HDMI Modulator | QAM RF Coax Output - Full HD up to 1080P - 1,4,8 Channel

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Description Features Drawings Video Model Selection Specification Q&A Documents Support
4 HDMI model description
Thor 4 HDMI Digital RF Modulator is an all-in-one device integrating MPEG2 encoding and modulating to convert audio video signals into DVB-C T ATSC ISDB-T RF out.

H- THUNDER-4 Supports 4 HDMI inputs and its modular design (maximum 4 HDMI inputs) and flexible configuration makes it scalable and very reliable while providing high performance.

The signal source could be from any STB, satellite receiver, closed-circuit television cameras, and antenna, etc. Its output signal is designed to work with any TV or STB. Because it comes standard with every RF modulation standard builtin, this device can work anywhere in the world in a plug and play format. 

This unit is similar to our popular line H-1,2,4 HDMI-QAM-IPLL product line, but it has some differences. It is a less expensive unit, each program is modulated on its own frequency, CATV RF output only, no IPTV output 





Number of Inputs 1,2,4,8    1,2,4
Number of CATV frequencies (carriers) 1,2,4,8 - Each video has its own channel 4
Modulation QAM, ATSC, DVB-T, ISDB-T in the same unit -pre-loaded & switchable                        QAM, ATSC, DVB-T, ISDB-T Firmware dependent
Can modulate multiple programs on the same frequency - carrier           


each program needs to be modulated on a separate frequency 


multiple programs can be modulated on the same frequency, for example, 2.1, 2.2, 2.3, 2.4 

Encoding method MPEG2 only MPEG2 or H.264 - selectable
Dolby Audio Encoding Yes Yes
Front Panel Control YES YES



  • 4 HDMI channels Inputs (model dependent)
  • HDCP compliant works with any HDMI source like DVD Player or Cable, Satellite STB up to 1080p/60 resolution
  • MPEG2 Video Encoding
  • 1080p/60, 1080i, 720p, 576i, 480i Video Resolution
  • Low Latency (50~100ms)
  • MPEG layer 2, AAC, and DD AC3 Audio Encoding
  • LCN
  • DVB-C DIGITAL QAM, ATSC, DVB-T, ISDB-T RF in one device, Modulation dynamic switching
  • Control Via Web-Based NMS, and easy updates Via Web
  • LCD Display and front panel control

