 MHz sound
subcarrier. Transmit / receive power and antenna switching is provided for a companion high sensitivitty
TVC-4s downconverter.  A cable ready TV may also be used to receive:  439.25 MHz equals cable
channel 60, 434 can be received on cable channel 59, and 427.25 or 426.25 received on cable channel
58.

PLEASE read through this manual before plugging in an cables and attempting operation.  Each

connector and control is described here to enable your proper hookup and operation.  Also the unique
video practices associated with ATV and the 70 CM band are described.  More information on ATV can
be found on our Application Notes web page at www.hamtv.com.

     1

Summary of Contents for TX70-5s

Page 1: ...ons The TX70 5s accepts U S A standard composite video 1 volt pk pk from any source such as color or black and white cameras with video output or camcorders VCR s or DVR s for transmission Audio from these sources or a low impedance dynamic mic is also transmitted on the 4 5 MHz sound subcarrier Transmit receive power and antenna switching is provided for a companion high sensitivitty TVC 4s downc...

Page 2: ...ownconverter DC power center is is at this jack when the XMIT REC switch is in REC and open when in XMIT 2 TX70 5s ATV Transmitter Quick Start Place the transmitter on a flat surface with no other objects within 2 inches This is important for convection cooling especially the right side during key down periods greater than 5 minutes the enclosure will become warm to the touch If key down periods w...

Page 3: ...NE AUDIO INPUT High level line audio usually from the same source as plugged into the companion Video input is plugged into this jack using another RCA phono plug shielded cable Minimum level is 1 v pk pk into a 10K load 75 OHMS TO MONITOR This output provides the composite video from the front panel Video jack during receive to enable you to aim the camera and to best adjust the focus and lightin...

Page 4: ... on 2 meters full duplex to comment on picture content etc Others listening to the 2 meter channel are often hooked into ATV this way You can also run full duplex audio and video with another station on 900 or 1200 MHz bands It is more fun as time goes on to have many hams put their families other hobbies and varied interests on the screen Let others know your 2 meterATV freq by publishing in loca...

Page 5: ... up your AGC on noise making you more susceptible to intermod and overload interference without improving the sensitivity Only changing to lower loss coax or adding a good quality 1dB NF preamp at the antenna will give you a little sensitivity improvement Monitoring yourself with a TV set to cable channel 58 59 or 60 in the same room can give erroneous results due to overload and multipath reflect...

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