All posts by Mike
Below are all of Mike's postings, with the most recent are at the bottom of the page.
Rob, just found this site TETRA and television interference from the national research-based TETRA Airwave safety campaign which says that interference from Tetra is more likely to be on Channel 60 (analogue in this 2005 case).
How far are you from the Police Tetra transmitter?
If you are in north west Kidlington, is your aerial pointing at the police transmitter when pointing to Oxford TV transmitter? If so, pointing the aerial a few degrees off will help.
If not too far away then any mismatch in the coax caused by breaks or unterminated spitters/ coax etc could allow this intermittent signal in. It is a harmonic of the radiated Tetra transmission so you would have to be reasonably close.
If you put in a Tetra filter it MUST be on the input side of any distribution amplifier, if you use one. Putting on the output or at the tv will not work as the distribution amp is reasonably wide-band and likely to have already amplified the interfering signal.
Incidentally, 4G causes interference on CH 59 as shown here
Labgear F4GA Official at800 4G TV Filter | Maplin
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Rob, I used to travel to the Far East to do technical appraisals on SMPS and their manufactures. There is a lot of product that claim to meet the standards for conducted and radiated noise - and even have the right markings - but in fact do not.
Often the SMPS has the space on the pc board for the conducted EMI filters but the components are just not fitted (cost saving?).
Even big name buyers of SMPS get caught out unless they use a well respected assurance company to vet each batch before shipment. VM may be very glad that you have identified a faulty batch or a poor supplier.
I have one here that meets the standards but still causes interference on an FM radio when plugged into a socket which is on a spur from the one powering the SMPS.
Similar problems are arising now from the so called Power Line Adaptors which use mains wiring to give internet access to a pc that is remote from the router.
Glad you are finally getting somewhere.
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I see that Quest and Quest+1 are advertising moves to channel numbers 37 and 38 respectively from next Tuesday. Anyone know of any other retuning required on that day other than to Com 4 and Com 5?
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To partially answer my own question above, the only other main channel that has moved is ITV4+1. It is now on channel 26/com4
Also some sales channels have moved or changed name. The full channel list above needs updating.
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Quinnicus,
I had a small blip too on Monday but put it down the fact I am currently using a C/D aerial and trying to watch channel 31 (Com 7) programmes when it happened. What group aerial are you using?
Must buy a wideband or log periodic aerial soon as more of the lower frequencies will come into use.
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I found I had lost Film 4+1. I had to retune PBS 3 as it has been moved. It is transmitted now on C57. Still comes up on the EPG as programme 45. So if you have lost Film 4+1, just do retune.
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Yes, I forgot to say that people trying a retune will not be able get Film 4+1 on a non HD receiver anymore.
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Simon:
No problems in the Highworth area from the Oxford Transmitter so must be somewhere in your installation. On one occasion I had this when a light bulb failed and tripped the circuit breaker for a few lights. It was the also the power source for my aerial amplifier!
Check your aerial leads are pushed in fully and as a last resort do a re-tune.
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Here near Swindon I changed from a C/D to a wideband aerial and That'd Oxford test transmission is quite strong considering the low power. Quality is good and no drops out even in different weather conditions.
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Thursday 23 January 2014 3:11PM
Rob, don't take the connectors off as we are looking for a poor connection in the connector.
If you have taken the connectors off the when you put them back do this;
1) put a small kink in the central wire to ensure it is making contact inside the pin
2) after putting it back together, connect your multimeter on the ohms range between the inner and outer of the connector. It should read Infinity.
3) do the test in my previous post but using the multimeter instead of a battery and torch bulb. Reading should be around zero ohms