Economical 4 HDMI Digital Modulator RF CATV over Coax QAM ATSC DVB T ISDBT Included Thor B
This video shows some of the detailed functionality of the new Thor 4 channel digital modulator in full HD. The Thor Thunder-4 modulator is the easiest way to distribute HD content to an unlimited amount of TV's or monitors using an existing coaxial RF network. This modulator is unique because it can produce 4 separate CATV channels in any RF modulation format simultaneously, those channels can be set individually and do not have to be adjacent, so you can set it up on channels 10/21/32/45 without any issue. It supports ATSC, QAM Annex B and A, DVB-T, and ISDB-T. One modulator can distribute Video to unlimited TV's using RF amplifiers, taps, splitters etc so long as your RF network supports it. The Thunder-4 is HDCP compliant and supports, VCT -Virtual channel numbers and names. Supports SD and HD video resolutions : 480i,720p,1080iand 1080p/60hz input resolution. By far the best value for a 4 channel modulator with accessible built-in options, warranty, and Thor Support to help make sure your project or application installation goes perfectly the first time. Link to detailed specifications : https://thorbroadcast.com/product/1-4-8-hdmi-digital-rf-encoder-modulator-full-hd-up-8230.html/238
Unboxing HDMI modulator HD 4 Video Audio to Coax up to 1080p QAM, ATSC, DVB-T ISDB-T ANNEX B A
The best 4 channel HDMI modulator. This video describes the most cost-effective solution for 4 channel HDMI modulator H-THUNDER-4 Made by Thor Broadcast in Torrance California. Unit works as a 4 channel HDMI encoder modulator, contains 4 independent HDMI inputs, and coax CATV RF output. It supports 5 different modulation standards DVB-C QAM Annex A and Annex B, QAM 256 and QAM 64, ATSC, DVB-T, ISDB-T. Any of the 4 channels can be set separately and it could be spread out across 54 to 1000Mhz. The VCT - Virtual channel number supported as well. This is link to the specifications : https://thorbroadcast.com/product/1-4-or-8-hdmi-digital-rf-encoder-modulator-8230.html/238
8 HDMI Sources To 1 Cable | Thor Broadcast Thunder 8 RF Encoder Modulator
1, 4, or 8 HDMI Digital RF Encoder Modulator - Full HD up to 1080P Thor 8 HDMI Digital RF Modulator CC is an all-in-one device integrating MPEG2 encoding and modulating to convert audio video signals into DVB-C T ATSC ISDB-T RF out. https://thorbroadcast.com/products/hdmi 0:00 Unboxing Intro 1:25 Front pannel IP adress set up 2:46 Video Sources 3:37 Splitter 4:02 Hdmi Ports and Video Sources 4:32 Thor Brodcast Website 5:19 How to access the web interface with a browser 6:04 Encoder & Modulator settings 8:07 Status 9:00 Encode 10:16 Network Settings 10:34 Password 10:50 Update firmware 11:22 The Encoder will auto detect your source resolution (720p 1080P etc) 12:01 How to change the name of a Channel 12:21 Tuning the ATSC channels with a HD Home Run Tuner If these Videos help you please consider supporting my work https://www.paypal.com/donate/?cmd=_s-xclick&hosted_button_id=4CRW8P29AA6PY https://www.patreon.com/RobbieStrike Learn about Satellite and other things by sitting back and binging on these playlists https://www.youtube.com/user/ottawaoctane/playlists https://www.youtube.com/user/ottawaoctane/videos https://www.facebook.com/RobbieStrikeVideos/ https://twitter.com/robbiestrike3 (c) Robbie Strike 2023 http://www.RobbieStrike.com www.FreeSatelliteTV.net my links https://flow.page/robbiestrike Thor Broadcast has sent me this product to review free of charge. But for most people they would be happy for home use the once channel unit like this the thor Petite https://www.youtube.com/watch?v=C17OgxnjLeo&pp=ygUTcm9iYmllIHN0cmlrZSB0aG9yIA%3D%3D There is a one channel device that does this. $495 https://ebay.us/U9Xcw9
Quick configuration Guide for H-THUNDER-4 - 4 HDMI Digital RF Encoder Modulator- Full HD up to 1080P
Thor 4 HDMI Digital RF Modulator is an all-in-one device integrating MPEG2 encoding and modulating to convert audio video signals into DVB-C T ATSC ISDB-T RF out. H- THUNDER-4 Supports 4 HDMI inputs and its modular design (maximum 4 HDMI inputs) and flexible configuration makes it scalable and very reliable while providing high performance. The signal source could be from any STB, satellite receiver, closed-circuit television cameras, and antenna, etc. Its output signal is designed to work with any TV or STB. Because it comes standard with every RF modulation standard builtin, this device can work anywhere in the world in a plug and play format. This unit is similar to our popular line H-1,2,4 HDMI-QAM-IPLL product line, but it has some differences. It is a less expensive unit, each program is modulated on its own frequency, CATV RF output only, no IPTV output Features - 4 HDMI channels Inputs (model dependent) - HDCP compliant works with any HDMI source like DVD Player or Cable, Satellite STB up to 1080p/60 resolution - MPEG2 Video Encoding - 1080p/60, 1080i, 720p, 576i, 480i Video Resolution - Low Latency (50~100ms) - MPEG layer 2, AAC, and DD AC3 Audio Encoding - LCN - DVB-C DIGITAL QAM, ATSC, DVB-T, ISDB-T RF in one device, Modulation dynamic switching - Control Via Web-Based NMS, and easy updates Via Web - LCD Display and front panel control
Quick configuration Guide for H-THUNDER-8 - 8 HDMI Digital RF Encoder Modulator- Full HD up to 1080P
Thor 8 HDMI Digital RF Modulator CC is an all-in-one device integrating MPEG2 encoding and modulating to convert audio video signals into DVB-C T ATSC ISDB-T RF out. H- THUNDER- Supports up to 8 HDMI inputs and its modular design (maximum 8 HDMI inputs) and flexible configuration makes it scalable and very reliable while providing high performance. The signal source could be from any STB, satellite receiver, closed-circuit television camera, and antenna, etc. Its output signal is designed to work with any TV or STB. Because it comes standard with every RF modulation standard built in, this device can work anywhere in the world in a plug-and-play format. This unit is similar to our popular line H-1,2,4 HDMI-QAM-IPLL product line, but it has some differences.It is a less expensive unit, each program is modulated on its own frequency, CATV RF output only, with no IPTV output The 8-channel model has 8 HDMI / CVBS -baseband video inputs that can be selected from the menu, so support any HD HDMI source or any analog CVBS source like Analog Video cameras. This Input can be also used as Input for Closed captioning generated from video devices like DVD players or Cable STB's on CVBS output CC 21 Features - 1-8 HDMI channels Inputs (model dependent) - 8 Ch CVBS input (H-Thunder-8 only) - HDCP compliant works with any HDMI source like DVD Player or Cable, Satellite STB up to 1080p/60 resolution - MPEG2 Video Encoding - 1080p/60, 1080i, 720p, 576i, 480i Video Resolution - Low Latency (50~100ms) - MPEG layer 2, AAC, and DD AC3 Audio Encoding - CC (Closed Caption), EIA 608 - LCN - DVB-C DIGITAL QAM, ATSC, DVB-T, ISDB-T RF in one device, Modulation dynamic switching - Control Via Web-Based NMS, and easy updates Via Web - LCD Display and front panel control
Model Selection

Unboxing New 4 Channel modulator H-THUNDER-4



HDMI Encoding Section



  • H-THUNDER-1 - 1HDMI + 1CVBS for CC
  • H-THUNDER-8 - 8HDMI + 8CVBS for CC







[email protected]/60i








[email protected]/60i




[email protected]/60p



2.000~20.000 Mbps

Rate Control


Aspect Ratio

16 :9



MPEGI layer2, AAC, AC3

Sample rate



Bit rate

MPEG1 layer2 (192kbps)




AC3 (128kbps)

DVB-C Modulator Section


J.83A (DVB-C), J.83B



RF frequency

100-1000MHz, 1KHz step

RF output level

-63~ -16dBm (44~91 dBµV), 1dB step

Symbol rate

3.000~7.000Msps adjustable






64/ 256QAM




DVB-T Modulator Section




2M, 3M, 4M, 5M, 6M, 7M, 8M



Code rate

1/2, 2/3, 3/4, 5/6, 7/8

Guard Interval

1/32, 1/16, 1/8, 1/4

Transmission Mode:

2K, 8K



RF frequency

100-1000MHz, 1KHz step

RF output level

-63~ -16dBm(44~91 dBµV), 1dB step

ISDB Modulator Section





Guard Interval

1/32, 1/16, 1/8, 1/4

Transmission Mode

2K, 4K, 8K

Code rate

1/2, 2/3, 3/4, 5/6, 7/8

RF frequency

100~1000MHz, 1KHz step

RF output level

-63~ -16dBm(44~91 dBµV), 1dB step

ATSC Modulator Section





RF output level

-63~-16dBm (44~91dBµV),1dB step



RF frequency

100~1000MHz, 1KHz step

RF output level

-63~ -16dBm(44~91 dBµV), 1dB step







Web update


Power supply

AC 100V±10%, 50/60Hz or AC 220V±10%, 50/60Hz


482x328x44.5mm = (19"x12.9"x1.7" )



