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Hi all,

I have bought one of the hong kong video systems, unlike most that have the transmitter and camera as one unit the one I have has a seperate Tx as shown.

Having read posts that state the Tx/cam unit operate at 1.1GHz I was wondering if this is the case for this Tx unit?

Main reason is that I intend to make the patch anntena and require the correct frequency for scaling.

I have no test equipment so I dont know how I can test for the exact frequency.

Having read posts I know 2.4GHz systems are the best, but this was cheap and I can change the camera to a CCD. The Tx claims to be 800mW and does get quite warm when running so can I expect reasonable video when using the patch.

Oh I should say that my usage will be video from general flying about and not long range remote piloting.

Anyone with views, options or experiences?

Cheers Rob

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At the end of the day Rob you just have to give it a go !

These HK things are not the best but for the general flying you say you will do it should be fine. If you intend to do any aerobatics then you may get some drop outs,let us know how you get on.

Terry

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Hi Terry

Thanks for the reply, do you think it would be possible to change the 1.2GHz decoding module can inside the receiver with a 2.4GHz module from one of the site you mentioned in an other post?

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For the time and effort you would be better served by just getting another set in 2.4 ghz.

They're not that expensive. For just general flying the set you have should do fine. I fooled with one of those exact sets for a while and although it was a hassle having to keep retuning it, it had really good range and video quality.

The better ones have a four position switch instead of a rotary tuner......

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Like Randall says its not worth trying as theres lots of reasonally priced 2.4ghz stuff you can get in the UK and to be honest the chance of success is very low. See how you get on with what you have and when you know exactly what you want from a video link you can buy all the right bits !

Terry

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Hi I bought a similar 800mw setup. The true power output is around 200mw.

I rematched the Tx aerial and tweaked the video input and the quality is now superb.(as good as any 2.4ghz setup in this price range) It also has sound as well.

I know the RX tuning can be an issue, however run the TX on a 1000ma AR or AAA 9.6volt pack and you wont have any more problems. It also puts out a bit more power. The 9volt transistor radio batteries are a no no as you will be constantly re-tuning. I have also found that 1.2ghz setups have slightly better range especially in more built up area's.

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Hi Modelman

When you say you rematched the Tx aerial and tweaked the video input what exactly did you do?

Your results sound great as most knock the 1.2 systems, me I like cheap and cheerful :rolleyes:

Did you try the GP patch antenna on your system.

Cheers Rob

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Oh just read your posts about GP patch Modelman, was the frequency you tested for a combined cam/Tx or the standalone Tx as above?

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That doesn't matter.........it will transmitt on the same frequency whether or not it has the camera on it.

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Sorry randall1959 you miss my point. There is a small camera that has a transmitter built into it, and then there is the seperate transmitter which you have to attach a camera to, like the unit I have.

My question was does the standalone transmitter transmit the same frequency as the combine camera/tx. I was wondering which of the two had modelman tested and found to be operating at 1.1GHz.

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ah ok.........sorry for the missread. You know, for around 99 bucks you can get a fequency counter that will read just about any freq you can throw at it. Radio shack sells one.

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Hi Robe_uk

The aerial on my TX was not as good as yours. It was just a piece of wire. I simply calculated the correct length for the TX frequency which was 1.106ghz. Tested on a field strength meter and power meter.

My TX has a pot on it for video signal adjustment. The signal from the camera was overloading the input and making the picture contrast too strong. I simply reduced it for the best picture quality.

For best performance in range build the GP Patch you won’t regret it. As Randall rightly said a frequency counter is useful as there are many channels allocated in the 1.1/1.2ghz bands. The GP Patch needs to be built accurately for best results as it only has a 3% bandwidth

I have got both a standalone and build in TX setup. Both are in the 1.1ghz band but classed as 1.2ghz, typical of Hong Kong Cams.

Simple test : plug a camcorder into your TV and note picture quality

Now plug TX into camcorder and transmit signal to your TV via RX.

Compare the difference. After slight tweak my TX and RX picture was almost identical to the direct link.

Edited by modelman

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