1.3 GHz Wireless AV set – Summery

Here is a little summery about the following 1.3 GHz Wireless AV set:

1.3 GHz Wireless AV Set

I got mine from eBay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300405272136

The set was shipped with the following items shown on the next picture:

1.3GHz Wireless AV Set


Technical details:

  • Supply voltage 12V
  • Supply current 280mA
  • Output power >28.5dBm
  • Size 65x50x20mm
  • Weight (measured) 62g complete; bare PCB 10g
  • SMA antenna connector
  • 3.5mm 4 pin AV+power jack
  • Gain adjustable
  • One button control
  • 15 Channels


Transmitter FrontTransmitter TopTransmitter Bottom


Transmitter PCB TopTransmitter PCB Bottom

As you can see there is no extra shielding around the PCB. Heat dissipation is mainly done through the bottom side of the PCB.
Some details about the components:

  • Philips TSA5520 1.3 GHz universal bus-controlled TV synthesizer
  • Futjitsu FLU10 RF power amplifier
  • 24C02B EEPROM
  • uC marked JX903D ???

Interesting is the separate EEPROM. Obviously the channel and frequency configuration is stored inside. Seems that is the first transmitter with possibility to use customized frequencies. I need to find out 😉

The EEPROM is used only to store the selected channel. The channel will be read on power up and stored on new selection.

Channel Frequency [MHz] Power [dBm]
1 993 28.3
2 1020 28.4
3 1050 28.3
4 1060 28.2
5 1080 28.2
6 1100 28.0
7 1120 28.0
8 1140 28.2
9 1160 28.6
A 1180 28.7
B 1200 28.6
C 1220 28.3
D 1240 27.9
E 1256 27.6
F 1280 27.3

Harmonic Distortion:

1. 28.04 dBm @ 992.97 MHz
2. -13.51 dBc @ 1.99 GHz
3. -16.15 dBc @ 2.98 GHz


The receiver is similar to many others coming with such wireless AV sets. You have two buttons to control the receiver, one to cycle channels and a second to store channels for auto cycle.

1.3 GHz Wireless AV Receiver

A very interesting fact: The receiver is rated for the frequency range 0.9 – 1.56 GHz, split into 28 channels!

Channel Frequency [MHz]
1 921
2 993
3 1022
4 1051
5 1062
6 1081
7 1100
8 1120
9 1140
10 1160
11 1180
12 1200
13 1220
14 1240
15 1256
16 1280
17 1300
18 1320
19 1340
20 1360
21 1380
22 1400
23 1420
24 1440
25 1460
26 1480
27 1500
28 1520


1.3GHz Wireless AV Receiver

The quality of the PCB looks much better on this receiver than on others I have seen so far. A large spring washer keeps the tuner module in place 🙄 But it’s also the first one with separate video amplifier. By default the gain of the video amplifier is fixed. But there are pads to solder a potentiometer (2KOhm) to adjust video signal level. Very useful if you drive more than one video input in parallel from the receiver.
Some details about the components:

  • TA7176 IF Amplifier+FM  Detector
  • EEPROM 24C02B
  • Philips NE592D Video amplifier
  • uC without marking
  • 78M05 + 78M09 Linear voltage regulators

The tuner module is common standard but the RSSI output pin is missing. You need to solder one yourself, the PCB is already prepared. See picture below.

Level [dBm] 	RSSI [V]
-115		0,786
-110		0,784
-105		0,781
-100		0,771
-95		0,758
-90		0,789
-85		0,938
-83,5		1,000
-80		1,160
-75		1,382
-70		1,601
-65		1,810
-60		3,370
-55		3,570
-50		3,660
-45		3,710
-40		3,750
-35		3,790
-30		3,870
-29		3,940
-25		4,340
> -20		4,340

The tuner uses the common TA1322FN Down converter in combination with a TA8804F FM demodulator. A 27MHz SAW filter ECS-D479.5B is used in the tuner. (Should be replaced by a ECS-D480A with 17MHz)


No idea here. These antennas are usually crap so I will not test them for VSWR. Better stick with an Yagi and the Inverted-V.


With some rework this wireless AV set has a big potential for hacking and customizing.

Due to the fact that frequency configuration seems to be stored in EEPROM on both transmitter and receiver one can use almost any frequency within the RF specs of the devices. (For example not only one legal frequency at 1280MHz).

A separate shielding box needs to be made for the receiver. 65g for the original one is a way to much to carry up in the air. Also heat dissipation can be improved this way.

All in all I think that’s a good set, good hardware potential and better quality than I have seen before.

Channel RX Frequency
1 921
2 993
3 1022
4 1051
5 1062
6 1081
7 1100
8 1120
9 1140
10 1160
11 1180
12 1200
13 1220
14 1240
15 1256
16 1280
17 1300
18 1320
19 1340
20 1360
21 1380
22 1400
23 1420
24 1440
25 1460
26 1480
27 1500
28 1520
Auto 1540

24 thoughts on “1.3 GHz Wireless AV set – Summery

  1. Could you show where to get the RSSI?

    I have a similar 15ch unit from ebay. However, my transmitter has a blue board and a different IC near the SMA jack. Where yours is white, mine is nearly half the size and has the writing scratched out. I’ve been 500m with the included omni on channel f (15 rx).

    • To get the RSSI you need to modify the tuner module inside the receiver. On mine the pin is missing, but the board is prepared. So you just need to solder an extra pin. I have other tuner modules where the pin exists but is not used.
      See the post above for details.

  2. what method do you use to test RSSI voltage at different signal levels? How do you generate the different signal levels?