Question and Answers
No, the 4channel HDMI modulator H-THUNDER-4 has separate Channels for each input but it can be any channel, for example, 2,20,50 99, there is control of each individual channel. Do you need to Multiplex (MUX) all 4 TS programs on one physical frequency (One RF 6Mhz channel)? QAM 236 contains 38Mps data, so you can multiplex 4 programs encoded at 9Mbps each or 8 programs encoded at 4.5Mbps We have different 4 or 12channel unit available https://thorbroadcast.com/product/4-hdmi-component-hd-to-coax-and-iptv-hd-8230.html/21 https://thorbroadcast.com/product/catv-rf-modulator-hdmi-multiplexer.html/37
Yes, I just checked online, the Tivo has ATSC tuner, The modulator sends QAM or ATSC, it is selectable, it will be compatible with a Tivo
The best way to convert 28 HDMI / SDI to QAM would be using H-HYBRID-RF-8 Modulator, it has 8 independent switchable SDI / HDMI inputs : https://thorbroadcast.com/product/8-channel-hdmi-and-sdi-clear-catv-rf-modulator-qam-8230.html For optical RF coax over a fiber we recommend to use the following devices : Fiber OTx https://thorbroadcast.com/product/32-mw-catv-rf-over-fiber-tx-45-870-mhz.html Fiber Rx Rack https://thorbroadcast.com/product/catv-rf-fiber-receiver-high-rf-power-rack-8230.html F-PLC-1x8 https://thorbroadcast.com/product/1-x-2-to-1-x-128-fiber-optic-couplers.html/226 The main thing I want to point out is that these are all 1310nm; will only work in the CATV band 45-870Mhz for QAM 256 If you are sending L-band (which is satellite TV) in the band 1400-2800Mhz I'm somewhat familiar with the Foxcom stuff, but I just checked the specs on their unit, it uses 1510-1610nm wavelength; so this would not be compatible. If you have different information then what I just read online then please let me know. We have similar, more sophisticated L-band gear https://thorbroadcast.com/product/6-ch-l-band-over-single-fiber-extender-54-3000mhz-cwdm.html And ours is not compatible with the lower band RF CATV gear because they operate in different bands, furthermore, you can not connect a CWDM receiver, like ours or Foxcoms, to a fiber link that is using a single laser, in the different wavelengths. Please give me a call if you'd like to discuss, if you'd like a BOM for the equipment above for a distribution system for point to multipoint let me know.
Is the system QAM?
its Cox cable in Omaha, NE. I just know its HRC
Ok, and are there available channels you can use to insert into?
We need to verify, may need to delete a channel
I see
for now, just need 1 channel
Okay, well any of our Modulators will work, we have 1 Channel units that are compact, some are rack mount; they vary by chipset and various abilities
Will this be some sort of application like digital signage or will you play movies? Live Events etc?
digital signage type
Okay, then you can really go with any model and you'll be fine.
i see. does Thor have a channel delete item?
That's a bit more complex because you need an RF filter
so you'd have to specify which channel, and we make a frequency filter that would block the preceding program on that channel
ok. I know in the old days you needed to stay 2 channels away, but that was analog. is digital different?
I haven't seen a project come through that required such a device in a long while, but yes they still tell you to block out an extra channel on each side.
However I can have our engineers look into that for you to see what they can do
ahh, ok. can you send me some model numbers, non rack mount for now that i can look at?
just the modulator for now
looks good. is HRC and QAM same thing?
That unit is similar but also includes closed captions
ok, nice
so HRC and QAM vary by one thing, and that's starting on channel one or channel two
however, both use 6mhz stepping in frequency modulation
i see
so reasonably speaking, so long as you don't use channel one; then any QAM product should work for you
Because when we discuss modulation, the biggest thing is the Standard, which is cable to ATSC
you have cable
but I'm looking to be able to change cable channel from any of the TVs
I know all the tvs will show the same program, but I would like to be able to change the channel from any of them
do you have anything that would do the trick?
we have modulators that can create your own channel from any HDMI source
so if the cable box is set to ESPN and you create it on channel 30
all the TV's in the house on channel 30 will see ESPN
But there is no way to change the channel from the cable box, without using a remote facing at the cable box
In order to do that you would need IR devices
ok, how hard is to install IR devices?
that would be up to the manufacturer spec
we do not offer those kinds of units
We only IR with HDMI over Fiber
what kind of fiber?
it is pre-terminated cable or can I use commercial fiber cable?
You would have to buy the fiber separately
LOL I do work with fiber cable, cool
those units are really simple to use, plug and play
but this is an extender only right? I don't see how can I connect multiple TVs
you'd have to send them individually
or you can use a modulator
and then buy separate IR products
ok, I have the cable box HDMI output right connected to what product? and from there to each tv with the extender
each TV can receive COAX cable instead of fiber
RF output on each of the 8 RF channels can be individually set to a frequency and modulation standard (2 on QAM, 3 on ATSC, 4 on ISDBT, etc) - YES
Do you mean the modulator supports up to eight RF channel? -YES
And each of the 8 RF channels could carry the corresponding SDI input sources?- YES
We need digital modulation - THIS IS DIGITAL MODULATOR
We have other models 1-12channel, but there are more expensive because they also have IPTV outputs besides modulated RF output
Prices as follow
1 SDI modulator, H-1SDI-QAM-IPLL
2 SDI modulator H-2SDI-QAM-IPLL 
4 SDI modulator H-4SDI-QAM-IPLL
12 SDI modulator H-12SDI-QAM-IPLL
So, it is possible but if it is not straight forward, it has to be done in a few steps.
They can set up a streaming channel on Youtube, they can stream to youtube form the cell phone then use IP STB to receive this youtube stream and output as an HDMI, the HDMI would be connected to the modulator.
The video might be delayed about 5 seconds this way.
This is the link to the IP STB:
The other way would be to dedicate 1 cell phone and equip it with direct HDMI output then streaming would be not necessary, but maybe a dedicated PC would be more reliable and convenient.
All of our HDMI modulators can be found at that link, we have a few higher-end options and lower-end options
if you require rackmount, the least expensive One HDMI input modulator is this one
We have less expensive units in a compact format
I totally understand your application, the main questions are:
What is the encoded format for your multicast streams? MPEG2 or H.264.
Since your Tuner and also most TV's tuners support MPEG2 only, that would determine if we can use IP to QAM Modulator.
This is a link to H-IPRF-16QAM IP to 16 QAM Modulator
If your multicast streams are encoded in H.264, we would need to take a different approach,
We would need to decode those streams to HDMI using IP HDMI STB's then use our 2 x 8l HDMI QAM modulators H-HDCAOX-8.
This is a link to IP STB with HDMI  H-STB-IP
This is the link to 8ch HDMI modulator  H-HDCOAX-8
I attached the frequency chart for you, CATV RF QAM 139 physical channels,1979 is a Virtual channel, that means that comcast needs it to be on a virtual channel. Our unit supports that function. 
Each situation might be slightly different, we would need to program it and match the cable tv requirements, Customer would need to contact comcast and ask them following questions:

