HDMI to COAX?

[sethrose]

I have a TiVo mini that has HDMI, A/V and component outputs. I want to hook it up to a recumbent bike that has a video screen built in. Problem is the bike only accepts coax. I tried using an RF converter converting the A/V out to Coax but the picture quality is terrible. Does anyone know of a better way to do this? An HDMI to coax converter of some kind? I've searched extensively but they don't seem to exist.....

[redwudz]

Try Monoprice: http://www.monoprice.com/product?p_id=9994
EDIT: Sorry, after a closer look at the converter, it DOES'NT output composite,
so won't work for you.

Maybe other members will have a better suggestion.

I don't know about how the quality may be, but unless you use a decent
RF modulator, that may be the problem.

And welcome to our forums.

[sethrose]

Thanks for the welcome!
Maybe that is the problem, the one I have was only $15.... the link provided only has HDMI out, not coax....

[usually_quiet]

Most RF Modulators are $20 or less. I saw a commercial grade product on Amazon (Holland Electronics HMM-10H) for around $54 that allows users to select more/different channels for its RF out. It may or may not provide better picture quality. You are converting from composite video to an NTSC analog channel. Both composite and NTSC analog channels are limited to standard definition. If you want better picture quality you may need to buy a TV with HDMI in.

[Cornucopia]

Yeah, an analog coax connection is EXPECTED to be terrible (compared to even SD digital HDMI), even with pristine sources.

Scott

[redwudz]

There are small HDMI monitors available, and this may be the best choice. If you don't need one too large, they can be very inexpensive.
Some from Amazon: http://www.amazon.com/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3Asmall%20hdmi%20monitor

Ebay likely has some also, but many of them are shipped directly from China and returns and shipping times are a concern.

[sethrose]

Thanks all, my issue is that the recumbent bike has a built in console that is also a monitor with a built in TV tuner, it only accepts coax so I need a solution to get some decent video over coax converted from either HDMI, component or composite video ( the output choices of my TiVo)

[jagabo]

Does it look much worse than the picture in this post?

https://forum.videohelp.com/threads/283861-VGA-to-S-video?p=1756748&viewfull=1#post1756748

That's about what you should expect via standard definition RF.

[usually_quiet]

Thanks all, my issue is that the recumbent bike has a built in console that is also a monitor with a built in TV tuner, it only accepts coax so I need a solution to get some decent video over coax converted from either HDMI, component or composite video ( the output choices of my TiVo)

No problem. Assuming the monitor has a digital tuner, it will only cost you about $900 (minimum) to get HDMI or component video from the TiVo to your itty bitty screen over coax.

You'll need something to remove HDCP copy protection from the TiVo's HDMI out, if you prefer HDMI. This is a cheap solution: http://www.amazon.com/ViewHD-Powered-Splitter-1080P-Model/dp/B004F9LVXC

...and you will need an ATSC RF modulator. This is a cheap one, believe it or not: http://www.pvistore.com/compact-hd-rf-modulator-1080i-p/

[lingyi]

@sethrose

Sorry for the long post, but trying to summarize all the above posts:

As has been pointed out, while it's technically possible to convert a Digital HDMI signal to an RF* signal** is possible, it's a costly*** proposal with no real benefit****

*Coax refers to the type of cable, RF is the signal sent through a coax cable
**Highly probable Analog
***Broadcast price equipment because those who would do this are TV broadcasters
****An RF signal is the lowest quality video signal, more below.


Okay, what can be done...

Be realistic with your expectations. View your TIVO through the composite output. This is still far better quality than you'll get though RF (as Jagabo pointed out above) There's nothing to be gained by using Component video or HDMI. A quick Google search points to Component RF modulators existing, but they're even rarer than HDMI modulators and still well within the broadcast TV realm.

Check your connections and cables. Analog quality is easily and greatly affected by bad connections and cables. Even the slightest gap in the shielding (due to an unseen internal break or bad plug) can allow interference.

Make sure your connections (input and output) connectors / connections are clean and tight. Use a well shielded VIDEO cable (don't use a generic audio cable) from your TIVO to your RF Modulator and high quality coax cable / RF connectors from your Modulator to your display. If you shake the cable(s) and the quality changes you have a bad connection or cables.

Switch channels and fine tune (if possible). Using Channel 3, switch to Channel 4 or vice-versa (or as usually_quiet posted, try a modulator with alternate channels. There are still low power TV broadcasters on the Low Band VHF channels (2-6) that can cause interference.

Use the RF modulator in a VCR or AV Receiver. These have better shielding (i.e. higher quality output) than your typical stand-alone non-broadcast modulator.

Follow redwudz's suggestion, get a mini -HDMI monitor and put it above, below or on top your existing monitor. Sadly, your console is outdated and the money and effort to try and get a half decent picture on it is virtually futile.

[lingyi]

Another thought.

In theory, it may be possible to have mod the console to accept a composite or possibly component video input. The tuner must output some type of "raw" video signal internally, yes???

[sethrose]

@jagabo yes, the images in your post are about what I see. I think I'll try the $50 modulator and see how that goes also I'll open up the console and see what the internal connections look like.

Question: They use the same bike that I have in gyms, seen there hooked up to coax they display a great TV image. What are they doing differently to send higher def video over coax? Do they use something like an ATSC RF modulator there?

[sethrose]

I just found this on Amazon... not sure though if it fits the bill?
http://www.amazon.com/Channel-Vision-CVT-1MINI-II-Miniature-Modulator/dp/B000LXQTOW/re...l+HD+modulator

[jagabo]

I just found this on Amazon... not sure though if it fits the bill?
http://www.amazon.com/Channel-Vision-CVT-1MINI-II-Miniature-Modulator/dp/B000LXQTOW/re...l+HD+modulator

That RF modulator offers a wider selection of channels but probably doesn't perform significantly better than the others. Thr problem you are having is the standard definition composite signal being fed to the modulator. To get better picture quality you need to move to high definition ATSC (over the air broadcast system) or QAM (cable TV system).

[usually_quiet]

Question: They use the same bike that I have in gyms, seen there hooked up to coax they display a great TV image. What are they doing differently to send higher def video over coax? Do they use something like an ATSC RF modulator there?

It is possible that they do use ATSC or QAM RF modulators to broadcast one or more digital TV channels internally. Other possibilities are that they have a TV service that doesn't encrypt the channels in the gym's subscription, or they have a roof antenna.

[Edit]

also I'll open up the console and see what the internal connections look like.

That advice from lingyi was irresponsible. I would not recommend opening up the monitor housing and poking around inside to someone unless I knew that person an electronics background. Also, a TV that has no video inputs other than RF to its tuner is very likely to be unable to do anything with analog or digital video and audio input from other sources provided via an improvised connection. The only internal connection for video is likely to be a ribbon-type connector from the main board to the display.

[lingyi]

[Edit]

also I'll open up the console and see what the internal connections look like.

That advice from lingyi was irresponsible. I would not recommend opening up the monitor housing and poking around inside to someone unless I knew that person an electronics background. Also, a TV that has no video inputs other than RF to its tuner is very likely to be unable to do anything with analog or digital video and audio input from other sources provided via an improvised connection. The only internal connection for video is likely to be a ribbon-type connector from the main board to the display.

I apologize if my post is viewed as irresponsible. I certainly didn't mean for the OP (or anyone without the electronics expertise) to attempt to mod or even open up his monitor, hence my preface of "In theory,".