All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
john tansley: Also meant to add, that the mast head amplifier itself can also suffer from the effects of an over powerful signal, and although this is not just so sensitive to overloading as is the receivers tuner, it can however sometimes partially block the signal rather than amplify it, this being the reason for my request to try using a set top aerial (purely for a test) as the results obtained would enable a better assessment to be made for the reason of the reportedly low signal.
That said though, a better assessment could be made with knowledge of the readings seen if you carried out a signal test using your TVs signal checking menu. (also of assistance to know the model of TV).
| link to this comment |
Dave Lindsay: All tuners have an element of automatic gain control built into their circuitry to reduce the input sensitivity in the presence of a strong signal, its a form of overload protection but which has its limits, and when these limits are exceeded thats when instability starts to take over resulting in all sorts of random problems.
| link to this comment |
Alan: If I could just add, that as Dave Lindsay has mentioned if your Sky+ box has two scart sockets then connect your DVD player into the second scart (usually marked VCR) and when "play" is pressed on your DVD player the DVD should over-ride the Sky+ box, if by any chance it doesn't then put the DVD back in standby likewise the Sky+ box, then press "play" again on the DVD.
If though your DVD player has an HDMI connection then just use an HDMI connector lead between both, using No1 HDMI input on your TV which usually has auto detect sensor to switch over to that input should it detect a signal on it.
One main problem though, "if" your Sky+ box is an HD type and of the later variety, then it might only have one scart socket, and which unfortunately I believe is an output. (only)
| link to this comment |
Bob: Any device whether Satellite or terrestrial Freeview that has an RF output facility to feed another TV is always in analogue.
I don't quite understand though what you mean by nothing after switchover, as if the Philips boxes RF output was feeding its analogue output to the portable TV then this would not change, so are you meaning that the Philips box isn't receiving Freeview now? and should this be the case then maybe you could mention the model of the box in question to enable aspects of its specification to be checked upon.
| link to this comment |
julie: It could well be a box problem if your device is a few years old, so maybe you could give an update on the model you are referring to, plus of course your location (pref post code) to enable your reception possibilities to be assessed.
| link to this comment |
Sammy: Your problem could be caused by various reasons and which might not be easy to rectify, you probably find it easier if you had purchased a scart to composite output converter lead (even pound shops sell them) and connected the phono plugs on the said lead into the input sockets on the rear of your Sony, as these are for that purpose.
Sockets by the way, being behind the thin plastic panel on the rear of the set, the lead referred to having a scart socket on one end and three phono plugs on the other, the yellow one being the video.
| link to this comment |
Bob: Just a point of clarification, my initial "RF output to feed another TV" statement means RF modulator output facility.
| link to this comment |
Nick: The manual for your BTW700 doesn't indicate that there is any anything of an RF nature (e.g: modulator) in the DVD that can cause a clash with an incoming channel, this making me suspect that Ch63 which for many people is notoriously difficult to pick up, is only being received and no more by yourself but is dipping under the reception threshold when you activate the DVD.
To test if this is applying, carry out a signal strength check on your TV whilst viewing something on Ch63 then do the same after switching the DVD on, as even although the TV will have a blank screen the signal level will still be indicated in the level checking menu.
Before you do that though, you could maybe try another test to eliminate the possibility of interference radiating from the DVD itself killing the signal, so once again whilst viewing the blank screen on the TV pull the aerial lead out of the DVD but leave it (the lead) lying across the top of (or near to) the DVD casing, if the TV comes back on its not interference. If though you are using the aerial through the DVD to feed the TV, just link the two leads (in / out) together for the test.
You haven't actually mentioned the method anything about your aerial feed arrangements to the TV or the DVD, but it might end up that you will require to split the aerial via a two way powered splitter with individual feeds to each device, as that's the only way of guaranteeing that each gets the same level of signal.
Anyway, if you could give an update on the tests further advice can be given.
| link to this comment |
John Swift: The two leads from the dish are totally independant of each other and so you just leave one of them unconnected to anything.
Although its not good practice to join satellite cables in an ordinary junction box as you should really use an "F" plug on each cable to be joined and a coupler piece to link the two "F" plugs together, you will though be OK with what you are doing so long as none of the fine wires that make up the screen accidentally touches the inner connection.
By the way the previous occupier either used Sky+ or they had a Freesat recorder, as twin inputs are necessary for both the mentioned.
| link to this comment |
Sunday 4 December 2011 10:02PM
john tansley: Being located at only 9 miles from Tacolneston and using the type of aerial system described, your receiving equipment is very likely to be suffering from its tuner being overloaded, and it should be pointed out that in this type of situation the readings you will see of the signal strength etc can be totally inaccurate.
I would normally have requested you try by- passing the amplifier, but with a mast head type that's not possible, so purely for a test try a set top aerial and see what indications you have from that, although the best test of all is to insert an attenuator in line with the aerial socket.
In other words, the symptoms of an overly powerful signal are exactly the same as that of a weak one, this being the aspect that misleads the unwary.