What is the frequency they require to modulate?
Do they require VCT, if so:
What is the VCT, major and minor channel?
What is a Service ID?
What is the Video and PCR  PID? do they need to be the same or different PID's
What QAM ? QAM 64 or QAM 256??
Do they allow HD resolution like 720p/1080i? , ( some companies like
Comcast allow only 480i SD resolution on Some STB's)

If you have some Cable TV  technician or engineer or Headend contact
information, you can forward it to us, we can try to find out for you
Once we get the answers we can preset the unit or help them set it up remotely.

So if you do not have Coax at that one TV, do you have any other
cabling that goes there?

Maybe Ethernet Cable RJ45?
Then you can use this

If you have Singlmode Fiber, you can use this

You could ultimately use something like this
But the range is very short, if there are other TV's nearby there will
be a delay in signal as well.
Wireless solutions are only good for direct line of sight as well.


Thanks for reaching out.
Do you have TV's have built-in IP Decoders?
If not how do you plan on decoding the IP streams?
How many HDMI sources do you have?
How many channels would you like to make?
Where are the sources coming from?
Do you have CATV service that is being delivered via cable or STB to your hotel?

Also do you need MPEG2 or H264?
We have some encoders here that will work

We also have decoders here



Generally speaking no television sold over the counter would have this feature.
Did you go through an integrator or purchase through a vendor that
supplies its own Hotel software like Sonifi Solutions?

What country are you in?
Will you need MPEG2 or H264?

We can do the HDMI to IP, and certainly the IP to QAM; do you have the
available LAN in your hotel?
At what point would you want to do the IP to QAM conversion? Every
Floor? Or are there multiple sections of the hotel?

The more information you can give us the better


An HDMI encoder modulator is a device that converts an HDMI signal into a digital format that can be transmitted over a Coax cable network or broadcast over the air. This allows users to distribute high-quality video and audio signals to multiple devices or locations using a single HDMI source. HDMI encoder modulators are commonly used in commercial and residential settings to distribute content from cable or satellite boxes, video game consoles, or other HDMI-enabled devices to TVs or other display devices.


An 8ch HDMI modulator ATSC QAM is a device that allows for the conversion of HDMI signals into a format that can be transmitted over a cable television network. This is useful for a variety of applications, such as distributing content from a set-top box, streaming device, or another HDMI source to multiple TVs or displays without the need for additional HDMI cables.

The modulator is designed to support eight HDMI channels, which means it can handle eight separate HDMI sources at the same time. This allows users to easily distribute content from multiple devices to multiple TVs, making it a great solution for multi-room installations or larger installations such as hotels, hospitals, and schools.

The modulator uses the ATSC and QAM standards to encode and transmit the HDMI signals over a cable network. ATSC is a digital television broadcasting standard used in North America, while QAM is a digital signal modulation method used in cable television systems. Both of these standards provide high-quality, reliable transmission of digital signals, ensuring that the content is delivered to the TVs or displays with minimal degradation or interference.

In addition to supporting multiple HDMI channels and using ATSC and QAM for transmission, the 8ch HDMI modulator also offers a range of other useful features. For example, it may include built-in signal processing and equalization to ensure the best possible signal quality, as well as support for various output frequencies to ensure compatibility with different cable networks.

Overall, an 8ch HDMI modulator ATSC QAM is a versatile and useful device that allows users to easily distribute HDMI content over a cable network. It is well-suited for a variety of applications, from multi-room installations to larger commercial installations, and offers a range of features to ensure high-quality, reliable transmission of digital signals.

n addition to its ability to distribute HDMI content over a cable network, an 8ch HDMI modulator ATSC QAM can also provide a number of other benefits. For example, it allows users to easily share content from a single HDMI source with multiple TVs or displays, without the need for additional cables or connections. This can save time and hassle when setting up a home theater system or other multi-room audio-visual installation.

Another benefit of using an 8ch HDMI modulator ATSC QAM is its ability to support multiple HDMI channels. This means that users can connect multiple HDMI sources to the modulator and distribute the content to multiple TVs or displays. This is particularly useful in situations where multiple users want to watch different content on different TVs, such as in a hotel or a school.