    • At work I have access to various RF test equipment.
      The RSSI voltage was measured generating a input signal with variable level using a RF signal generator connected to the receiver. The signal was FM modulated.

  3. Hi,
    I read with interest your research. I have a 4 channel version and it is very similar.

    My transmitter is a gold coloured unit claimed at 3W but I think is only 700mW. It does not draw enough power to be 3W and many of the component near the output are missing. It only has 4 channels.

    It uses the same 5520 IC as your tranmitter. You should be able to modify it the same as I have done. I modified it for 1249Mhz by cutting the track out of the PLL and wiring in a multi-turn potentiometer. The voltage out of the PLL controls the transmit frequency. By using a potentiometer I lose the accuracy of a PLL but I just fixed it on one frequency. I found in my transmitter:

    ChNo Pin10V Freq
    >> 6.882V=1.249GHz
    >> 6.6V =1.240GHz
    ch4 5.47V =1.20GHz
    ch3 4.34V =1.16GHz
    ch2 3.21V =1.120GHz
    ch1 2.07V =1.08GHz

    Far side of 513 resistor (on my unit) is best
    cut track on board going to pin10

    around 10k multi-turn to ground. So basically I measured the voltage at PIN 10 of 5520IC. I varied the transmit frequency using the channel switch. I noted the voltage value and the transmit frequency (I measured the frequency on a spectrum analyser) Then I cut the track at PIN 10. I connected a multi-turn potentiometer between the lead from pin 10 and ground. I rotated until the correct transmit frequency is found. The voltages I calculated helped me find the correct frequency fast.

    I believe to receive custom frequencies you would need to send I2C commands to the tuner IC. The datasheet for this has info but I have not tested anything. You would need something external to do this or else re-program the IC.

    There is plans for controllers for other tuners (comtech). The software might work OK or might need to be changed.

    Thank you for the RSSI information
    Please ask me any questions if you do not understand.


    • Regarding the receiver tuner I made already some progress. At least I know that controlling by I2C works well.
      I wrote a small PC code to control the tuner through a USB-I2C interface. This way you can set frequencies as accurate as 6.25KHz.

      Next plan is to replace the receivers micro-controller with an AVR to operate the tuner at customized frequencies. I have only one now which works at my favorite 1240MHz. But this one has interferences in the video signal coming somewhere from the internal amplifier.

      The second receiver can use only 4 channels but neither work on 1240MHz nor 1280MHz, here the AVR will jump in.

      Same would work for the transmitter. Replace the micro-controller with a customized one to control the PLL.

      By the way, reprogramming of the original controllers in TX and RX will not work, they are on-time-programmable versions.

      • My receiver I have is no good to me without control. It covers 1.08 to 1.24GHz. I would like to control 1.240 to 1.320GHz and also 900-2100Ghz for use with 10GHz downconverter LNB.

        I would like to help more people receive Amateur Television signals using cheap hardware. That is why I purchased the equipment.

        Single frequency transmit is not a problem for me but the receiver needs to work on at least one frequency that I need (1.276Ghz)

        Can u send me your software for I2C control and tell me which USB to I2C hardware it works with? I do not need finished code. I can modify it for my needs. Can I share this code with others?

        • Dan, I will do a short write-up and attach the code in a post (not possible in comments).

  4. I have downloaded the software and I have ordered the I2C USB hardware. Thank you very much!

    Sorry to keep asking questions 😉
    “By the way, reprogramming of the original controllers in TX and RX will not work, they are on-time-programmable versions”

    Can you tell me what type they are? Also is there an equivalent re-programmable AVR? I know you may have started this work already. I would like to try too!

    I would like to order one for testing.

    • At least in the 4 channel receiver the uC is a EM78P156ELM made by ELAN Microelectronics. All RX and TX I have seen so far uses ELAN controllers.

      An equivalent AVR doesn’t exist, pin-out is always different. But I’m going to use an ATtiny44 for my testing with the 4 channel receiver. Not started yet, only removed the original uC and wrote down the pin functions. So next will be a on-the-fly wiring with the tiny44 for software development.

    • Skew-Planar-Wheel on TX
      8-turn Helix on RX for long range, another Skew-Planar-Wheel for short range/area flights.

  5. Thanks for the great review. You dont happen to know the pin out of the 3.5mm 4 pin AV+power jack. I want to remove the jack and just solder my wires to the PCB but I am unsure of how to test the pins to see which is video, audio, power and grounds.

    I have a multimeter, so i might just poke around.

    Thanks for the help

    • Looking at the top of the PCB, antenna connector pointing to the right, AV+power jack on the lower left, counting left to right:

      * GND (far left on board edge)
      * Video
      * Audio
      * Power supply

  6. Great review.

    I have a similar vRX and I was wondering about something you said.
    I usually have different gear connected to it in parallel, the goggles, DV cam to record,…
    So I was wondering about the video amplifier, would you mind showing where that would


    • The amplifier is build-in. It’s the 8-pin SMD IC between the tuner connector and LED display. The gain is set with the resistor which is placed between this IC and the adjustable coil.

  7. Hi!
    I see you have the same av transmitter and receiver that I just bought used, so I hope you can help me.
    I didn’t get the 3,5mm 4 pin AV and power jack cable with the deal.
    So I am going to solder my own, but of course I don’t know in with order the cables go.
    Do you know or are you able to find out? It would help me a lot, and I would be most grateful.
    I think they go like this:
    3,5mm tip is red, first ring is yellow, second ring is black and the shield is white, is this right?
    Thanks /David.

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