Sagem vs Humax

akpak

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I've recently bought a Sagem DTR67250T but I'm having frequent (but intermittent) problems with picture and sound breaking up/pixellation/freezing. I'm about 20 miles from the transmitter (Waltham) and my aerial was installed specifically for Freeview about 3 years ago. Strangely, the picture and sound on the TV are fine, even though the RF signal passes through the Sagem (and a DVD recorder) before it gets to the TV.

I'm considering returning the Sagem as not fit for purpose and possibly getting a Humax PVR 9150T or 9300T - but is it likely to be any better? Or are there any other twin-tuner recorders worth considering?

Alternatively, as I'm getting a bit fed up with Freeview, would Freesat be subject to the same kind of reception problems?

Thanks for any help.
 
Provided your dish is aligned correctly and is large enough for where you are and you have a location with a direct line of sight to the satelittes you should get a a flawless signal. In the South of the UK a sky minidish should be fine.
 
Thanks for that info - something to bear in mind if I ever do go the satellite route.

Meanwhile I've been doing a bit more research: from the specs of the different models I've noticed that the RF input level of the Sagem is -90 to -20 dBm, whereas the Humax signal level (which I take to be the same thing) is -70 to -10 dBm. I'm not a techie and have no idea what these figures mean, but I'm wondering if it's a measure of the tuner's sensitivity, and whether the difference between them might point to one being more suitable than the other for where I am.
 
The Sagem claims to be more sensitive than the Humax (dBm means dB relative to a milliVolt = 1/1000 of a Volt) and it will not handle very high levels of signal as well as the Humax.

If your aerial large and is highly amplified it might be overloading the Sagem?? (The TV being better able to cope with such a signal?). Signal overload can give similar symptoms to lack of signal by, effectively, lowering the quality.

Does the Sagem have a signal strength and quality meter (in manual tune mode for instance) that will allow you to gauge if there is something wrong here - especially if you can compare the figures to the TVs tuner.

Strictly, this thread belongs in the PVR section PVRs and VCRs Forum at AVForums.com and it might be worth you looking over there to see if others have had similar problems with the Sagem.
 
Thanks for the reply and explanation - I've started a thread on the PVR board as you suggested.

I don't think the aerial is over-large, and it's certainly not amplified. I wrote some more about the problem here; if you go there you'll see that the Sagem is reporting signal strength around 40-50%, with quality mostly at about 98% but then rapidly fluctuating between that and 2%, which is presumably when I get problems. (The meters cover the whole screen, so I can't see what the picture is doing.) The TV doesn't have separate strength and quality meters, but consistently reports the strength as 100%.

A previous STB generally reported the strength as around 40-70% (again, no quality figure), and that had started having the same issues as the Sagem. Since the TV was fine, I'd thought maybe the box was on its way out, but since it now seems the problem may be elsewhere, I'd like if possible to get a recorder that will actually work and not be continually breaking up.
 
Thanks for that info - something to bear in mind if I ever do go the satellite route.

Meanwhile I've been doing a bit more research: from the specs of the different models I've noticed that the RF input level of the Sagem is -90 to -20 dBm, whereas the Humax signal level (which I take to be the same thing) is -70 to -10 dBm. I'm not a techie and have no idea what these figures mean, but I'm wondering if it's a measure of the tuner's sensitivity, and whether the difference between them might point to one being more suitable than the other for where I am.

The "m" bit of "dBm" means relative to 1mW. That is 0dBm = 1mW

As dB is a logarithamic measure then a change of 3dB is twice power and 10dB is 10 times power. . . .. or sensitivity. . . . .and of course as 0 dBm is relative to 1mW you can have -ve dBm values!

So your Sagem will work down to -90dBm Rx signal where as your Humax will only work down to -70dBm Rx signal.

In a nut shell: your Sagem has a tuner that is 100 times more sensitive than the Humax.

At the other end of the scale the Sagem would have signal overload if the Rx strength were above -20dBm but the same wouldn't apply to the Humax unless the Rx signal strength were above -10dBm.

I hope my post has been of use :)
 
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Thanks - as far as I can tell the signal here seems to be too weak rather than too strong, but if I'm wrong this will be something to bear in mind.
 
Thanks - as far as I can tell the signal here seems to be too weak rather than too strong, but if I'm wrong this will be something to bear in mind.

Looking at wolfbane, UK digital TV reception predictor at 20 miles that would seem a correct assumption. MUX C & D are only 5Kw ERP.

Putting aside terrain for a moment I'm 20 miles from Sandy Heath which has an ERP of 20Kw and I'm in a fringe area. For my location the wolfbane predictor states "Amplified extra hi-gain" which is really a bit of an understatement"!

I hope my post has been of use :)
 

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