In addition to its practical benefits, an 8ch HDMI modulator ATSC QAM can also provide a more aesthetic and organized solution for home theater installations. By eliminating the need for multiple HDMI cables running from a single source to multiple TVs, the modulator can help reduce clutter and improve the overall look of the installation.

In conclusion, an 8ch HDMI modulator ATSC QAM is a valuable and versatile device that can provide a range of benefits for users who want to distribute HDMI content over a cable network. Whether used in a home theater system, a multi-room installation, or a larger commercial installation, the modulator can help ensure high-quality, reliable transmission of digital signals, and provide a more organized and aesthetically pleasing solution. It Can

can also be useful in commercial settings. For example, it can be used to distribute content from a set-top box, streaming device, or other HDMI source to multiple TVs or displays in a hotel, hospital, or school.

In a hotel setting, the modulator can be used to distribute content from a single HDMI source, such as a cable box or streaming device, to multiple TVs in guest rooms. This allows guests to easily access a variety of content without the need for additional cables or connections.

In a hospital, the modulator can be used to distribute content from a single HDMI source, such as a satellite receiver or streaming device, to multiple TVs in patient rooms, waiting for areas, or other public spaces. This can provide patients and visitors with access to a range of entertainment and information options.

In a school, the modulator can be used to distribute content from a single HDMI source, such as a computer or streaming device, to multiple TVs in classrooms, libraries, or other common areas. This can allow teachers and students to easily access educational content, presentations, and other materials.

Overall, an 8ch HDMI modulator ATSC QAM can be a useful tool in commercial settings, providing a convenient and reliable way to distribute HDMI content to multiple TVs or displays without the need for additional cables or connections.


ATSC (Advanced Television Systems Committee) and QAM (quadrature amplitude modulation) are both digital modulation techniques used to transmit television signals.

ATSC is a digital television standard used in North America, South Korea, and other countries. It uses 8VSB (vestigial sideband) modulation to transmit digital television signals over the air or through cable. ATSC is a high-definition (HD) television standard, and is capable of transmitting video, audio, and other data using a single 6 MHz channel.

QAM is a digital television standard used in cable television systems. It uses quadrature amplitude modulation to transmit digital television signals over coaxial cables. QAM is capable of transmitting multiple channels of video, audio, and other data over a single coaxial cable.

To convert HDMI (High-Definition Multimedia Interface) to coax using an encoder modulator, you will need an HDMI to coax encoder modulator. This device converts an HDMI signal into a coaxial cable signal that can be transmitted over a coaxial cable.

To use an HDMI to coax encoder modulator, you will need to connect the HDMI source (such as a DVD player or cable box) to the encoder modulator using an HDMI cable. The encoder modulator will then convert the HDMI signal into a coaxial cable signal that can be transmitted over a coaxial cable.

There are several types of HDMI to coax encoder modulators available, including both analog and digital modulators. The choice of modulator will depend on the specific requirements of the application, including the distance that the signal needs to be transmitted and the data rate of the signal.

It is also important to note that HDMI and coaxial cable signals are not interchangeable, and a device is required to convert between the two formats. An HDMI to coax encoder modulator is used to convert HDMI signals into coaxial cable signals, while a coaxial to HDMI decoder is used to convert coaxial cable signals back into HDMI signals.


There are many factors to consider when choosing the best HDMI
encoder modulator for your application. Some of the key factors to
consider include:

Compatibility: Make sure the HDMI encoder modulator is compatible with
the HDMI source and the destination device. Thor encoder modulators prefer
1280 x 720p 59.94/60 or 1920 x 1080i/p 59.94/60 resolution and frame rate.

Data rate: Consider the data rate of your network or setup to make sure you
get the maximum potential out of your equipment.

Distance: Consider the distance that the HDMI signal needs to be
transmitted, and choose the method of output that is most suited for your run.
Some of Thor's devices have multiple output capabilities.

Quality: Look for an HDMI encoder modulator that delivers high-quality
video and audio.

Features: Consider any additional features that you may need, such as
the ability to transmit multiple HDMI signals on the same 6mHz band,
high capacity devices (24 channel Performux Encoder), support for HDCP
(High-bandwidth Digital Content Protection), and support for audio
formats such as Dolby Digital (AC3).

Our best and cost efective  4 or 8 channels HDMI modulatrs are H-Thunbder-4 and H-Thunder-8 .

We do have also 8ch HDMI or 8 HD SD SDI - selectable  modulators avaiable H-Hybryde-RF-8

  1. The Petti modulator outputs a relatively low RF signal, so you may need to use an RF amplifier or a stronger, more commercial type of modulator.


40dB RF amplifier

HDMI RF comercial modulator :

As far as HDMI over LAN is concerned, it's easy to achieve using UDP multicast, and we have a very good almost plug and play solution for it.

For example, you could use the

TX side ) H-Spartan-2 HDMI to IP encoder: https://thorbroadcast.com/product/2-channel-3g-sdi-hdmi-h-264-ip-video-streaming-encoder.html

RX side ) You could use an IPTV STB for IP to HDMI conversion: https://thorbroadcast.com/product/compact-ip-decoder-set-top-box.html


If you want to send HDMI over WAN, you can use the same solution and stream the video as HLS. However, this requires good network and streaming knowledge, and it's not plug and play. Specific setup is required, including access and setup of the router.

If you move encoder or decoder to different places, the devices must be reconfigured

Please let me know if this is clear

We have done quite a bit of business on such ships and seafaring vessels; in this particular case it would be helpful to know how many HDMI and how many SDI inputs you require. 
We have quite a few options to choose from in full HD modulation, in this particular case I would urge you to take a look at this product that might be a perfect fit for your needs. 
This model has 8 HDMI inputs and 8 SDI inputs; the total capacity is 8 outputs so you can pick and choose how you want to split up those 8 inputs between HDMI and SDI. 
This flexibility along with the built in modulation standards make this a universal device ready to deploy anywhere in the world. 

