RDR-HXD870 can't tune channels

[jotwedd]

The recorder has been trouble-fee for years, but a few weeks ago I had problems with losing some TV channels.  It also caused interference with the TV when switched on.  Upgraded firmware to 1.7 and seemed to be solved - but now it's worse than ever.  Will only find 37 Freeview channels.  I've tried all suggestions: re-installed firmware; factory re-set; unplug for a few minutes; clear the channel list; split co-axial aerial feed from TV, etc - but no joy.  The signal check shows that it gets a signal only on RF channels 22 and 25 (failing on 28, 31, 32, 34, 35, 55), yet the TV gets a good signal on all.  We are not far from the transmitter, so I don't think the aerial is an issue.  Anyone had a similar problem?  Any advice appreciated.

[Mooly01]

Are you using the HDMI connection from the recorder to the TV?

If so then that could be a possible clue (re the interference on the TV) and might in fact point to low signal levels. The HDMI lead can radiate interference and this can corrupt reception if the cable is near to an aerial lead. So don't automatically rule out low signal strength just because the TV seems OK. The signal could be marginal and the TV just manages OK.

Try your aerial feed directly into the recorder if it isn't already set up like this. 

There is no common issue on these (wonderful) machines for the problem you have that I am aware of. A definitive test would be to try the recorder in a different location (different house and aerial).

[jotwedd]

Hi Mooly - many thanks for response, you've helped me out before!  Yes, I'm using HDMI connection, did not realise that might be a cause.  I have an aerial splitter in the socket to feed the recorder and TV separately instead of the TV via the recorder.  I also tried unplugging the co-ax lead to the TV but that didn't help.  It's strange that it worked well since I updated the firmware, then went wrong.

I have another TV which uses a different aerial, so I'll try the recorder with that and let you know how it goes.

As it's not a common issue the problem must be with my set-up.

Thanks again.

[Mooly01 · Accepted solution]

Interesting... you have a similar set up to me then.

Although it is not impossible for the recorder to be faulty, it would initially be way way down the list of suspects.

HDMI connections can cause issues because the lead itself can radiate massive amounts of interference due to the nature of the HDMI signals it carries and this is particularly true if the lead runs close and parallel to the aerial lead. Some HDMI leads are better screened than others as to some are some coax aerial downleads.

Trying this on a different aerial is definitely the best option if you can do this easily.  

[jotwedd]

You've solved the problem!  I tested the Recorder on our other TV/aerial and it worked fine.  Put it back, this time moved the Recorder's co-ax cable as far away from the HDMI cable as possible and it worked fine .... until the next day when it lost some channels again - no signal!  I wondered if the interference was through the TV's co-ax cable via the splitter, as it was close to the HDMI cable.  I separated them as much as possible - and signal restored.  I've tested it again by moving the cables close together - and signal is lost.  So clearly it's the close proximity of the cables that was the cause.  I used satellite cable for the co-ax leads as I think they it's better screened than the normal cable, but not enough obviously.

Thank you again for solving problem.

[Mooly01]

Excellent, I'm pleased the recorder is OK.

Satellite cable is the stuff to use normally as that usually has the both the best shielding and lowest losses.

I'm going to hazard a guess that ultimately the real issue is possibly going to be one of marginal signal strength. One thing to consider (and this depends very much on which transmitter you are on) is that recent changes to Freeview have actually seen some geographical areas (such as North West England as an example) move from the top of the band to the bottom. In that situation and if you had an older 'grouped' aerial (that means an aerial designed to work at its very best with a very narrow range of the band) then it will perform really badly trying to pick up signals outside that narrow range.

Also of course, the signal may just be slightly low in level and so susceptible to interference.

It might be worth trying a different HDMI cable but it is very much a case of trial and error.

My own set-up has a roof aerial feeding a lowish gain 4 way distribution amplifier in the loft. A single feed from this amplifier feeds the main lounge and there it is split 3 ways with a passive splitter, one feed to the TV, one to the Sony recorder and one to a Panasonic recorder. With that set up I can add up to around 24db of attenuation to the Sony before it complains (that's a massive amount and more than a 10 to 1 reduction in signal).

So it may well be worth a look at the incoming levels/aerial etc.

Good luck