The modulator we were working on was set to the ATSC modulation standard, so I switched it to QAM.

It looks like the particular TV didn't support the CVCT virtual channel number standard; it was reading physical channel numbers and TS ID.

This is why we needed to adjust it. You will not have that issue often because the majority of TVs will support CVCT.

If you are using multiple devices and combining them together, all modulators must be set to QAM, and QAM channels cannot be repeated on any of the modulators.

Also, they need to be merged with similar +/- 5dB RF power.

I would suggest getting a good CATV RF meter/analyzer; it would simplify the installation process.

You would be able to see the carriers and determine if the levels are correct.

The easiest way to test the system is to take measurements directly after the combiner and do the scan there.

 If you can see all the channels, the rest is proper RF distribution.

Please note that most TVs are able to display channels at +25dBmv to 0 dBmV.

The RF amplifiers used in the system cannot receive an RF signal greater than +12dBmV.

You can always count on our technical support. We will always help to determine any issues

Yes, we do have UDP multicast IP to 16 or 32 QAM gateways available, in stock.
This is the link:

  • What is the total number of streams that you need to modulate?
  • Are the streams encoded in MPEG2 or H.264?

Are there cameras located on the LAN network or WAN network (public internet)?

Do they have the ability to output UDP multicast streams?

If your camera operates on the LAN (internal network) and is able to output UDP multicast, then we have a perfect solution.

The H-IPRF-16ATSC is an IP (UDP multicast) to 16 ATSC channels and IP-UDP output gateway.

 Please note that this is a gateway, so H.264 streams will not be changed to MPEG2. The modulator will carry H.264, so not all TVs may support that.

Link: https://thorbroadcast.com/product/iptv-to-16-32-clear-channel-rf-qam-atsc-modulator.html/124

If your cameras are located on the WAN and stream with a different protocol than UDP multicast, then the only way would be to:

1) - Decode each stream to HDMI 



2) - Use ATSC modulators

For the ATSC modulators, you can use either the H-THUNDER-8 (8 HDMI to ATSC with no IP out) or H-4ADHD-ATSC-IPLL (4ch HDMI to ATSC and IP out). We could do it as a two-stage process.


H-4ADHD-ATSC-IPLL: https://thorbroadcast.com/product/4-hdmi-component-hd-to-coax-and-iptv-hd-8230.html/22


The main question is, does the CVBS output from the STB carry CC on line 21?

 It is relatively easy to confirm.

You can take the RCA yellow CVBS signal from the STB and connect it directly to the TV.

If you can use the remote control to turn CC on/off and see the closed captions displayed, then the CVBS carries CC on line 21. If not, then it doesn't carry CC.


We need this CC data from line 21 to encode it into the RF channel. It is essential to have a CC source in order to pass it to the RF output.

Having a CC source is a prerequisite for us to proceed with encoding it into the RF channel.

It doesn't matter whether the CC is in French or English; what's important to us is whether CC is present or not.

Could you please perform this test and let me know the results? It should confirm whether the CVBS output carries CC on line 21.

This is how it works :
The Closed Captioning (CC) data is sent on the analog CVBS (Composite Video Blanking and Sync) signal on line 21.

Line 21 of the analog video signal is specifically designated for carrying the CC information.

In the NTSC video standard, which is commonly used in the US and Canada, line 21 of the analog video signal is reserved for additional data transmission, including Closed Captioning.

The CC data is embedded within the vertical blanking interval (VBI) of the video signal, which is the non-visible part of the video signal between the frames.

The CC data is encoded using specific protocols and standards, such as the EIA-608 standard for analog closed captions.

This encoded data is then transmitted on line 21 of the analog CVBS signal




Your application is very straightforward, and we can provide all the necessary equipment from the beginning to the end

Equipment needed in OBTCR
H-HYBRIDE-RF-8  8 SDI to 8 CATV RF QAM Channels Modulator
F-RF-TX-16  CATV RF fiber optic transmitter
F-PLC-1x8  1x8 fiber optic splitter
Remote locations will have optical receivers
Thor Fiber Optical Mini FTTH RF CATV CABLE TV Receiver with Dual Coax Output
or rack mountable  receiver  - Fiver to RF -
CATV RF Fiber Receiver - High RF power - Rack Mountable
Additionally we can make it easy to transport 8 SD/HD/3G -SDI from the  broadcast compound  to  OBTCR using only one fiber optic cable


Please review let me know if this is clear and if you have any questions.

The HDMI video audio signal doesn't carry closed captioning data. You would need to turn on CC on the HDMI source, and then the CC will be part of the video. 

However, you will not be able to control it at the TV level because the CC will always be present as part of the visible video.

Another option would be to use a digital modulator. 

We have digital HDMI modulators like H-Thunder-8, which has a separate CVBS (baseband video input) as a CC source (yellow RCA cable).

 The CVBS video always carries CC data on the invisible horizontal line 21.

 So, two different cables need to be connected to the modulator - HDMI as the video/audio source and CVBS as the CC source. 

This way, we will encode CC as a separate data, and you will have CC control at the TV level.

Absolutely you can use the rackmount Petit system. 
You should absolutely take a look at the accessories you'll need to go with that. 
The Rackmount Power Supply
RF Combiner (you might already have one of these)
Or you can go with a model that has higher density, this is one of our most popular options:
The Thunder-8
Enough room for 8 HDMI inputs and CC inputs if you need them. 
If you are looking to expand into simultaneous RF CATV with the potential of adding IPTV then this would be the best option

The CATV circuits operate in a 75Ω environment. Most RF laboratories
equipped with standard test instruments employ 50Ω as the
standard interface impedance.
In this application note, it will be shown that:
dBmV = 46.9897 + dBm50Ω
dBmV = 48.7506 + dBm75Ω
dBμV = 60 + dBmV
dBμV = 106.98 + dBm50Ω
dBμV = 108.75 + dBm75Ω
dBmV and dBμV
Most CATV measurements are referenced to voltage and measured in dBmV or dBμV. In the classic
definition, dBmV is referenced to 1mVRMS and output voltage (VOUT ) is measured in mVRMS (Equation


We do have 16-channel HDMI analog NTSC modulators, but I would not recommend them for you because they are SD, and the video quality is like cable TV from the 80s. These are needed only in specific applications where customers have old analog tube TVs. So currently, the 8-channel HDMI is the most advanced modulator we have.


There is another way to do it if you would have 24-135 channels to modulate. 

It is more complex; we can encode HDMI to IP streams using a 24-channel HDMI IP encoder, then use a separate IP to QAM gateway. 




But I would not recommend it for less than 24 channels.


Please chek the table below :

Frequency MHz RG-59 dB/100 Ft. RG-59 dB/100 M. RG-6 dB/100 Ft. RG-6 dB/100 M. RG-11 dB/100 Ft. RG-11 dB/100 M.
5 0.89 2.92 0.69 2.26 0.38 1.25
55 1.95 6.4 1.6 5.25 0.97 3.18
211 3.59 11.78 2.87 9.41 1.81 5.94
450 5.3 17.38 4.26 13.97 2.65 8.69
550 5.9 19.35 4.71 15.45 2.94 9.64
750 6.96 22.83 5.59 18.34 3.44 11.28
870 7.54 24.73 6 19.68 3.84 12.6
1000 8.09 26.54 6.54 21.45 4.23 13.87
1450 10.54 34.57 8.3 27.22 5.07 16.63
2250 13.7 44.94 10.6 34.77 6.5 21.32
3000 15.5 50.84 11.9 39.03 7.28 23.96
3500 16.74 54.91 12.85 42.15 8.28 27.16


The loss in a coaxial cable refers to the attenuation of signal strength as it travels through the cable. This loss is indeed influenced by the frequency of the signal, including CATV (Cable Television) RF (Radio Frequency) frequencies. Here's a more detailed explanation:

  1. Frequency Dependency: The higher the frequency of the signal, the greater the loss in the coaxial cable. This is because higher frequency signals have more difficulty penetrating the dielectric material of the cable and are more susceptible to losses due to the skin effect in the conductor.

  2. Cable Characteristics: The amount of loss also depends on the type and quality of the coaxial cable. Different types of coaxial cables have different specifications, such as the diameter of the inner conductor, the type of dielectric used, and the construction of the shielding. For instance, cables with a larger diameter or those with a lower-loss dielectric material will generally have lower attenuation.

  3. CATV RF Frequencies: In the context of CATV, RF signals can range from very low frequencies (like those used for VHF channels) to much higher frequencies (used for UHF channels and broadband internet). The loss per unit length of the coaxial cable will generally increase with the frequency of these signals. This is why distribution systems for CATV often require amplifiers or repeaters at various points to maintain signal quality over long distances.

  4. Additional Factors: Other factors that can influence signal loss in coaxial cables include the cable length (longer cables have more loss), temperature (signal loss can vary with temperature changes), and any physical bends or damage to the cable (which can increase loss).

In summary, the loss in a coaxial cable is both a function of the physical properties of the cable itself and the frequency of the signals it carries, including those used in CATV RF applications.


Thank you for your inquiry. This is a relatively straightforward transition. You can use IRD's (unencrypted) or even Satellite STB's (Set-Top Boxes) with HDMI output and feed one or multiple 8-channel HDMI modulators instead of analog Holland analog modulators. The video quality will improve significantly.

Please check these 8-channel HDMI modulators; they are the key to producing digital QAM or ATSC channels that you can use for hotel distribution, just as you are currently doing with Holland.

You can use our IRD's if the signal is not encrypted; otherwise, you need to use Direct TV's or other satellite providers' STB's with HDMI output. We can use our IRD with encrypted signals, but you would need to have the provider's CAS Cards available.



Gracias por su consulta. Esta es una transición relativamente sencilla. Puede utilizar los IRD (no encriptados) o incluso los decodificadores de satélite (Set-Top Boxes) con salida HDMI y alimentar uno o varios moduladores HDMI de 8 canales en lugar de los moduladores analógicos de Holland. La calidad de video mejorará significativamente.

Por favor, consulte estos moduladores HDMI de 8 canales; son la clave para producir canales digitales QAM o ATSC que puede utilizar para la distribución en hoteles, tal como lo está haciendo actualmente con Holland.

Puede utilizar nuestros IRD si la señal no está encriptada; de lo contrario, debe utilizar los decodificadores de Direct TV u otros proveedores de satélite con salida HDMI. Podemos utilizar nuestros IRD con señales encriptadas, pero necesitaría tener las tarjetas CAS del proveedor disponibles.

Please let me know if that would work for you.
Por favor, avíseme si eso funcionaría para usted, tenemos precios especiales de exportación disponibles

I'm going to show you a quick demonstration of the new firmware we just developed for the Thunder 4, one of our most popular models. So, from our website, thorbroadcast.com, I'm going to give you a quick glimpse of that, and again, nothing else changed. We still have the NMS on the front. You have your power and link lights right here to show it's on. You can also set up these units using the D-pad and the buttons right here on the back. Very simple RF in, RF out for HDMI inputs. And you guys can read more about it here, look at some of the older videos, and obviously, at the bottom, PDFs manual.

Okay, so I just plugged in a Blu-ray player or DVD player; it is a Blu-ray 3D Samsung. So, I just plugged it into Port one; it's actually on this side. So, this is Port four. If you're going to the splash screen of the unit, this is Go ahead and log into the unit; admin/admin. From here, you can see that this is a brand new unit out of the box; it already picked up the first HDMI input. Okay, so right from the status screen, you can see that I don't have anything else plugged in except for the first input.

Then you can click on the encode section, and you have all your inputs right here; two, three, four. So for the first one, you can change your bitrate from 525; you can set that out whatever you like, latency 500, 800,000. And we've received some different information about this; this is what we consider to be the fastest setting is 500, but in reality, I think it's probably much faster. There are certain things that pertain to that latency, specifically how fast the encoding is, meaning the resolution of whatever your input source is. So, something at 720p is going to go much faster than 1080p60. I think it's around 200 milliseconds, maybe even faster. But every infrastructure is going to be slightly different, depending on the TV, the receiver in the TV, and things of that nature. So, it's not a definitive, you know, fast, medium, slow, but you can set it up however you like. Again, this is just a ballpark figure. I think it's significantly faster than 500 milliseconds, in either case.

The next section here is AC3 for the audio, MPEG-1 Layer 2, and AAC. You have your TSID number, program number, program name you can change to whatever you like. This one I'm going to change to Blu-ray again. PIDs, your input source is just going to be HDMI on this particular model. And again, you see the status; it's on, it's spinning, and right here you can see we're at 1080i60. All right, make sure you hit apply to save your settings each time you change anything like adding in information. And if you change your sources or plug in different HDMI products, just press get, and it should just pop everything up here in the module eight section. Again, we're making this super easy, built-in attenuator for RF power. Your standards are all built in dvbt; this is nxa, which is European, generally speaking; atsc, that's American off an antenna. J3B is what we're using here for quam, and IDBT, which is another International standard. But you can set it up for quam or atsc, depending on what you're trying to do. Change your constellation, major and minor Channel, and again, on our website, you can go ahead and grab things like the quam chart and the atsc chart and look up your frequencies that you want to create those channels on. Use them major and minor channels, and it's that simple. And you can do that for each independent Channel; you can actually put each one, whatever Channel you like. All right, so it will take up the entire carrier; you can't put two programs on the same RF carrier on this model specifically. We do have other models like the H-4 ADHD that one will allow you to put up to four HDMI inputs on one RF Channel. With a thunder, you cannot do that; each one of these inputs will take up an entire RF channel. So, once you're done setting everything up on whichever channels you like, see as soon as I started putting in 57 MHz for channel two, this jumped to channel two, hit apply, it's going to save, and you're done. And that's it, quick and easy. The rest of the settings, your network password, you can change firmware and configuration, factory settings, save your configs. It's especially important once you're, you know, if you're in a setting where you might have 10 of these for 40 channels, you're in a hotel; you're going to want to save each one independently. God forbid all the power goes out or something like that. As soon as you power these back on, the settings will come right back into place, so it's important to save your config, you know, however you like in case you need them at a later point. But when you're going through the actual settings and you hit apply, that's good enough for the unit to remember what your settings are. Okay, and that's it, guys. If you have any questions, you can reach out to us at Thorbroadcast.com or call 1-800-521-8479.

As I noted previously yes you can take an HDMI device and convert it to ATSC. This is a simple straightforward application called modulation. 
The second part as you noted includes closed captions, which I then tried to explain that closed captions are NOT passed along with HDMI signals during modulation. 
Closed Captions require and necessitate a second input from the data found in LINE 21. We apply LINE 21 data to the audio and video from the HDMI through a second input. 
Will the Firestick work with the PETIT? YES it will
Will the ATSC channel have CC on it? NO it will not
Hence why I showed you a different product. 
Here is another iteration of what I'm trying to explain to you. 
This is a 4 port HDMI modulator and will work with your Firestick, no CLOSED CAPTIONS
This is another 4 port modulator but it has 4 additional inputs for CC - this will work!
However, back to the original point; a firestick does NOT have an additional output for Line 21 data; so you will not be able to modulate that device with CC with any product. 
I know this is a sticking point for you, so I'll clarify further that without the additional CVBS input carrying that data, you will not have closed caption via any device. 
The reason why you can do CC with HDMI through set top boxes, like this one from DIRECTV is because you have both the HDMI and the CVBS coming out of the box. (FIRESTICK does not, so you can not)
So in the case of APPLE TV, FIRESTICK, PLAYSTATION' you can modulate and put these devices on ATSC channels, however you will not have Closed Captions since they lack the appropriate inputs/outputs. 
The obvious alternative is just getting a new Television; that's always an option. 

Hope this helped clarify that for you. 


Thank you for your questions. Please find my answers  below:
1- What type of devices we can use from Thor to implement this solution. - H-THUNDER-8
2- Will it be IPTV over coaxial. - NO
3- Will we use the existing coaxial cables. -YES
4- What type of TV sets should we use. TV's with RF runners, F-type input
5- Is there a middleware to be used with this type of service. -NO
6- Will we be able to integrate with hotel PMS system. -NO
7- If we have channels that received on satellite receivers with HDMI output, how can we broadcast it over coaxial.- Please read the explanation below:
The easiest way to implement your project would be to use multiple 8ch HDMI modulators and combine them together.
For example, if you want to create 32 channels, you would need 32 HDMI sources from any device, such as DVD players, satellite STBs, local over-the-air decoders, or IPTV devices like Roku STBs. You would connect all of them to our modulators, and we would create a 32-channel modulated CLEAR QAM or DVB-T signal.
Every TV connected to your existing or new coaxial network can receive this signal. Basically, every TV with a QAM tuner can scan the channels, and you can change them using the remote control.
So, you would create a passive network where the channels are available anywhere on the coaxial network. Please check this application drawing for more information.
Let me know if this is clear or if you have any further questions.

User's Manual is avalible only for logged users.
User's Manual is avalible only for logged users.
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